## Maharashtra Board Class 11 Chemistry Important Questions Chapter 7 Modern Periodic Table

Balbharti Maharashtra State Board 11th Chemistry Important Questions Chapter 7 Modern Periodic Table Important Questions and Answers.

## Maharashtra State Board 11th Chemistry Important Questions Chapter 7 Modern Periodic Table

Question 1.
Mention features of Mendeleev’s periodic table.
Features of Mendeleev’s periodic table:

• In Mendeleev’s periodic table, all 63 elements were arranged in an increasing order of their atomic masses. The serial or ordinal number of an element in the increasing order of atomic mass was referred to as its atomic number.
• Mendeleev’s periodic table consisted of vertical groups and horizontal series (now called periods).
• Elements belonging to the same group showed similar properties.
• Properties of elements in a series/period showed gradual variation from left to right.

Question 2.
Why was Mendeleev’s periodic table readily accepted by scientific community?
Mendeleev’s periodic table was readily accepted by scientific community due to the following advantages:
i. Mendeleev had left some gaps corresponding to certain atomic numbers in the periodic table so as to maintain periodicity of the properties. When the elements corresponding to these atomic numbers were discovered, they fitted well into the gaps with their properties as predicted by Mendeleev’s periodic law.

ii. Mendeleev did not predicted presence of inert gases, however, they were discovered in later years. It was possible to accommodate inert gases in Mendeleev’s periodic table by creating an additional group without disturbing the position of other elements in his periodic table.

Question 3.
Give reason: Mendeleev’s periodic law was modified into modern periodic law.

• Henry Moseley in 1913, studied X-ray spectra of large number of elements.
• He observed that the frequency of X-ray emitted from an element is related to atomic number (Z) of an element and not its atomic mass.
• Therefore, the atomic number, Z, was considered as more fundamental property of the atom than the atomic mass.
• As a result, Mendeleev’s periodic law was modified.

Question 4.
Define atomic number.
Atomic number (Z) is the total number protons present in the atom of an element.

Question 5.
State the modern periodic law.
Modern periodic law: “The physical and chemical properties of elements are a periodic function of their atomic numbers”.

Question 6.
Periods and groups present in the modern periodic table are numbered based on whose recommendation ?
Numbering of the periods and groups in the modem periodic table is based on the recommendation provided by the International Union of Pure and Applied Chemistry (IUPAC).

Question 7.
Write a note on: Structure of the modern periodic table.
Structure of the modern periodic table:
i. The modem periodic table also known as the Tong form of periodic table’ has number of boxes formed by the intersection of horizontal rows and vertical columns.
ii. The horizontal rows are called periods and the vertical columns are called groups.
iii. There are seven periods numbered from 1 to 7 and eighteen groups numbered from 1 to 18.
iv. There are total 118 boxes in the modem periodic table which are filled with 118 elements discovered till now including manmade elements.
v. The modem periodic table is divided into four blocks i.e., s-block, p-block, d-block and f-block.

• Two groups on the extreme left of the modem periodic table form the s-block.
• Six groups on the extreme right constitute the p-block.
• Ten groups in the centre form the d-block
• Two series at the bottom of the modem periodic table constitute the f-block. It contains fourteen elements in each series.

Question 8.
State the relationship between the modern periodic table and electronic configuration in periods.

• The modem periodic table is based on the atomic numbers of the elements. When elements are arranged in an increasing order of atomic number (Z), periodicity is observed in their electronic configurations which reflects in the characteristic structure of the modem periodic table.
• The location of elements in the modem periodic table is correlated to quantum numbers of the last filled orbital.
• Along a period, the atomic number increases by one and one electron is added to the outermost shell which forms neutral atom of the next element.
• The period number is same as the principal quantum number ‘n’ of the valence shell of the elements.
• A period begins with filling of a particular shell and ends when the valence shell attains complete octet configuration (or duplet, in case of the first period).
• The next period begins with addition of electron to the next shell of higher energy compared to the previous period. e. g. First shell of the elements gets filled along the first period while second shell starts filling in the second period and addition of electrons continues till second shell (valence shell) attains stable electronic configuration.

Question 9.
Give reason: First period in the modern periodic table contains only two elements.

• Elements present in the first period i.e., H and He contain only one shell which is also their valence shell and can accommodate maximum two electrons.
• As first shell can accommodate only two electrons, first period ends at He which has a complete duplet. Hence, first period in the modem periodic table contains only two elements.

Question 10.
Write names and electronic configurations of elements of first period in the modern periodic table. Identify which of them has the stable complete electronic configuration.

• Hydrogen (H) : 1s2, Helium (He) : 2s2
• Since helium has a complete duplet i.e., two electrons in its valence shell, it has the stable complete electronic configuration.

Question 11.
Explain how does the filling of electrons takes place in the modern periodic table across:
i. Second period
ii. Third period
i. Filling of electrons in the second period:

• In the second period, electrons are filled in the second shell i.e., n = 2.
• This shell can accommodate a maximum of eight electrons and gets filled as the atomic number increases along the second period.
• The second period begins with Li (Z = 3): 1s2 2s1 and ends up with Ne (Z = 10): 1s2 2s2 2p6.
• Neon has complete octet with 8 electrons in its valence shell. Therefore, the second period contains eight elements.

ii. Filling of electrons in the third period:

• The third period corresponds to the filling of the third shell i.e. n = 3.
• The third period also contains eight elements.
• It begins with the filling of electrons in the first element Na (Z = 11) : [Ne] 3s1 and ends with the last element Ar (Z = 18) = [Ne] 3s2 3p6.
• The condensed electronic configurations for the elements of third period is [Ne] 3s1-2 3p1-6.

Question 12.
There are 18 elements in the fourth period of the modern periodic table. Explain.

• The fourth period corresponds to the filling of fourth shell, n = 4.
• Therefore, it begins with filling of 4s subshell. The first two elements of the fourth period are K (Z = 19) : [Ar] 4s1 and Ca (Z = 20) : [Ar] 4s2.
• According to the aufbau principle, the next higher energy subshell is 3d, which can accommodate up to 10 electrons. Thus, filling of the 3d subshell results in the next 10 elements of the fourth period i.e., from Sc (Z = 21) : [Ar] 4s23d1 to Zn (Z = 30): [Ar] 4s23d10.
• After filling of 3d subshell, the electrons enter the 4p subshell which can accommodate maximum 6 electrons. Hence, filling of 4p subshell results in the next 6 elements i.e., from Ga (Z = 31): [Ar] 4s23d10 4p1 to Kr (Z = 36): [Ar] 4s2 3d10 4p6.
• Thus, the elements in fourth period are: 2 elements (with 4s subshell), 10 elements (with 3d subshell) and 6 elements (with 4p subshell).
• Hence, there are 18 elements in the fourth period of the modem periodic table.

Question 13.
Why does the fifth period of the modern periodic table contain 18 electrons?
The fifth period accommodates 18 elements as a result of successive filling of electrons in the 5s, 4d and 5p subshells.

Question 14.
What is the general trend followed while filling of electrons across a period in the modern periodic table.

• A period begins by filling of one electron to the ‘s’ subshell of a new shell and ends when an element corresponding to the same shell attains complete octet (or duplet).
• Between these two ‘s’ and ‘p’ subshell of the valence shell, the inner subshells ‘d’ and ‘f’ are filled successively following the aufbau principle.

Question 15.
What is the subshell in which the last electron of the first element in the 6th period enters?
The 6th period begins by filling the last electron in the shell with n = 6. The lowest energy subshell of any shell is ‘s’. Therefore, the last electron of the first element in the 6th period enters the subshell ‘6s’.

Question 16.
How many elements are present in the 6th period? Explain.

• The 6th period begins by filling the last electron in the subshell ‘6s’ and ends by completing the subshell ‘6p’. Therefore, the sixth period has the subshells filled in increasing order of energy as 6s < 4f < 5d < 6p.
• The electron capacities of these subshells are 2, 14, 10 and 6, respectively. Therefore, the total number of elements in the 6th period is 2 + 14 + 10 + 6 = 32.

Question 17.
How does electronic configuration vary down a group in the modern periodic table?

• As we move from top to bottom in a group, a new shell gets added successively in the atom of an element. Therefore, the last electron enters in a new shell down the group.
• Hence, the general outer electronic configuration of the elements in a group remains the same. This holds true for groups 1, 2 and 3 elements.
• In the groups 13 to 18 the appropriate inner ‘d’ and ‘f’ subshells are completely filled and the general outer electronic configuration is the same down the groups 13 to 18.
• However, in the groups 4 to 12, the ‘d’ and ‘f subshells are introduced at a later stage (4th period for ‘d’ and 6th period for ‘f’) down the group. As a result, variation in the general outer configuration is introduced only at the

Note: General outer electronic configuration in groups 1 to 3 and 13 to 18.

Question 18.
On what basis is the modern periodic table divided into four blocks?
The modem periodic table is divided into four blocks based on the subshell in which the last electron enters.

Question 19.
Why elements of group 1 and group 2 are known as s-block elements?

• The subshell in which the last electron enters decides the block to which an element belongs.
• In group 1 and group 2 elements, the last electron is filled in the s subshell.

Therefore, the elements of group 1 and group 2 are known as s-block elements.

Question 20.
Elements belonging to which groups constitute the p-block and why?

• Elements belonging to groups 13, 14, 15, 16, 17 and 18 constitute the p-block.
• The last electron in the p-block elements is filled in p subshell.
• As p subshell contains three degenerate p orbitals, it can accommodate up to 6 electrons.
• Therefore, the p-block elements belonging to six groups i.e., groups 13, 14, 15, 16, 17 and 18 in which last electron enters in p subshell constitute the p-block.

Question 21.
Give reason: Helium which is the first element of group 18 is placed in the p-block even though its last electron enters in s subshell.

• Electronic configuration of helium is 1s2 which indicates that it has a stable electronic configuration i.e., a complete duplet.
• The p-block ends with group 18 which is a family of inert gases having stable electronic configuration (complete octet except helium).
• Therefore, helium is placed with group 18 elements in p-block due to its stable electronic configuration even though its last electron enters in s subshell.

Question 22.
State the general outer electronic configuration of s-block and p-block elements.
The general outer electronic configuration of s-block elements is ns1-2.
The general electronic configuration for the p-block elements is ns2np1-6.

Question 23.
There are total 10 groups in the d-block of the modern periodic table. Explain.

• The d-block in the modem periodic table is formed as a result of filling the last electron in d orbital.
• As there are five orbitals in a d subshell, 10 electrons can successively be accommodated.

Hence, there are total 10 groups in the d-block of the modem periodic table i.e., group 3 to 12.

Question 24.
The last electron enters a (n-1)d orbital only after the ns subshell is completely filled. Explain.
A d subshell is present in the shells with n ≥ 3 and according to the (n+1) rule, the energy of ns orbital is less than that of the (n-1)d orbital. As a result, the last electron enters a (n-1)d orbital only after the ns subshell is completely filled.

Question 25.
Chromium exhibit 4s1 3d5 electronic configuration instead of 4s2 3d4. Explain.

• Completely filled or half-filled subshells are highly stable.
• In 4s1 3d5 configuration, both s and d subshells are half-filled.
• Thus, due to the extra stability associated with half-filled subshells, chromium exhibits 4s1 3d5 electronic configuration instead of 4s2 3d4.

Question 26.
What is the general outer electronic configuration of d-block and f-block elements?
The general outer electronic configuration of the d-block elements is ns0-2 (n-1)d1-10 while the general outer electronic configuration of the f-block elements is ns2 (n-1)d0-1 (n-2)f1-14.

Question 27.
Expected outer electronic configuration of europium (Eu) is 6s2 4f6 5d1. However, it exhibits different than expected outer electronic configuration.
i. Write the observed outer electronic configuration of Eu.
ii. What is the reason for this variation in electronic configuration?
i. Observed outer electronic configuration of europium (Eu) is 6s2 4f7 5d0.
ii. In the observed electronic configuration of Eu, 4f subshell is half-filled which is a highly stable configuration. Therefore, observed electronic configuration of Eu varies than expected.

Question 28.
Name the two series that constitute f-block.
The f-block constitutes two series of 14 elements called the lanthanide and the actinide series which are placed one below the other.

Question 29.
State whether the following statements are true or false. Correct if false.
i. Position of the elements in the modern periodic table is related to the quantum number of their last filled orbital.
ii. Group number is same as the principal quantum number ‘n’ of the valence shell of the elements.
i. True
ii. False
Period number is same as the principal quantum number ‘n’ of the valence shell of the elements.

Question 30.
Name the following.
i. Shortest period in the modern periodic table.
ii. Block which is placed separately at the bottom of the modern periodic table.
i. First period
ii. f-Block

Question 31.
How can a period, group and block of the element be determined?
The group, period and the block of the element can be determined on the basis of its electronic configuration.
i. Period: The principal quantum number of the valence shell corresponds to the period of the element.
e. g. The principal quantum number (n) of the valence shell (3s1) of Na (1s2 2s2 2p6 3s1) is 3. This corresponds to third period.

ii. Block: The subshell in which the last electron enters, corresponds to the block of the elements (with exception being He).
e. g. The subshell 3d (in which the last electron enters) for Sc (1s2 2s2 2p6 3s2 3p6 3d1 4s2) corresponds to d block.

iii. Group: The group of the element is determined on the basis of number of electrons present in the outermost or penultimate [next to outermost, i.e. (n-1)] shell:

• For s-block elements, group number = number of valence electrons.
• For p-block elements, group number = 18 – number of electrons required to complete octet.
• For d-block elements, group number = 2 + number of (n-1)d electrons.

Question 32.
Outer electronic configurations of a few elements are given below. Explain them and identify the period, group and block in the periodic table to which they belong.
2He: 1s2, 54Xe: 5s25p6, 16S: 3s23p4, 79Au: 6s15d10
i. 2He: 1s2
Here, n = 1. Therefore, 2He belongs to the 1st period.
The shell n = 1 has only one subshell, namely 1s. The outer electronic configuration 1s2 of ‘He’ corresponds to the maximum capacity of 1s, the complete duplet. Therefore, He is placed at the end of the 1st period in the group 18 of inert gases. So, ‘He’ belongs to p-block.

ii. 54Xe: 5s25p6
Here, n = 5. Therefore, 54Xe belongs to the 5th period.
The outer electronic configuration. 5s25p6 corresponds to complete octet. Therefore, 54Xe is placed in group 18 and belongs to p-block.

iii. 16S: 3s23p4
Here, n = 3. Therefore, 16S belongs to the 3rd period. The 3p subshell in ‘S’ is partially filled and short of completion of octet by two electrons. Therefore, ‘S’ belongs to (18 – 2) = 16th group and p-block.

iv. 79AU: 6s15d10
Here n = 6. Therefore, ‘Au’ belongs to the 6th period.
The sixth period begins with filling of electron into 6s and then into 5d orbital.
The outer configuration of ‘Au’: 6s1 5d10 implies that (1 + 10) = 11 electrons are filled in the outer orbitals to give ‘Au’. Therefore ‘Au’ belongs to the group 11.
As the last electron has entered ‘d’ orbital ‘Au’ belongs to the d-block.

Question 33.
Predict the block, periods and groups to which the following elements belong.
i. Mg (Z = 12)
ii. V (Z = 23)
iii. Sb (Z = 51)
iv. Rn (Z = 86)
v. Na (Z = 11)
vi. Cl (Z = 17)
i. Mg (Z = 12): Atomic number of Mg is 12. Electronic configuration is 1s2 2s2 2p6 3s2.
Block: Since the last electron enters s subshell (3 s), Mg belongs to s-block.
Period: n = 3. Therefore, it is present in the third period.
Group: For s-block element, group number = number of valence electrons = 2. Hence, it belongs to group 2.

ii. V (Z = 23): Atomic number of V is 23. Electronic configuration is 1s2 2s2 2p6 3s2 3p6 3d3 4s2.
Block: Since the last electron enters d subshell (3d), V belongs to d-block.
Period: n = 4. Therefore, it is present in the fourth period.
Group: For d-block elements, group number = 2 + number of (n – 1)
d electrons = 2 + 3 = 5. Hence, it belongs to group 5.

iii. Sb (Z = 51): Atomic number of Sb is 51.
Electronic configuration is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p3.
Block: Since the last electron enters p subshell (5p), Sb belongs to p-block.
Period: n = 5. Therefore, it is present in the fifth period.
Group: For p block elements, group number = 18 – number of electrons required to complete octet
= 18 – 3 = 15. Hence it belongs to group 15.

iv. Rn (Z = 86): Atomic number of Rn is 86.
Electronic configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6.
Block: Since the last electron enters p subshell (6p), Rn belongs to p-block.
Period: n = 6. Therefore, it is present in the sixth period.
Group: For p block elements, group number = 18 – number of electrons required to complete octet
= 18 – 0 = 18. Hence, it belongs to group 18.

v. Na (Z = 11): Atomic number of Na is 11. Electronic configuration is 1s2 2s2 2p6 3s1.
Block: Since the last electron enters s subshell (3s), Na belongs to s-block.
Period: n = 3. Therefore, it is present in the third period.
Group: For s-block element, number of the group = number of valence electrons = 1. Hence, it belongs to group 1.

vi. Cl (Z = 17): Atomic number of Cl is 17. Electronic configuration is 1s2 2s2 2p6 3s2 3p5.
Block: Since the last electron enters p subshell (3p), Cl belongs to p-block.
Period: n = 3. Therefore, it is present in the third period.
Group: For p block elements, group number = 18 – number of electrons required to complete octet
= 18 – 1 = 17. Hence, it belongs to group 17.

Question 34.
State the characteristics of s-block elements.

• The s-block contains the elements of group 1 (alkali metals) and group 2 (alkaline earth metals).
• They occur in nature only in combined state as they are reactive elements.
• Except Li and Be, compounds formed by all other s-block elements are predominantly ionic in nature.
• This is because they have only one or two valence electrons which they can lose readily forming M+ or M2+ ions.
• Since they can lose electrons easily, they have low ionization enthalpies, which decreases down the group resulting in increased reactivity.

Question 35.
What are main group elements?
The p-block elements together with s-block elements are called main group elements or representative elements.

Question 36.
Give reason: Group 18 elements do not participate in chemical reactions readily.

• Group 18 is the last group of p-block and include noble or inert gases.
• They have closed valence shells (complete duplet in the case of ‘He’ and complete octet in the case of the other noble gases).
• Therefore, they show very low chemical reactivity and thus, do not participate in chemical reactions readily.

Question 37.
Why nonmetals present in group 17 and 16 in the modern periodic table are highly reactive?

• Nonmetals present in group 17 (halogen family) and group 16 (chalcogens) have highly negative electron gain enthalpies.
• As a result, they readily accept one or two electrons and form anions (X or X2-) that have complete octet.
• Therefore, nonmetals present in group 17 and 16 are highly reactive.

Question 38.
Explain the composition of the p-block in the modern periodic table.

• The p-block contains elements of groups 13 to 18.
• It contains all the three types of elements i.e., metals, nonmetals and metalloids.
• In the p-block, metals and nonmetals are separated from each other by a zig-zag line. The metals are present on the left and the nonmetals are present on the right side while the metalloids are present along the zig-zag line.

Question 39.
State whether the following statements are true or false. Correct if false.
i. Nonmetallic character increases from left to right across a period.
ii. Nonmetallic character increases down a group.
i. True
ii. False
Nonmetallic character decreases down a group.

Question 40.
Differentiate between s-block and p-block elements.
s-Block elements:

• s-Block contains group 1 and group 2 elements.
• It contains only metals.
• The last electron in the s-block elements enters in s orbital.
• General outer electronic configuration of s-block elements is ns1-2.
• e.g. Na, K, Ca, Mg, etc.

p-Block elements:

• p-Block contains elements from groups 13 to 18.
• It contains metals, nonmetals as well as metalloids.
• The last electron in the p-block elements enters in p orbital.
• General outer electronic configuration of p-block elements is ns2 np1-6.
• e.g. C, N, O, F, etc.

Question 41.
Write a note on the characteristics of the d-block elements.

• The d-block contains elements of the groups 3 to 12 which are all metals. They are also known as transition elements or transition metals.
• They form a bridge between chemically reactive s-block elements and less reactive elements of groups 13 and 14.
• Most of the d-block elements possess partially filled inner d orbitals. As a result, the d-block elements have properties such as variable oxidation state, paramagnetism, ability to form coloured ions. They can be used as catalysts.
• Zn, Cd, and Hg with configuration ns2 (n-1)d10, (completely filled s and d subshells) do not show characteristic properties of transition metals as they are stable.

Question 42.
Explain in brief about the f-block elements.

• The elements present in f-block are all metals and are placed in the two rows called lanthanide series (58Ce to 71Lu) and actinide series (90Th to 103Lr).
• The lanthanides are also known as rare earth elements while the actinide elements beyond 92U are called transuranium elements.
• The last electron of the elements of these series is filled in the (n-2)f subshell, and therefore, these are called inner transition elements.
• These elements have very similar properties within each series.

Question 43.
What is lanthanide and actinide series?
i. Lanthanide series: The fourteen elements after lanthanum (Z = 57) i.e., from cerium (Z = 58) to lutetium (Z = 71) are named after their preceding member (57La) present in the third group and 6th period and are called lanthanides. They are kept in separate series called lanthanide series at the bottom of the modem periodic table.

ii. Actinide series: The fourteen elements after actinium i.e., from thorium (Z = 90) to lawrencium (Z = 103) are named after 89Ac present in third period and 7th group. They are kept in separate series called actinide series at the bottom of the modem periodic table.

Question 44.
Differentiate between d-block and f-block elements.
d-Block elements:

• d-Block contains elements from group 3 to group 12.
• It is present in the middle of the modern periodic table.
• They are also known as transition elements.
• The last electron in the d-block elements enters in d orbital.
• General outer electronic configuration of d-block elements is ns0-2 (n-1)d1-10 .
• e.g. Cu, Zn, Cr, Ti, V, etc.

f-Block elements:

• f-Block contains elements of lanthanide and actinide series.
• f-block elements are present below the modern periodic table as two separate rows.
• They are also known as inner transition elements.
• The last electron in the f-block elements enters in f orbital.
• General outer electronic configuration of f-block elements is ns2 (n-1) d0-1 (n-2) f114.
• e.g. Ce, Pr, Nd Th, U, Np, etc.

Question 45.
Chlorides of two metals are common laboratory chemicals and both are colourless. One of the metals reacts vigorously with water while the other reacts slowly. Place the two metals in the appropriate block in the periodic table. Justify your answer.
i. Metals are present in all the four blocks of the periodic table.
ii. Salts of metals in the f-block and p-block (except AlCl3) are not common laboratory chemicals. Therefore, the choice is between s- and d-block.
iii. From the given properties their placement is done as shown below:

• s-block: Metal that reacts vigorously with water.
• d-block: Metal that reacts slowly with water.

iv. The colourless nature of the less reactive metal in the d-block implies that the inner d subshell is completely filled.

Question 46.
What are periodic properties?

• The elements in the modem periodic table (long form of periodic table) are arranged in such a way that on moving across a period or down the group, several properties of elements vary in regular fashion. These properties are called periodic properties.
• Atomic and ionic radii, ionization enthalpy, electron gain enthalpy, electronegativity, valency and oxidation states are several properties of elements that show periodic variations.

Question 47.
What leads to the phenomena called effective nuclear charge and screening effect in an atom?

• The periodic trends are explained in the terms of two fundamental factors, namely, attraction of extranuclear electrons towards the nucleus and repulsion between electrons belonging to the same atom.
• These attractive and repulsive forces operate simultaneously in an atom.
• This results in two interrelated phenomena called effective nuclear charge and screening effect in an atom.

Question 48.
Explain the concept of effective nuclear charge in detail.
i. In a multi-electron atom, the positively charged nucleus attracts the negatively charged electrons around it, and there is mutual repulsion between the negatively charged extranuclear electrons.
ii. The repulsion by inner shell electrons results in pushing the outer shell electrons further away from the nucleus. Thus, the outer shell electrons are held less tightly by the nucleus.
iii. As a result, the attraction of the nucleus for an outer electron is partially cancelled and hence, an outer shell electron does not experience the actual positive charge present on the nucleus. This effect of the inner electrons on the outer electrons is called screening effect or shielding effect.
iv. The net nuclear charge actually experienced by an electron is called the effective nuclear charge (Zeff).
The effective nuclear charge is lower than the actual nuclear charge (Z).
v. Effective nuclear charge (Zeff) = Z – electron shielding
= Z – σ
Here σ (sigma) is called shielding constant or screening constant and the value of σ depends upon type of the orbital that the electron occupies.

Question 49.
Define:
i. Effective nuclear charge (Zeff)
ii. Screening effect (or shielding effect)
i. Effective nuclear charge (Zeff): In multi-electron atom, the net nuclear charge actually experienced by an electron is called the effective nuclear charge (Zeff).
ii. Screening effect (or shielding effect): In multi-electron atom, the effect of the inner electrons on the outer electrons is called screening effect or shielding effect of the inner/core electrons.

Question 50.
Explain the variations in effective nuclear charge
i. Across a period
ii. Down a group
i. Across a period:

• As we move across a period, atomic number increases by one and thus, actual nuclear charge (Z) increases by +1 at a time.
• However, the valence shell remains the same and the newly added electron gets accommodated in the same shell. There is no addition of electrons to the core i.e., inner shells. Thus, shielding due to core electrons remains the same even though the actual nuclear charge increases.
• As a result, the effective nuclear charge (Zeff) goes on increasing across a period.

ii. Down a group:

• As we move down a group, a new larger valence shell is added. As a result, there is an additional shell in the core.
• The shielding effect of the increased number of core electrons outweighs the effect of the increased nuclear charge. Thus, the effective nuclear charge experienced by the outer electrons decreases largely down a group.
• Hence, the effective nuclear charge (Zeff) decreases down a group.

Question 51.
Atomic radius is one half of the internuclear distance between two adjacent atoms of a metal or two single bonded atoms of a nonmetal.

Question 52.
What is meant by covalent radius of the atom? Explain with suitable examples.

• In the case of nonmetals (except noble gases), the atoms of an element are bonded to each other by covalent bonds.
• Bond length of a single bond is taken as sum of radii of the two single bonded atoms. This is called covalent radius of the atom.
• For example: Bond length of C-C bond in diamond is 154 pm. Therefore, atomic radius of carbon is estimated to be 77 pm which is half of bond length ($$\frac {1}{2}$$ × 154 = 77).

Question 53.
How is atomic radius of a nonmetallic element estimated?

• The atomic size of a nonmetallic element is estimated from the distance between the two atoms bound together by a single covalent bond. From this, the covalent radius of the element is estimated.
• The internuclear distance in a diatomic molecule of an element is its covalent bond length. Half the covalent bond length gives the covalent radius.
• Bond length of Cl-Cl bond in Cl2 is measured as 198 pm. Therefore, the atomic radius of Cl is estimated to be 99 pm.

Question 54.
One half of the distance between the centres of nucleus of the two adjacent atoms of a metallic crystal is called as a metallic radius.

Question 55.
How is metallic radius determined in the case of metals? Give suitable example.

• In the case of metals, distance between the adjacent atoms in metallic sample is measured. One half of this distance is taken as the metallic radius.
• For example: In beryllium, distance between the adjacent Be atoms is measured. One half of this distance is taken as the metallic radius of a Be atom.
• Distance between two adjacent Be atoms is 224 pm. Therefore, metallic radius of a Be atom is 112 pm.

Note: Atomic radii of some elements are given in the table below.

Question 56.
How is a cation and an anion formed?
A cation (or positively charged ion) is formed by the removal of one or more electrons from the atom of an element whereas an anion (or negatively charged ion) is formed when the atom of an element gains one or more electrons.

Question 57.
Give reasons: Radius of a cation is smaller and that of an anion is larger as compared to that of their parent atoms.

• A cation is formed by the loss of one or more electrons, therefore, it contains fewer electrons that the parent atom but has the same nuclear charge.
• As a result, the shielding effect is less and effective nuclear charge is larger within a cation. Thus, radius of a cation is smaller than the parent atom.
• However, an anion is formed by the gain of one or more electrons and therefore, it contains a greater number of electrons than the parent atom.
• Due to these additional electrons, anion experiences increased electronic repulsion and decreased effective nuclear charge. As a result, an anion has larger radius than its parent atom.

Hence, radius of a cation is smaller and that of an anion are larger as compared to that of their parent atoms.

Question 58.
Define: Isoelectronic species
The atoms or ions which have the same number of electrons are called isoelectronic species.

Question 59.
Explain with example why the radii of isoelectronic species vary.
i. The radii of isoelectronic species vary according to actual nuclear charge. Larger nuclear charge exerts greater attraction on the electrons and thus, the radius of that isoelectronic species becomes smaller.
ii. For example, F and Na+ both have 10 electrons but the nuclear charge on F is +9 which is smaller than that of Na+ which has the nuclear charge +11.
Hence, F has larger ionic radii (133 pm) than Na+ (98 pm).

Question 60.
What is the trend observed in the ionic size of the following isoelectronic species? Explain.
i. Na+, Mg2+, Al3+ and Si4+
ii. O2-, F, Na+ and Mg2+
i. Na+, Mg2+, Al3+ and Si4+

a. Among the given ions, the nuclear charge varies but the number of electrons remains the same and therefore, these are isoelectronic species.
b. The radii of isoelectronic species vary according to actual nuclear charge. Larger nuclear charge exerts greater attraction on the electrons and thus, the radius of that isoelectronic species becomes smaller.
c. The nuclear charge increases in the order Na+ < Mg2+ < Al3+ < Si4+ and thus, the ionic size decreases in the order Na+ > Mg2+ > Al3+ > Si4+.

ii. O2-, F, Na+ and Mg2+

a. Among the given ions, the nuclear charge varies but the number of electrons remains the same and therefore, these are isoelectronic species.
b. The radii of isoelectronic species vary according to actual nuclear charge. Larger nuclear charge exerts greater attraction on the electrons and thus, the radius of that isoelectronic species becomes smaller.
c. The nuclear charge increases in the order O2- < F < Na+ < Mg2+ and thus, the ionic size decreases in the order O2- > F > Na+ > Mg2+.

Question 61.
Identify the species having larger radius from the following pairs:
i. Na and Na+
ii. Na+ and Mg2+
i. The nuclear charge is the same in Na and Na+. But Na+ has a smaller number of electrons and a smaller number of occupied shells (two shells in Na+, while three shells in Na). Therefore, radius of Na is larger.
ii. Na+ and Mg2+ are isoelectronic species. Mg2+ has a larger nuclear charge than that of Na+. Therefore, Na+ has larger radius.

Question 62.
Which of the following species will have the largest and the smallest size? Why?
Mg, Mg2+, Al, Al3+

• Atomic radius decreases across the period. Hence, the atomic radius of Mg is larger than that of Al.
• Parent atoms have larger radius than their corresponding cations. Hence, the radius of Mg is larger than that of Mg2+ and the radius of Al is larger than that of Al3+.
• Mg2+ and Al3+ are isoelectronic. Among isoelectronic species, the one with larger nuclear charge will have smaller radius. Al3+ (Z = 13) has a larger nuclear charge than that of Mg2+ (Z = 12). Hence, the ionic radius of Al3+ is smaller than Mg2+.
• Therefore, the decreasing order of radius is Mg > Al > Mg2+ > Al3+.

Hence, species with the largest size is Mg and with the smallest size is Al3+.

Question 63.
Identify the element with more negative value of electron gain enthalpy from the following pairs. Justify.
i. Cl and Br
ii. F and O
i. Cl and Br belong to the same group of halogens with Br having higher atomic number than CL As the atomic number increases down the group, the effective nuclear charge decreases. The increased shielding effect of core electrons can be noticed. The electron has to be added to a farther shell, which releases less energy and thus, electron gain enthalpy becomes less negative down the group. Therefore, Cl has more negative electron gain enthalpy than Br.

ii. F and O belong to the same second period with F having higher atomic number than O. As the atomic number increases across a period, atomic radius decreases, effective nuclear charge increases and electron can be added more easily. Therefore, more energy is released with gain of an electron as we move towards right in a period. Therefore, F has more negative electron gain enthalpy than O.

Question 64.
Explain the importance of electronegativity.

• When two atoms of different elements form a covalent bond, the electron pair is shared unequally.
• Electronegativity represents attractive force exerted by the nucleus on shared electrons. Electron sharing between covalently bonded atoms takes place using the valence electron.
• It depends upon the effective nuclear charge experienced by electron involved in formation of the covalent bond.
• Electronegativity predicts the nature of the bond, or, how strong is the force of attraction that holds two atoms together.

Question 65.
Explain the trend in electronegativity
i. across a period
ii. down a group
i. Across a period:
a. As we move across a period from left to right in the periodic table, the effective nuclear charge increases steadily.
b. Hence, due to the increase in effective nuclear charge, the tendency to attract shared electron pair in a covalent bond increases i.e., electronegativity increases from left to right across a period.
e. g. Li < Be < B < C < N < O <F.

ii. Down a group:
a. As we move down the group from top to bottom in the periodic table, the size of the valence shell goes on increasing.
b. However, the effective nuclear charge decreases as the shielding effect of the core electrons increases due to the increase in the size of the atoms.
c. Thus, the tendency to attract shared electron pair in a covalent bond decreases, decreasing the electronegativity down the group.
e.g. F > Cl > Br > I > At.

Question 66.
Explain the terms:
i. Valency of an element
ii. Oxidation state (or oxidation number)
iii. Chemical reactivity
i. Valency of an element:

• Valency of an element indicates the number of chemical bonds that the atom can form giving a molecule.
• The most fundamental chemical property of an element is its combining power. This property is numerically expressed in terms of valency or valence.
• Valence does not have any sign associated with it.
• Valency of the main group elements is usually equal to the number of valence electrons (outer electrons) and/or equal to difference between 8 and the number of valence electrons.

ii. Oxidation state (or oxidation number):

• The oxidation state or oxidation number is a frequently used term related to valence.
• Oxidation number has a sign, + or – which is decided by the electronegativities of atoms that are bonded.

iii. Chemical reactivity:

• Chemical reactivity is related to the ease with which an element loses or gains the electrons.
• Chemical properties of elements depend on their electronic configuration.

Question 67.
What is the trend observed in the valency of main group elements?
i. Valency of the main group elements is usually equal to the number of valence electrons (outer electrons) or it is equal to the difference between 8 and the number of valence electrons.
i.e., (8 – number of valence electrons).
ii. The valency remains the same down the group and shows a gradual variation across the period as atomic number increases from left to right.

Note: Periodic trends in valency of main group elements.

Question 68.
Give any two distinguishing points between metals and nonmetals.
Metals:

1. Generally, metals exhibit good electrical conductivity.
2. They can form compounds by loss of valence electrons.

Nonmetals:

1. Generally, nonmetals exhibit poor electrical conductivity.
2. Nonmetals can form compounds by gain of valence electrons in valence shell.

Question 69.
Explain the variation of the following property of elements down a group and across a period.
i. Metallic character
ii. Nonmetallic character
The variation observed in the metallic and nonmetallic character of elements can be explained in the terms of ionization enthalpy and electron gain enthalpy.
i. Metallic character:

• The ionization enthalpy decreases down the group. Thus, the tendency to lose valence electrons increases down the group and the metallic character increases down a group.
• However, the ionization enthalpy increases across the period and as a result metallic character decreases across a period.

ii. Nonmetallic character:

• Electron gain enthalpy becomes less negative as we move down the group and hence, nonmetallic character decreases down the group.
• However, electron gain enthalpy becomes more and more negative across the period and thus, nonmetallic character increases across the period.

Question 70.
Justify the position of most reactive and least reactive elements in the modern periodic table.

• Chemical reactivity of elements depends on the ease with which it attains electronic configuration of the nearest inert gas by gaining or losing electrons.
• The elements preceding an inert gas react by gaining electrons in the outermost shell, whereas the elements which follow an inert gas in the periodic table react by loss of valence electrons. Thus, the chemical reactivity is decided by the electron gain enthalpy and ionization enthalpy values, which in turn, are decided by effective nuclear charge and finally by the atomic size.
• The ionization enthalpy is the smallest for the element on the extreme left in a period, whereas the electron gain enthalpy is the most negative for the second last element on the extreme right, (preceding to the inert gas which is the last element of a period).
• Thus, the most reactive elements lie on the extreme left and the extreme right (excluding inert gases) of the periodic table.

Question 71.
How can we predict chemical reactivity of elements based on their oxide formation reactions and the nature of oxides formed?

• The chemical reactivity can be illustrated by comparing the reaction of elements with oxygen to form oxides and the nature of the oxides.
• Alkali metals present on the extreme left of the modem periodic table are highly reactive and thus, they react vigorously with oxygen to form oxides such as Na2O which reacts with water to form strong bases like NaOH.
• The reactive elements on the right i.e., halogens react with oxygen to form oxides such as Cl2O7 which on reaction with water form strong acids like HClO4.
• The oxides of the elements in the centre of the main group elements are either amphoteric (Al2O3) neutral (CO, NO) or weakly acidic (CO2).

Question 72.
Write the chemical equations for reaction, if any, of (i) Na2O and (ii) Al2O3 with HCl and NaOH both. Correlate this with the position of Na and Al in the periodic table, and infer whether the oxides are basic, acidic or amphoteric.
i. Na2O + 2HCl → 2NaCl + H2O
Na2O + NaOH → No reaction
As Na2O reacts with an acid to form salt and water it is a basic oxide. This is because Na is a reactive metal lying on the extreme left of the periodic table.

ii. Al2O3 + 6HCl → 2AlCl3 + 3H2O
Al2O3 + 2NaOH → 2NaAlO2 + H2O
As Al2O3 reacts with an acid as well as base to form a salt and water. It is an amphoteric oxide. Al is a moderately reactive element lying in the centre of main group elements in the periodic table.

Question 73.
Comment on the chemical reactivity of d-block and f-block elements.

• d-block (transition) elements and f-block (inner transition) elements exhibit very small change in atomic radii.
• Therefore, the transition and inner transition elements belonging to the individual series have similar chemical properties.
• Their ionization enthalpies are intermediate between those of s-block and p-block elements. Thus, d-block and f-block elements generally show moderate reactivity.

Question 74.
Ge, S and Br belong to the groups 14, 16 and 17, respectively. Predict the empirical formulae of the compounds those can be formed by (i) Ge and S, (ii) Ge and Br.
From the group number we understand that the general outer electronic configuration and number of valence electrons and valencies of the three elements are:

i. S is more electronegative than Ge. Therefore, the empirical formula of the compound formed by these two elements is predicted by the method of cross multiplication of the valencies:

ii. Br is more electronegative than Ge. The empirical formula of the compound formed by these two elements is predicted by the method of cross multiplication of valencies:

[Note: More electronegative element is written on right hand side in cross multiplication method.]

Question 75.
The first ionization enthalpies of 5 elements of second period are given below:

 Element 1st IE values (kJ mol-1) I 520 II 1681 III 1086 IV 2080 V 899

Based on the above data, answer the following questions:
i. Identify the element having highest atomic number.
ii. If element I is lithium, how will you explain its low value of first ionization enthalpy?
iii. Explain why ionization enthalpies are always positive.
i. Element IV. The first ionization enthalpy increases with increase in atomic number along a period. Hence, the element IV having highest IE will have highest atomic number among the given elements.
ii. Alkali metals have only one electron in their valence shell which can be easily lost resulting in the stable noble gas configuration. Therefore, lithium shows low value of first ionization enthalpy.
iii. Energy is always required to remove electrons from an atom. Hence, ionization enthalpies have positive value.

Question 76.
From the elements Mg, Ar, Cl, Sr, P and S, choose one that fits each of the below given descriptions:
i. An element having two valence electrons.
ii. An element having properties similar to that of O.
iii. A noble gas.
iv. An alkaline earth metal,
v. An element having electronic configuration 1s22s22p63s23p3.
i. Magnesium (Mg)
ii. Sulphur (S)
iii. Argon (Ar)
iv. Strontium (Sr)
v. Phosphorus (P)

Multiple Choice Questions

1. Mendeleev’s periodic table had …………… elements.
(A) 75
(B) 83
(C) 63
(D) 118
(C) 63

2. The serial or ordinal number of an element in Mendeleev’s periodic table was recognized as ………….
(A) neutron number
(B) valency
(C) principal quantum number
(D) proton number
(D) proton number

3. Mendeleev predicted the existence of …………..
(A) aluminium
(B) silicon
(C) tellurium
(D) germanium
(D) germanium

4. According to Mendeleev’s periodic law, the physical and chemical properties of elements are the periodic function of their …………..
(A) atomic weights
(B) atomic numbers
(C) molecular formulas
(D) molecular weights
(A) atomic weights

5. Moseley showed that the fundamental property of an element is ……………
(A) atomic number
(B) atomic mass
(C) both A and B
(D) none of these
(A) atomic number

6. According to periodic law of elements, the variation in properties of elements is related to their ……………
(A) densities
(B) atomic masses
(C) atomic sizes
(D) atomic numbers
(D) atomic numbers

7. At present, how many elements are known?
(A) 118
(B) 110
(C) 114
(D) 120
(A) 118

8. The long form of the periodic table consists of how many periods?
(A) 5
(B) 8
(C) 10
(D) 7
(D) 7

9. According to quantum mechanical model of the atom, the properties of elements can be correlated to their …………….
(A) atomic number
(B) atomic mass
(C) valency
(D) electronic configuration
(D) electronic configuration

10. The fourth, fifth and sixth periods are long periods and contain ……………
(A) 18, 18 and 36
(B) 18, 28 and 32
(C) 18, 15 and 31
(D) 18, 18 and 32
(D) 18, 18 and 32

11. f-block elements are also known as ……………
(A) transition elements
(B) inert gas elements
(C) normal elements
(D) inner transition elements
(D) inner transition elements

12. Which of the following forms a bridge between reactive s-block elements and less reactive group 13 and 14 elements?
(A) Inert gases
(B) Transition metals
(C) Halogens
(D) Inner transition metals
(B) Transition metals

13. ………… elements are known as chalcogens.
(A) Group 17
(B) Group 18
(C) Group 16
(D) Group 1
(C) Group 16

14. The name ‘rare earth elements’ is used for …………..
(A) lanthanides only
(B) actinides only
(C) both lanthanides and actinides
(D) alkaline earth metals
(C) both lanthanides and actinides

15. Atomic number of V is 23 and its electronic configuration is …………….
(A) 1s2 2s2 2p6 3p6 3d3 4s2
(B) 1s2 2s2 2d3 3p6 2p6 4s2
(C) 2s2 1s2 2p6 3s2 3d3 4s2
(D) 1s2 2s2 2p6 3s2 3p6 3d3 4s2
(D) 1s2 2s2 2p6 3s2 3p6 3d3 4s2

16. Aluminium belongs to …………. elements.
(A) s-block
(B) p-block
(C) d-block
(D) f-block
(B) p-block

17. In P3-, S2- and Cl ions, the increasing order of size is ………….
(A) Cl < S2- < P3-
(B) P3- < S2- < Cl
(C) S2- < Cl < P3-
(D) S2- < P3- < Cl
(A) Cl- < S2- < P3-

18. The CORRECT order of radii is ……………
(A) N < Be < B
(B) F< O2- <N3-
(C) Na < Li < K
(D) Fe3+ < Fe2+ < Fe4+
(B) F < O2- <N3-

19. Which of the following species will have the largest size Mg, Mg2+, Fe, Fe3+?
(A) Mg
(B) Mg2+
(C) Fe
(D) Fe3+
(C) Fe

20. Which one of the following is CORRECT order of the size?
(A) I > I >I+
(B) I > I+ > I
(C) I+ > I > I
(D) I > I > I+
(D) I > I > I+

21. The CORRECT order of increasing radii of the elements Na, Si, Al and P is ……………
(A) Si < Al < P < Na
(B) Al < Si < P < Na
(C) P < Si < Al < Na
(D) Al < P < Si < Na
(C) P < Si < Al < Na

22. The metallic and nonmetallic properties of elements can be judged by their ……………
(A) electron gain enthalpy
(B) ionization enthalpy
(C) electronegativity
(D) valence
(C) electronegativity

23. Which element has the most negative electron gain enthalpy?
(A) Sulphur
(B) Fluorine
(C) Chlorine
(D) Hydrogen
(C) Chlorine

24. Which of the properties remain unchanged on descending a group in the periodic table?
(A) Atomic size
(B) Density
(C) Valency electrons
(D) Metallic character
(C) Valency electrons

## Maharashtra Board Class 11 Biology Important Questions Chapter 13 Respiration and Energy Transfer

Balbharti Maharashtra State Board 11th Biology Important Questions Chapter 13 Respiration and Energy Transfer Important Questions and Answers.

## Maharashtra State Board 11th Biology Important Questions Chapter 13 Respiration and Energy Transfer

Question 1.
What is Phosphorylation?
It is the formation of ATP, by addition inorganic phosphate to ADP.

Question 2.
What are the different ways of Phosphorylation?
Phosphorylation occurs in three different ways as – photophosphorylation, substrate-level phosphorylation and oxidative phosphorylation.

Question 3.
What is Substrate-level phosphorylation? Where does it occur?
Substrate-level phosphorylation is a direct phosphorylation of ADP by transfer of a phosphate group from any suitable substrate. It occurs in cytoplasm of the cells and matrix of mitochondria.

Question 4.
What is oxidative phosphorylation? Mention the site of this reaction.
In oxidative phosphorylation ATP is synthesize by using the energy released during the oxidation of substrates like NADH + H+ and FADH2. This occurs on the inner mitochondrial membrane only.

Question 5.
When is ATP hydrolysed?
ATP is hydrolysed whenever energy is required for any metabolic reactions.

Question 6.
What is respiration?
Respiration is a catabolic process wherein complex organic substrate is oxidized to simple components to generate biological energy, i.e. ATP.

Question 7.
Give an example for anabolic and catabolic process.
Anabolic process- Photosynthesis (Biosynthetic process).
Caiabolic process- Respiration (Breakdown process).

Question 8.
Name the following.

1. The substrate that undergoes oxidation during oxidative phosphorylation
2. The phosphorylation that occurs only in inner mitochondria! membrane
3. Two ways of cellular respiration

2. Oxidative phosphorylation
3. Anaerobic and aerobic respiration

Question 9.
What is anaerobic respiration?
1. Anaerobic respiration is the cellular respiration that does not involve the atmospheric oxygen. It is also called as fermentation.
2. It involves glycolysis where the product of glycolysis i.e. pyruvate is converted to either lactic acid or ethanol.

Question 10.
What is glycolysis? Describe various steps involved in glycolysis.
OR
Describe the process involved in formation of pyruvic acid from glucose molecule.
OR
What is glycolysis? Describe the process of glycolysis with the help of schematic representation.
Glycolysis is a process where glucose is broken down into two molecules of pyruvic acid, hence called glycolysis (glucose-breaking). It is common to both aerobic and anaerobic respiration. It occurs in the cytoplasm of the cell. It involves ten steps.
Glycolysis consists of two major phases:
1. Preparatory phase (1-5 steps).
2. Payoff phase (6-10 steps).
1. Preparatory phase:
a. In this phase, glucose is phosphorylated twice by using two ATP molecules and a molecule of fructose 1,6-bisphosphate is formed.
b. It is then cleaved into two molecules of glyceraldehyde-3-phosphate and dihydroxy acetone phosphate. These two molecules are 3-carbon carbohydrates (trioses) and are isomers of each other.
c. Dihydroxy acetone phosphate is isomerised to second molecule of glyceraldehyde-3-phosphate.
d. Therefore, two molecules of glyceraldehyde-3- phosphate are formed.
e. Preparatory phase of glycolysis ends.

2. Payoff phase:
a. In this phase, both molecules of glyceraldehyde-3-phosphate are converted to two molecules of 1,3- bisphoglycerate by oxidation and phosphorylation. Here, the phosphorylation is brought about by inorganic phosphate instead of ATP.
b. Both molecules of 1, 3-bisphosphoglycerate are converted into two molecules of pyruvic acid through series of reactions accompanied with release of energy. This released energy is used to produce ATP (4 molecules) by substrate-level phosphorylation.

Question 11.
Write down the overall chemical reaction of a process in which glucose in broken down to two molecules of pyruvic acid.
Overall reaction of glycolysis:
Glucose + 2 ATP + 2iP + 4 ADP + 2 NAD+ → 2 Pyruvate + 2 ADP + 4 ATP + 2 NADH + 2 Ha+ + 2 H2O

Question 12.
Write explanatorv notes on: Glycolysis
Glycolysis is a process where glucose is broken down into two molecules of pyruvic acid, hence called glycolysis (glucose-breaking). It is common to both aerobic and anaerobic respiration. It occurs in the cytoplasm of the cell. It involves ten steps.
Glycolysis consists of two major phases:
1. Preparatory phase (1-5 steps).
2. Payoff phase (6-10 steps).
1. Preparatory phase:
a. In this phase, glucose is phosphorylated twice by using two ATP molecules and a molecule of fructose 1,6-bisphosphate is formed.
b. It is then cleaved into two molecules of glyceraldehyde-3-phosphate and dihydroxy acetone phosphate. These two molecules are 3-carbon carbohydrates (trioses) and are isomers of each other.
c. Dihydroxy acetone phosphate is isomerised to second molecule of glyceraldehyde-3-phosphate.
d. Therefore, two molecules of glyceraldehyde-3- phosphate are formed.
e. Preparatory phase of glycolysis ends.

2. Payoff phase:
a. In this phase, both molecules of glyceraldehyde-3-phosphate are converted to two molecules of 1,3- bisphoglycerate by oxidation and phosphorylation. Here, the phosphorylation is brought about by inorganic phosphate instead of ATP.
b. Both molecules of 1, 3-bisphosphoglycerate are converted into two molecules of pyruvic acid through series of reactions accompanied with release of energy. This released energy is used to produce ATP (4 molecules) by substrate-level phosphorylation.

Question 13.
How glycolysis is regulated?
Glycolysis is strongly regulated by the complex interplay between ATP consumption, NADH2 regeneration and regulation of various glycolytic enzymes like hexokinase, PFK-1, pyruvate kinase, etc. Besides, it is also controlled by hormones like glucagon, epinephrine and insulin.

Question 14.
Where does glycolysis take place in a cell?
Glycolysis takes place in the cytoplasm of a cell.

Question 15.
What are the products of cleavage in glycolysis?
Dihydroxyacetone phosphate (DHAP) and 3-phosphoglyceraldehyde (3-PGAL) are the products of cleavage in glycolysis.

Question 16.
Where does dehydration occur in glycolysis?
In glycolysis, dehydration occurs when 2-Phosphoglyceric acid loses a water molecule (dehydration) to form phosphoenol pyruvic acid in presence of the enzyme enolase.

Question 17.
Name the process which is common to both aerobic and anaerobic respiration.
Glycolysis is common to both aerobic and anaerobic respiration.

Question 18.
Name the enzymes that catalyse the irreversible reactions.
Hexokinase, Phosphoffuctokinase, Phosphoglycerate kinase and Pyruvate kinase are the enzymes that catalyse the irreversible reactions.

Question 19.
Where glycolysis is the only source of energy production?
Glycolysis is only source of energy production in erythrocytes, renal medulla, brain and sperm.

Question 20.
Which type of muscle fibres are rich in myoglobin?
Red muscles are rich in myoglobin.

Question 21.
Which type of muscle fibre mainly performs anaerobic respiration?
White muscle fibres mainly performs anaerobic respiration.

Question 22.
What is lactic acid fermentation?
It is a process of anaerobic respiration where the pyruvic acid undergoes reduction by addition of one proton and two electrons donated by NADH+H+ to form lactic acid as the product and NAD+ as the byproduct of oxidation. Skeletal muscles usually derive energy by this process. It is represented as follows:

Question 23.
What is the fate of pyruvate in yeast?
Yeast shows both aerobic and anaerobic respiration depending upon the presence or absence of oxygen.
1. In absence of oxygen, the pyruvate undergoes anaerobic respiration where it is decarboxylated to acetaldehyde. The acetaldehyde is then reduced by NADH+H to ethanol and carbon dioxide. This type of anaerobic respiration is termed alcoholic fermentation.
2. In the presence of oxygen however, it can respire aerobically to produce C02 and H20.

Question 24.
What is alcoholic fermentation?
Alcoholic fermentation is a type of anaerobic respiration where the pyruvate is decarboxylated to acetaldehyde. The acetaldehyde is then reduced by NADH+H+ to ethanol and Carbon dioxide. Since ethanol is produced during the process, it is termed alcoholic fermentation. It is represented as follows:

Question 25.
Name the process of respiration which does not involve intake of oxygen (02) and release of carbon dioxide (C02).
Lactic acid fermentation is the process of anaerobic respiration which does not involve intake of oxygen (02) and release of carbon dioxide (C02).

Question 26.
Why yeast stops multiplying in the culture after alcoholic fermentation?
After alcoholic fermentation the multiplication of yeast stops because the alcohol formed during the process kills the yeast cells.

Question 27.
What is aerobic respiration?

1. Aerobic respiration occurs in the presence of free molecular oxygen during oxidation of glucose.
2. In this type of respiration, the glucose is completely oxidized to C02 and H20 with release of large amount of energy.
3. It involves glycolysis, acetyl CoA formation (connecting link reaction), Krebs cycle, electron transfer chain reaction and terminal oxidation.

Question 28.
Where does aerobic respiration occur in eukaryotic cell?
Aerobic respiration occurs in the mitochondria in eukaryotes.

Question 29.
Explain the conversion of pyruvic acid to acetyl CoA.
OR
Describe the connecting link between glycolysis and Krebs cycle.

1. The conversion of pyruvic acid to acetyl CoA is an oxidative decarboxylation reaction.
2. It is catalyzed by a multienzyme complex-pyruvate dehydrogenase complex (PDH). This enzyme is present in mitochondria of eukaryotes and cytosol of prokaryotes.
3. This reaction is called as ‘connecting link’ reaction between glycolysis and Krebs cycle.

Question 30.
Name the following.
1. Which enzymes converts pyruvic acid to acetyl CoA?
2. Name the coenzyme required by pyruvate dehydrogenase.
1. Pyruvate dehydrogenase
2. Thiamin (vitamin Bi)

Question 31.
Why is acetyl Co-A called connecting link between glycolysis and Krebs cycle?

1. The conversion of pyruvic acid to acetyl CoA is an oxidative decarboxylation reaction.
2. It is catalyzed by a multienzyme complex-pyruvate dehydrogenase complex (PDH). This enzyme is present in mitochondria of eukaryotes and cytosol of prokaryotes.
3. This reaction is called as ‘connecting link’ reaction between glycolysis and Krebs cycle.

Question 32.
Why vitamin Bi is important for maintaining good health?
1. Pyruvate dehydrogenase (PDH) requires thiamin (vitamin Bi) as a co-enzyme. It cannot function in absence of vitamin B1.
2. Thiamin deficiency causes many disorders such as pyruvic acidosis and lactic acidosis, which are life threatening conditions. Hence, it is required to maintain good health.

Question 33.
Describe Citric acid cycle.
OR
With the help of schematic representation explain Krebs cycle.

1. Krebs cycle or citric acid cycle is the second phase of aerobic respiration which takes place in the matrix of the mitochondria.
2. The acetyl CoA formed during the link reaction undergoes aerobic oxidation.
3. This cycle serves a common oxidative pathway for carbohydrates, fats and proteins.
4. In mitochondria pyruvic acid is decarboxylated and the remaining 2-carbon fragment is combined with a molecule of coenzyme A to form acetyl-CoA.
5. This reaction is an oxidative decarboxylation process and produces H+ ions and electrons along with carbon dioxide.
7. P-oxidation of fatty acids also produces acetyl-CoA as the end product.
8. Acetyl-CoA from both sources is condensed with oxaloacetic acid to form citric acid. Citric acid is oxidized step-wise by mitochondrial enzymes, releasing carbon dioxide.
9. Regeneration of oxaloacetic acid occurs to complete the cycle.
10. There are four steps of oxidation in this cycle, catalyzed by dehydrogenases (oxidoreductases) using NAD+ or FAD+ as the coenzyme.
11. The coenzymes are consequently reduced to NADH+H+ and FADH2 respectively. These transfer their electrons to the mitochondrial respiratory chain to get reoxidised.
12. One molecule of GTP (ATP) is also generated for every molecule of citric acid oxidized.

Question 34.
What is the site of Krebs cycle in mitochondria?
Krebs cycle takes place in the mitochondrial matrix.

Question 35.
Match the following:

 Column I Column II Column III 1. Krebs cycle (a) 1,3-Bisphosphoglycerate → 3-Phosphoglycerate (p) Pyruvate dehydrogenase 2. Glycolysis (b) Succinyl CoA → Succinate (q) NADH dehydrogenase 3. ETS (c) Pyruvic acid → Acetyl CoA (r) Two ATP are produced 4. Link reaction (d) Transfer of electrons from Complex to Ubiquinone (s) Succinyl CoA – synthetase

 Column I Column II Column III 1. Krebs cycle (b) Succinyl CoA → Succinate (s) Succinyl CoA – synthetase 2. Glycolysis (a) 1,3-Bisphosphoglycerate → 3-Phosphoglycerate (r) Two ATP are produced 3. ETS (d) Transfer of electrons from Complex I to Ubiquinone (q) NADH dehydrogenase 4. Link reaction (c) Pyruvic acid → Acetyl CoA (p) Pyruvate dehydrogenase

Question 36.
Explain ETS.
OR
Illustrate the mechanism of electron transport system.
OR
Give an account of ATP generation steps during ETS.
OR
Explain the mechanism of electron transportation system (ETS).
OR
Explain terminal oxidation.

1. NADH2 and FADH2 produced during glycolysis, connecting link reaction and Krebs cycle are oxidized with the help of various electron carriers and enzymes.
2. These carriers and enzymes are arranged on inner mitochondrial membrane in the form of various complexes as complex I, II, III, VI and V.
3. NADH+H+ is oxidised by NADH dehydrogenase (complex I) and it’s electrons are transferred to ubiquinone (coenzyme Q-CoQ) present on inner membrane of mitochondria. Reduced ubiquinone is called as ubiqunol.
4. FADH2 is oxidised by complex II (Succinate dehydrogenase) and these electrons are also transferred to CoQ.
5. The open end of the glass tube (delivery tube) is dipped into lime water containing in a test tube (Tube B).
6. Stoppers of both the tubes are fitted tightly to prevent leakage of gases. First test tube is placed in warm water (37° C-38° C) in a beaker.
7. Lime water gradually turns milky, indicating the evolution of carbon dioxide from the yeast preparation.
8. Level of the lime water in the delivery tube does not rise, showing that there is no decline in volume of gas in test tube A and consequently no utilization of oxygen by yeast. Preparation is stored for a day or two.
9. When we open the stopper of tube A we will notice a smell of alcohol indicating the formation of ethanol.
10. From this activity it may be inferred that yeast respires anaerobically to ferment glucose to ethanol and carbon dioxide.

Question 37.
Explain the significance of electron transport system.
Significance of ETS:

1. Major amount of energy is generated through ETS or terminal oxidation in the form of ATP molecules.
2. Per glucose molecule 38 ATP molecules are formed, out of which 34 ATP molecules are produced through ETS.
4. In this process, energy is released in a controlled and stepwise manner to prevent any damage to the cell.
5. ETS produces water molecules.

Question 38.
What is oxidative phosphorylation?
Oxidative phosphorylation: It is a metabolic pathway that uses energy released by the oxidation of substrates to produce ATP.

1. Oxidative phosphorylation takes place in the mitochondrial membrane.
2. Many intermediate products during respiration are oxidised and release 2H+.
4. Electrons pass through electron transport system to produce ATP and metabolic water.

Question 39.
Give the balance sheet of ATP formed in aerobic respiration.

 Step of Respiration Consumption Production Total Net benefit Substrate level phosphorylation 1 Oxidative Phosphorylation NADH+ H+ FADH2 Total Glycolysis 2 4 2 × 3 = 6 ___________ 6 10 8 Pyruvate → AcetylCoA _______________ ___________ 2 × 3 = 6 ___________ 6 6 6 Krebs cycle _______________ 1 × 2 = 2 6 × 3 = 18 2×2 = 4 22 24 24 Total 2 [6] 30 + 4 = [34] m 38

Question 40.
With the help of an experiment explain how yeast respires anaerobically.
Respiration in yeast can be demonstrated with the help of an experiment.
Anaerobic respiration in yeast:

1. A pinch of dry baker’s yeast suspended in water containing 10ml of 10% glucose in a test tube (test tube A).
2. The surface of the liquid is covered with oil to prevent entry of air and the test tube is closed tightly with rubber stopper to prevent leakage.
3. One end of a short-bent glass tube is inserted through it to reach the air inside the tube.
4. Other end of the glass tube is connected by a polyethylene or rubber tubing to another bent glass tube fitted into a stopper.
5. The open end of the glass tube (delivery tube) is dipped into lime water containing in a test tube
(Tube B).
6. Stoppers of both the tubes are fitted tightly to prevent leakage of gases. First test tube is placed in warm water (37° C-38° C) in a beaker.
7. Lime water gradually turns milky, indicating the evolution of carbon dioxide from the yeast preparation.
8. Level of the lime water in the delivery tube does not rise, showing that there is no decline in volume of gas in test tube A and consequently no utilization of oxygen by yeast. Preparation is stored for a day or two.
9. When we open the stopper of tube A we will notice a smell of alcohol indicating the formation of ethanol.
10. From this activity it may be inferred that yeast respires anaerobically to ferment glucose to ethanol and carbon dioxide.

Question 41.
With the help of an experiment explain how germinating seeds respire.

1. Seed coats of a few germinating seeds (peas, beans or gram) are removed and are then put in a test tube filled with mercury.
2. After closing the test tube with the thumb, it is vertically inverted in a trough of mercury and the thumb is carefully removed.
3. Being lighter than mercury, the seeds rise to the closed upper end of the test Uibe. No gas is seen at first in the test tube.
4. As germination proceeds, a gas begins to collect at the top of the mercury in the test tube.
5. On introducing a pellet of potassium hydroxide into the tube, it rises to the top and absorbs the gas. The mercury again fills the tube.
6. The potassium hydroxide reacts with carbon dioxide gas to produce potassium carbonate and water.
7. The gas therefore disappears. Evidently germinating seeds produce carbon dioxide by anaerobic respiration in the absence of oxygen in the mercury column.

[Note: Mercury is toxic chemical. Proper precautions must be taken while performing this experiment ]
[Note: Students can scan the adjacent QR code to get conceptual clarity with the aid of a relevant example.]

Question 42.
Give the significance of respiration.
OR
Write a short note on significance of respiration.

1. Respiration provides energy for biosynthesis of biomolecules.
2. It is also a source of energy for cell division, growth, repairs and replacement of worn out parts, movements,
locomotion etc.
3. Various intermediates of Krebs cycle are used as building blocks for synthesis of other complex compounds.
4. Coupled with photosynthesis, it helps to maintain the balance between C02 and O2 in the atmosphere.
5. Anaerobic respiration (fermentation) is used in various industries such as dairies, bakeries, distilleries, leather industries, paper industries etc. It is used in the commercial production of alcohol, organic acids, vitamins, antibiotics etc.

Question 43.
Match the following:

 Column I Column II Column III 1. Krebs cycle (a) 1,3-Bisphosphoglycerate → 3-Phosphoglycerate (p) Pyruvate dehydrogenase 2. Glycolysis (b) Succinyl CoA → Succinate (q) NADH dehydrogenase 3. ETS (c) Pyruvic acid → Acetyl CoA (r) Two ATP are produced 4. Link reaction (d) Transfer of electrons from Complex I to Ubiquinone (s) Succinyl CoA – synthetase

 Column I Column II Column III 1. Krebs cycle (b) Succinyl CoA → Succinate (s) Succinyl CoA – synthetase 2. Glycolysis (a) 1,3-Bisphosphoglycerate → 3-Phosphoglycerate (r) Two ATP are produced 3. ETS (d) Transfer of electrons from Complex I to Ubiquinone (q) NADH dehydrogenase 4. Link reaction (c) Pyruvic acid → Acetyl CoA (p) Pyruvate dehydrogenase

Question 44.

Question 1.
While teaching respiration professor said that oxygen is important for respiration in humans, Rakesh kept thinking, where exactly oxygen is required during cellular respiration? What would be the correct explanation for his doubt?
Oxygen is very important for life, we humans cannot survive without oxygen. Glycolysis, link reaction and Krebs cycle do not involve oxygen. In cellular reaction, oxygen is required only during ETS where it acts as an electron acceptor hence leading to terminal oxidation where it gets converted into water called metabolic water.

The process of respiration is very fast and occurs continuously as cell require continuous supply of energy to carry out metabolic activities, thus, we require oxygen for cellular respiration even when we are sleeping.

Question 2.
Sonal while studying ETS had a doubt, why FADH2 yields only 2 ATP’s whereas NADH2 yields three ATP’s? What would be the correct explanation for her doubt?

2. During this conversion, hydrogen is removed, which latter forms proton and electron. This electron so formed is passed on to different electron carriers. During this transfer of electron, energy is released which is used in ATP synthesis.
3. In case of NADH2, energy is released at three places hence results into formation of 3 ATPs whereas, in case of FADH2 energy is released at only two places, hence results into formation of only 2 ATPs.
4. Here, the ATP formation occurs by Chemiosmotic hypothesis.

Question 45.
Quick Review

Various steps involved in glycolysis:

 Step(s) Substrate Enzyme End product(s) Phosphorylation Glucose + ATP Hexokinase Glucose – 6 – Phosphate + ADP Isomerisation Glucose – 6-Phosphate Phosphohexose isomerase Fructose – 6 – Phosphate Phosphorylation Fructose – 6-Phosphate + ATP (Phosphate donor) Phosphofructokinase Fructose 1,6-Diphosphate + ADP Cleavage Fructose -1, 6-Diphosphate Aldolase 3 – Phosphoglyceraldehyde + Dihydroxyacetone phosphate Phosphorylation and Dehydrogenation 3-PGAL + H3PO4 + NAD+ Triosephosphate dehydrogenase 1, 3 Diphosphoglyceric acid + NADH + H+ Dephosphorylation 1, 3-DPGA + ADP Diphosphoglycerate kinase (Mg2) ATP + 3-Phosphoglyceric acid Rearrangement 3-PGA Phosphoglycerate mutase 2-Phosphoglyceric acid Dehydration 2-PGA Enolase Phosphoenol Pyruvic acid + H20 Dephosphorylation Phosphoenol Pyruvic acid +ADP Pyruvate kinase Pyruvic acid + ATP

Various steps involved in Krebs cycle:

 Step(s) Substrate Enzyme End product(s) Condensation Acetyl-CoA+Oxalo- acetic acid + H20 Citrate synthase Citric acid (6C) + Coenzyme- A Dehydration Hydration It is again completed in two steps: Citric acid Cis-Aconitic acid + H20 Aconitase Aconitase Cis-Aconitic acid + H20 Iso-citric acid(6C) Oxidative decarboxylation a. Isocitric acid + NAD+ Isocitrate dehydrogenase Oxalo succinic acid(6C) + NADH + H+ b. Oxalosuccinic acid Isocitrate dehydrogenase a – ketoglutaric acid(5C) + CO Oxidative Decarboxylation. (-2H) (-C02) a-Ketoglutaric acid + H20 + NAD + Coenzyme A a-Ketoglutarate dehydrogenase complex Succinyl-CoA(4C) + NADH + H++co2 Substrate level phosphorylation Succinyl – Co A + GDP + iP Succinyl CoA synthetase Succinic acid (4C) + Coenzyme-A + GTP Dehydrogenation (-2H) Succinic acid + FAD (H-acceptor) Succinate dehydrogenase Fumaric acid (4C) + FADH2 Hydration(+H20) Fumaric acid + H20 Hydration(+H20) Fumaric acid + H20 Dehydrogenation (-2H) Malic acid + NAD+ (H-acceptor) Dehydrogenation (-2H) Malic acid + NAD+ (H-acceptor)

Question 46.
Exercise

Question 1.
Define phosphorylation.
It is the formation of ATP, by addition inorganic phosphate to ADP.

Question 2.
Mention the different ways of phosphorylation.
Phosphorylation occurs in three different ways as – photophosphorylation, substrate-level phosphorylation and oxidative phosphorylation.

Question 3.
Define substrate-level phosphorylation.
Substrate-level phosphorylation is a direct phosphorylation of ADP by transfer of a phosphate group from any suitable substrate. It occurs in cytoplasm of the cells and matrix of mitochondria.

Question 4.
What is fermentation?
1. Anaerobic respiration is the cellular respiration that does not involve the atmospheric oxygen. It is also called as fermentation.
2. It involves glycolysis where the product of glycolysis i.e. pyruvate is converted to either lactic acid or ethanol.

Question 5.
Where does glycolysis occurs?
Glycolysis is a process where glucose is broken down into two molecules of pyruvic acid, hence called glycolysis (glucose-breaking). It is common to both aerobic and anaerobic respiration. It occurs in the cytoplasm of the cell. It involves ten steps.
Glycolysis consists of two major phases:
1. Preparatory phase (1-5 steps).
2. Payoff phase (6-10 steps).
1. Preparatory phase:
a. In this phase, glucose is phosphorylated twice by using two ATP molecules and a molecule of fructose 1,6-bisphosphate is formed.
b. It is then cleaved into two molecules of glyceraldehyde-3-phosphate and dihydroxy acetone phosphate. These two molecules are 3-carbon carbohydrates (trioses) and are isomers of each other.
c. Dihydroxy acetone phosphate is isomerised to second molecule of glyceraldehyde-3-phosphate.
d. Therefore, two molecules of glyceraldehyde-3- phosphate are formed.
e. Preparatory phase of glycolysis ends.

2. Payoff phase:
a. In this phase, both molecules of glyceraldehyde-3-phosphate are converted to two molecules of 1,3- bisphoglycerate by oxidation and phosphorylation. Here, the phosphorylation is brought about by inorganic phosphate instead of ATP.
b. Both molecules of 1, 3-bisphosphoglycerate are converted into two molecules of pyruvic acid through series of reactions accompanied with release of energy. This released energy is used to produce ATP (4 molecules) by substrate-level phosphorylation.

Question 6.
What is glycolysis? Explain with the help of schematic representation.
Glycolysis is a process where glucose is broken down into two molecules of pyruvic acid, hence called glycolysis (glucose-breaking). It is common to both aerobic and anaerobic respiration. It occurs in the cytoplasm of the cell. It involves ten steps.
Glycolysis consists of two major phases:
1. Preparatory phase (1-5 steps).
2. Payoff phase (6-10 steps).
1. Preparatory phase:
a. In this phase, glucose is phosphorylated twice by using two ATP molecules and a molecule of fructose 1,6-bisphosphate is formed.
b. It is then cleaved into two molecules of glyceraldehyde-3-phosphate and dihydroxy acetone phosphate. These two molecules are 3-carbon carbohydrates (trioses) and are isomers of each other.
c. Dihydroxy acetone phosphate is isomerised to second molecule of glyceraldehyde-3-phosphate.
d. Therefore, two molecules of glyceraldehyde-3- phosphate are formed.
e. Preparatory phase of glycolysis ends.

2. Payoff phase:
a. In this phase, both molecules of glyceraldehyde-3-phosphate are converted to two molecules of 1,3- bisphoglycerate by oxidation and phosphorylation. Here, the phosphorylation is brought about by inorganic phosphate instead of ATP.
b. Both molecules of 1, 3-bisphosphoglycerate are converted into two molecules of pyruvic acid through series of reactions accompanied with release of energy. This released energy is used to produce ATP (4 molecules) by substrate-level phosphorylation.

Question 7.
Define fermentation. What are the different types of fermentation?
1. Anaerobic respiration is the cellular respiration that does not involve the atmospheric oxygen. It is also called as fermentation.
2. It involves glycolysis where the product of glycolysis i.e. pyruvate is converted to either lactic acid or ethanol.
It is a process of anaerobic respiration where the pyruvic acid undergoes reduction by addition of one proton and two electrons donated by NADH+H+ to form lactic acid as the product and NAD+ as the byproduct of oxidation. Skeletal muscles usually derive energy by this process.
Alcoholic fermentation is a type of anaerobic respiration where the pyruvate is decarboxylated to acetaldehyde. The acetaldehyde is then reduced by NADH+H+ to ethanol and Carbon dioxide. Since ethanol is produced during the process, it is termed alcoholic fermentation.

Question 8.
Name the products of lactic acid fermentation.
It is a process of anaerobic respiration where the pyruvic acid undergoes reduction by addition of one proton and two electrons donated by NADH+H+ to form lactic acid as the product and NAD+ as the byproduct of oxidation. Skeletal muscles usually derive energy by this process.

Question 9.
Write the chemical reaction of lactic acid fermentation.
It is a process of anaerobic respiration where the pyruvic acid undergoes reduction by addition of one proton and two electrons donated by NADH+H+ to form lactic acid as the product and NAD+ as the byproduct of oxidation. Skeletal muscles usually derive energy by this process.

Question 10.
Explain alcoholic fermentation.
Alcoholic fermentation is a type of anaerobic respiration where the pyruvate is decarboxylated to acetaldehyde. The acetaldehyde is then reduced by NADH+H+ to ethanol and Carbon dioxide. Since ethanol is produced during the process, it is termed alcoholic fermentation.

Question 11.
Less energy is produced during anaerobic respiration that in aerobic respiration. Justify.
Anaerobic respiration produces less energy because:

1. Incomplete breakdown of respiratory substrate takes place.
2. Some of the products of anaerobic respiration can be oxidised further to release energy which shows that anaerobic respiration does not liberate the whole energy contained in the respiratory substrate.
3. NADH2 does not produce ATP, as electron transport is absent.
4. Only 2 ATP molecules are generated from one molecule of glucose during anaerobic respiration.

Question 12.
Enlist steps involved in aerobic respiration.
It involves glycolysis, acetyl CoA formation (connecting link reaction), Krebs cycle, electron transfer chain reaction and terminal oxidation.

Question 13.
Write the reaction of connecting link between glycolysis and Krebs cycle.
This reaction is called as ‘connecting link’ reaction between glycolysis and Krebs cycle.

Question 14.
How glycolysis is regulated?
Glycolysis is strongly regulated by the complex interplay between ATP consumption, NADH2 regeneration and regulation of various glycolytic enzymes like hexokinase, PFK-1, pyruvate kinase, etc. Besides, it is also controlled by hormones like glucagon, epinephrine and insulin.

Question 15.
Write the significance of ETS.
Significance of ETS:

1. Major amount of energy is generated through ETS or terminal oxidation in the form of ATP molecules.
2. Per glucose molecule 38 ATP molecules are formed, out of which 34 ATP molecules are produced through ETS.
4. In this process, energy is released in a controlled and stepwise manner to prevent any damage to the cell.
5. ETS produces water molecules.

Question 16.
Give the schematic representation of glycolysis.
Glycolysis is a process where glucose is broken down into two molecules of pyruvic acid, hence called glycolysis (glucose-breaking). It is common to both aerobic and anaerobic respiration. It occurs in the cytoplasm of the cell. It involves ten steps.
Glycolysis consists of two major phases:
1. Preparatory phase (1-5 steps).
2. Payoff phase (6-10 steps).
1. Preparatory phase:
a. In this phase, glucose is phosphorylated twice by using two ATP molecules and a molecule of fructose 1,6-bisphosphate is formed.
b. It is then cleaved into two molecules of glyceraldehyde-3-phosphate and dihydroxy acetone phosphate. These two molecules are 3-carbon carbohydrates (trioses) and are isomers of each other.
c. Dihydroxy acetone phosphate is isomerised to second molecule of glyceraldehyde-3-phosphate.
d. Therefore, two molecules of glyceraldehyde-3- phosphate are formed.
e. Preparatory phase of glycolysis ends.

2. Payoff phase:
a. In this phase, both molecules of glyceraldehyde-3-phosphate are converted to two molecules of 1,3- bisphoglycerate by oxidation and phosphorylation. Here, the phosphorylation is brought about by inorganic phosphate instead of ATP.
b. Both molecules of 1, 3-bisphosphoglycerate are converted into two molecules of pyruvic acid through series of reactions accompanied with release of energy. This released energy is used to produce ATP (4 molecules) by substrate-level phosphorylation.

Question 17.
Describe the formation of Acetyl Co-A in respiration.

1. The conversion of pyruvic acid to acetyl CoA is an oxidative decarboxylation reaction.
2. It is catalyzed by a multienzyme complex-pyruvate dehydrogenase complex (PDH). This enzyme is present in mitochondria of eukaryotes and cytosol of prokaryotes.
3. This reaction is called as ‘connecting link’ reaction between glycolysis and Krebs cycle.

Question 18.
Give the schematic representation of the overall view of Krebs cycle.

1. Krebs cycle or citric acid cycle is the second phase of aerobic respiration which takes place in the matrix of the mitochondria.
2. The acetyl CoA formed during the link reaction undergoes aerobic oxidation.
3. This cycle serves a common oxidative pathway for carbohydrates, fats and proteins.
4. In mitochondria pyruvic acid is decarboxylated and the remaining 2-carbon fragment is combined with a molecule of coenzyme A to form acetyl-CoA.
5. This reaction is an oxidative decarboxylation process and produces H+ ions and electrons along with carbon dioxide. During the process NAD+ is reduced to NADH+H+.
6. P-oxidation of fatty acids also produces acetyl-CoA as the end product.
7. Acetyl-CoA from both sources is condensed with oxaloacetic acid to form citric acid. Citric acid is oxidized step-wise by mitochondrial enzymes, releasing carbon dioxide.
8. Regeneration of oxaloacetic acid occurs to complete the cycle.
9. There are four steps of oxidation in this cycle, catalyzed by dehydrogenases (oxidoreductases) using NAD+ or FAD+ as the coenzyme.
10. The coenzymes are consequently reduced to NADH+H+ and FADH2 respectively. These transfer their electrons to the mitochondrial respiratory chain to get reoxidised.
11. One molecule of GTP (ATP) is also generated for every molecule of citric acid oxidized.

Question 19.
Explain why the respiratory pathway is an amphibolic pathway?

1. Respiration is considered as a catabolic process; however, it is not entirely correct in case of Krebs cycle.
2. Many reactions of Krebs cycle involve oxidation of acetyl CoA to release energy and C02.
3. However, the breakdown of respiratory substrates provides intermediates like a-ketoglutarate, oxaloacetate are used as precursors for synthesis of fatty acids, glutamic acid and aspartic acid respectively.
4. Thus, as the same respiratory process acts as catabolic as well as anabolic pathway for synthesis of various intermediate metabolic products, it is called amphibolic pathway.

Question 20.
Write a detailed note on the connecting link between glycolysis and Krebs cycle.

1. The conversion of pyruvic acid to acetyl CoA is an oxidative decarboxylation reaction.
2. It is catalyzed by a multienzyme complex-pyruvate dehydrogenase complex (PDH). This enzyme is present in mitochondria of eukaryotes and cytosol of prokaryotes.
3. This reaction is called as ‘connecting link’ reaction between glycolysis and Krebs cycle.

Question 21.
Give the diagrammatic representation of ETS.

1. NADH2 and FADH2 produced during glycolysis, connecting link reaction and Krebs cycle are oxidized with the help of various electron carriers and enzymes.
2. These carriers and enzymes are arranged on inner mitochondrial membrane in the form of various complexes as complex I, II, III, VI and V.
3. NADH+H+ is oxidised by NADH dehydrogenase (complex I) and it’s electrons are transferred to ubiquinone (coenzyme Q-CoQ) present on inner membrane of mitochondria. Reduced ubiquinone is called as ubiqunol.
4. FADH2 is oxidised by complex II (Succinate dehydrogenase) and these electrons are also transferred to CoQ.
5. During oxidation of NADH+H+ and FADH2, electrons and protons are released but only electrons are canned forward whereas protons are released into outer chamber of mitochondria (intermembrane space).
6. Ubiquinol is oxidised by complex-III (Cytochrome bcl complex) and it’s electrons are transferred to cytochrome C.
7. Cytochrome C is a small, iron-containing protein, loosely associated with inner membrane. It acts as a mobile electron carrier, transferring the electrons between complex III and IV.
8. Cytochrome C is oxidised by complex IV or cytochrome C oxidase consisting of cytochrome a and a3. Electrons are transferred by this complex to the molecular oxygen. This is terminal oxidation.
9. Reduced molecular oxygen reacts with protons to form water molecule called as metabolic water.
10. Protons necessary for this are channelled from outer chamber of mitochondria into inner chamber by F0 part of oxysome (complex V) present in inner mitochondrial membrane.
11. This proton channelling by F0 is coupled to catalytic site of F1 which catalyses the synthesis of ATP from ADP and inorganic phosphate. This is oxidative phosphorylation.
12. As transfer of protons is accompanied with synthesis of ATP, this process is named as ‘Chemiosmosis’ by Peter Mitchell.

Question 22.
Explain the process of terminal oxidation. Give its significance (any two points).

1. NADH2 and FADH2 produced during glycolysis, connecting link reaction and Krebs cycle are oxidized with the help of various electron carriers and enzymes.
2. These carriers and enzymes are arranged on inner mitochondrial membrane in the form of various complexes as complex I, II, III, VI and V.
3. NADH+H+ is oxidised by NADH dehydrogenase (complex I) and it’s electrons are transferred to ubiquinone (coenzyme Q-CoQ) present on inner membrane of mitochondria. Reduced ubiquinone is called as ubiqunol.
4. FADH2 is oxidised by complex II (Succinate dehydrogenase) and these electrons are also transferred to CoQ.
5. During oxidation of NADH+H+ and FADH2, electrons and protons are released but only electrons are canned forward whereas protons are released into outer chamber of mitochondria (intermembrane space).
6. Ubiquinol is oxidised by complex-III (Cytochrome bcl complex) and it’s electrons are transferred to cytochrome C.
7. Cytochrome C is a small, iron-containing protein, loosely associated with inner membrane. It acts as a mobile electron carrier, transferring the electrons between complex III and IV.
8. Cytochrome C is oxidised by complex IV or cytochrome C oxidase consisting of cytochrome a and a3. Electrons are transferred by this complex to the molecular oxygen. This is terminal oxidation.
9. Reduced molecular oxygen reacts with protons to form water molecule called as metabolic water.
10. Protons necessary for this are channelled from outer chamber of mitochondria into inner chamber by F0 part of oxysome (complex V) present in inner mitochondrial membrane.
11. This proton channelling by F0 is coupled to catalytic site of F1 which catalyses the synthesis of ATP from ADP and inorganic phosphate. This is oxidative phosphorylation.
12. As transfer of protons is accompanied with synthesis of ATP, this process is named as ‘Chemiosmosis’ by Peter Mitchell.

Question 23.
1. Enlist the main steps involved in aerobic respiration and their place of occurrence.
2. Differentiate between photosynthesis and aerobic respiration.
1. Glycolysis takes place in the cytoplasm of a cell.
2. It is catalyzed by a multienzyme complex-pyruvate dehydrogenase complex (PDH). This enzyme is present in mitochondria of eukaryotes and cytosol of prokaryotes.,
3. Krebs cycle or citric acid cycle is the second phase of aerobic respiration which takes place in the matrix of the mitochondria. and These carriers and enzymes are arranged on inner mitochondrial membrane in the form of various complexes as complex I, II, III, VI and V.

Question 24.
1. Give the schematic representation of ETS.
2. Differentiate between respiration and combustion.

1. NADH2 and FADH2 produced during glycolysis, connecting link reaction and Krebs cycle are oxidized with the help of various electron carriers and enzymes.
2. These carriers and enzymes are arranged on inner mitochondrial membrane in the form of various complexes as complex I, II, III, VI and V.
3. NADH+H+ is oxidised by NADH dehydrogenase (complex I) and it’s electrons are transferred to ubiquinone (coenzyme Q-CoQ) present on inner membrane of mitochondria. Reduced ubiquinone is called as ubiqunol.
4. FADH2 is oxidised by complex II (Succinate dehydrogenase) and these electrons are also transferred to CoQ.
5. During oxidation of NADH+H+ and FADH2, electrons and protons are released but only electrons are canned forward whereas protons are released into outer chamber of mitochondria (intermembrane space).
6. Ubiquinol is oxidised by complex-III (Cytochrome bcl complex) and it’s electrons are transferred to cytochrome C.
7. Cytochrome C is a small, iron-containing protein, loosely associated with inner membrane. It acts as a mobile electron carrier, transferring the electrons between complex III and IV.
8. Cytochrome C is oxidised by complex IV or cytochrome C oxidase consisting of cytochrome a and a3. Electrons are transferred by this complex to the molecular oxygen. This is terminal oxidation.
9. Reduced molecular oxygen reacts with protons to form water molecule called as metabolic water.
10. Protons necessary for this are channelled from outer chamber of mitochondria into inner chamber by F0 part of oxysome (complex V) present in inner mitochondrial membrane.
11. This proton channelling by F0 is coupled to catalytic site of F1 which catalyses the synthesis of ATP from ADP and inorganic phosphate. This is oxidative phosphorylation.
12. As transfer of protons is accompanied with synthesis of ATP, this process is named as ‘Chemiosmosis’ by Peter Mitchell.

Question 25.
Enlist the different respiratory substrate.
Respiratory substrates are the molecules that are oxidized during respiration to release energy which can be used for ATP synthesis. Carbohydrates, fats and proteins are the common respiratory substrate. Glucose is the most common respiratory substrate.

Question 26.
Define R.Q. What is its value for fats?
1. Respiratory quotient (R.Q.) or respiratory ratio is the ratio of volume of CO2 released to the volume of O2 consumed in respiration.
2. R.Q. = Volume of CO2 released/Volume of O2 consumed

Question 27.
Write the significance of respiration.

1. Respiration provides energy for biosynthesis of biomolecules.
2. It is also a source of energy for cell division, growth, repairs and replacement of worn out parts, movements,
locomotion etc.
3. Various intermediates of Krebs cycle are used as building blocks for synthesis of other complex compounds.
4. Coupled with photosynthesis, it helps to maintain the balance between C02 and O2 in the atmosphere.
5. Anaerobic respiration (fermentation) is used in various industries such as dairies, bakeries, distilleries, leather industries, paper industries etc. It is used in the commercial production of alcohol, organic acids, vitamins, antibiotics etc.

Question 47.
Multiple Choice Questions:

Question 1.
Respiration is regarded as a ________ process.
(A) catabolic
(B) anabolic
(C) reduction
(D) synthetic
(A) catabolic

Question 2.
Anaerobic respiration is also called as ________ .
(A) Glycolysis
(B) fermentation
(C) phosphoryaltion
(D) decarboxylation
(B) fermentation

Question 3.
The first compound formed in glycolysis is
(A) Glucose-6-phosphate
(B) Glucose-1,6-biphosphate
(C) Fructose-6-phosphate
(D) Pyruvic acid
(A) Glucose-6-phosphate

Question 4.
Which of the following compounds in last step of glycolysis gives pyruvic acid?
(A) 3 – phosphoglyceraldehyde
(B) dihydroxy acetone phosphate
(C) phosphoenolpyruvate
(D) 2-phosphoglycerate
(C) phosphoenolpyruvate

Question 5.
In glycolysis, dehydration occurs during formation of
(A) 3 – phosphoglyceraldehyde
(B) 2 – phosphoglycerate
(C) phosphoenolpyruvate
(D) dihydroxyacetone phosphate
(B) 2 – phosphoglycerate

Question 6.
In which of the following steps dehydrogenation occurs?
(A) Glucose → Glucose 6-phosphate
(B) 3-phophoglcerate → 2-phophoglccratc
(C) phosphoenolpyruvate → pyruvate
(D) 3 – phosphoglyceraldehyde → 1, 3-bisphosphoglycerate
(D) 3 – phosphoglyceraldehyde → 1, 3-bisphosphoglycerate

Question 7.
The compound common to both aerobic and anaerobic respiration is
(A) C02
(B) pyruvic acid
(C) acetyl CoA
(D) free oxygen
(B) pyruvic acid

Question 8.
Which compound is found both in respiration and photosynthesis?
(A) Phosphoglycerate
(B) Phosphoglyceraldehyde
(C) Both (A) and (B)
(D) Succinic acid
(C) Both (A) and (B)

Question 9.
Which type of respiration does not release C02?
(A) Aerobic respiration
(B) Alcoholic fermentation
(C) Lactic acid fermentation
(D) Krebs cycle
(C) Lactic acid fermentation

Question 10.
What is the overall goal of glycolysis, Krebs cycle and electron transport system?
(A) Synthesis of ATP in fermentation reaction
(B) Carbohydrates
(C) Nucleic acids
(D) ATP in small stepwise units
(D) ATP in small stepwise units

Question 11.
The intermediate between glycolysis and TCA cycle is:
(A) Lactic acid
(B) Acetaldehyde
(C) Fructose-6-phosphate
(D) Acetyl Co-A
(D) Acetyl Co-A

Question 12.
During alcoholic fermentation, decarboxylation of pyruvate gives
(A) acetaldehyde
(B) lactic acid
(C) ethyl alcohol
(D) methyl alcohol
(A) acetaldehyde

Question 13.
Where the link reaction occurs in prokaryotes?
(A) cytoplasm
(B) mitochondrial matrix
(C) cell membrane
(D) mitochondrial membrane
(A) cytoplasm

Question 14.
In Krebs cycle, dehydration of substrate occurs
(A) once
(B) twice
(C) thrice
(D) four times
(A) once

Question 15.
Which of the following steps generate ATP without ETS?
(A) Pyruvic acid → Acetyl Co-A
(B) ∝-ketoglutarate → Succinic acid
(C) Iso-citric acid → Oxalosuccinic acid
(D) Succinyl Co-A → Succinic acid
(D) Succinyl Co-A → Succinic acid

Question 16.
In Krebs cycle, the acid which undergoes oxidative decarboxylation is
(A) citric acid
(B) succinic acid
(C) malic acid
(D) ∝-ketoglutaric acid
(D) ∝-ketoglutaric acid

Question 17.
During Krebs cycle, fumaric acid gets converted into malic acid by
(A) decarboxylation
(B) dehydrogenation
(C) dehydration
(D) hydration
(D) hydration

Question 18.
Krebs cycle is also called TCA cycle because
(A) the first compound formed is citric acid.
(B) it was discovered by Sir Hans Krebs.
(C) organic acids formed have 3 carboxylic acid groups.
(D) acetyl Co-A is formed
(C) organic acids formed have 3 carboxylic acid groups.

Question 19.
Which of the following compound is the acceptor of Acetyl Co-A in Krebs cycle?
(A) Oxaloacetic acid
(B) Fumaric acid
(C) Malic acid
(D) Oxalo succinic acid
(A) Oxaloacetic acid

Question 20.
Which of the following compounds is formed in Krebs cycle from fumaric acid?
(A) Oxalo acetic acid
(B) Malic acid
(C) ∝-KGA
(D) Citric acid
(B) Malic acid

Question 21.
Which of the following step of aerobic respiration would be omitted when fatty acids are used as respiratory substrate?
(A) Glycolysis
(B) Krebs cycle
(C) Electron transfer chain reaction
(D) Terminal oxidation.
(A) Glycolysis

Question 22.
During Krebs cycle, decarboxylation occurs _______ time/s.
(A) 1
(B) 2
(C) 3
(D) 4
(B) 2

Question 23.
The conversion of malic acid to oxalo acetic acid is catalyzed by
(A) malate reductase
(B) malate thiokinase
(C) fumarase
(D) malate dehydrogenase
(D) malate dehydrogenase

Question 24.
Electron carriers of oxidative phosphorylation are present on
(A) outer membrane of mitochondria.
(B) inner membrane of mitochondria.
(C) thylakoid membrane of chloroplast.
(D) matrix of mitochondria.
(B) inner membrane of mitochondria.

Question 25.
Which of the following derives maximum energy per molecule of glucose?
(A) Alcoholic fermentation.
(B) Lactic acid fermentation.
(C) Aerobic respiration in unicellular organisms.
(D) Glycolysis in liver cells.
(C) Aerobic respiration in unicellular organisms.

Question 26.
The cytochrome which donates de-energised electron to oxygen is
(A) cytochrome-a
(B) cytochrome-b
(C) cytochrome-a3
(D) cytochrome-c
(C) cytochrome-a3

Question 27.
In terminal oxidation FADH2 is oxidized by
(A) complex I
(B) complex II
(C) complex III
(D) complex IV
(B) complex II

Question 28.
The net gain of energy from a molecule of glucose in the aerobic respiration is
(A) 38
(B) 35
(C) 70
(D) 76
(A) 38

Question 29.
Each molecule of NADH2 through ETS yields
(A) 1 ATP
(B) 2 ATPs
(C) 3 ATPs
(D) 4 ATPs
(C) 3 ATPs

Question 30.
One glucose molecule, through ETS yields
(A) 2 ATP molecules
(B) 3 ATP molecules
(C) 34 ATP molecules
(D) 38 ATP molecules
(C) 34 ATP molecules

Question 31.
The adenosine triphosphate (ATP) gain during glycolysis, connecting link and Krebs cycle respectively are _______ .
(A) 8, 6,24
(B) 8,24, 6
(C) 24, 8, 6
(D) 6, 8, 24
(A) 8, 6,24

Question 32.
The respiratory quotient (R.Q.) of carbohydrate is ________ .
(A) 0.7
(B) 1
(C) 0.9
(D) 0.1
(B) 1

Question 33.
R. Q. for proteins is about _______ .
(A) 0.7
(B) 0.8
(C) 0.9
(D) 1.0
(C) 0.9

Question 48.
Competitive Corner:

Question 1.
Which of the following statements regarding mitochondria is INCORRECT?
(A) Inner membrane is convoluted with infoldings.
(B) Mitochondrial matrix contains single circular DNA molecule and ribosomes.
(C) Outer membrane is permeable to monomers of carbohydrates, fats and proteins.
(D) Enzymes of electron transport are embedded in outer membrane.
Hint: Enzymes of electron transport are embedded in inner membrane.
(D) Enzymes of electron transport are embedded in outer membrane.

Question 2.
Where is the respiratory electron transport system (ETS) located in plants?
(A) Intermembrane space
(B) Mitochondrial matrix
(C) Outer mitochondrial membrane
(D) Inner mitochondrial membrane
(D) Inner mitochondrial membrane

Question 3.
In case of anaerobic respiration, the R.Q is _____ .
(A) always less than one
(B) always more than one
(C) always infinity
(D) Variable on the basis of substrate.
(C) always infinity

Question 4.
The net gain of ATP molecules during aerobic breakdown of one glucose molecule is _______ .
(A) 40
(B) 38
(C) 36
(D) 30
(B) 38

Question 5.
During glycolysis the compounds PGAL and DHAP are formed from fructose 1,6- diphosphate by _______ .
(A) cleavage
(B) isomerisation
(C) phosphorylation
(D) condensation
(A) cleavage

Question 6.
Number of oxygen molecules utilized in glycolysis is ________ .
(A) 0
(B) 2
(C) 4
(D) 6
(A) 0

## Maharashtra Board Class 11 Information Technology Important Questions Chapter 4 Cyber Law

Balbharati Maharashtra State Board Class 11 Information Technology Important Questions Chapter 4 Cyber Law Important Questions and Answers.

## Maharashtra State Board 11th Information Technology Important Questions Chapter 4 Cyber Law

1. Fill in the Blanks.

Question 1.
__________ is the area of law that deals with the Internet’s relationship to technological and electronic elements.
Cyberlaw

Question 2.
__________ is the part of the overall legal system that deals with the Internet, cyberspace, and their respective legal issues.
Cyberlaw

Question 3.
__________ covers a fairly broad area, encompassing several subtopics including freedom of expression, access to and usage of the Internet, and online privacy.
Cyberlaw

Question 4.
The attempts to change outdated laws and provides ways to deal with cybercrimes.
Information Technology Act 2000

Question 5.
The Act offers the much-needed legal framework so that information is not denied.
Information Technology

Question 6.
The Act has also proposed a legal framework for the authentication and origin of an electronic records.
Information Technology

Question 7.
__________ is also called moral philosophy is the discipline concerned with what is morally good and bad, right or wrong.
Ethics

Question 8.
__________ is the standards of behaviour; principles of right and wrong behaviour.
Morals

Question 9.
Thus __________ are dictated by society, culture or religion.
Morals

Question 10.
Computer Crime is alternatively referred to as __________
Cybercrime

Question 11.
Computer crime is an act performed by a knowledgeable computer user, sometimes referred to as a __________
Hacker

Question 12.
A __________ who illegally browses or steals a company’s or individual’s private information.
Hacker

Question 13.
__________ can involve criminal activities that are traditional in nature, such as theft, fraud, forgery, defamation and mischief.
Cybercrimes

Question 14.
__________ is nothing but copyright violation of software created originally by an individual or an institution.
Software piracy

Question 15.
__________ includes stealing of codes/programs and other information illegally and creating the imitated copy by unauthorized means.
Software piracy

Question 16.
Gaining access without the users’ permission is known as __________
Unauthorized Access

Question 17.
__________ means granting access rights to resources.
Authorization

Question 18.
A __________ is a legal right that gives the creator of a literary, artistic, musical, or other creative work.

Question 19.
__________ owners have the right to control the reproduction of their work, including the right to receive the royalty payment for that reproduction.

Question 20.
Activity such as decipher codes or passwords and breaking security systems for illegal reasons is called __________
Cracking

Question 21.
The cracker will use a program or script known as a __________
Crack

Question 22.
__________ is a criminal practice where an individual uses the Internet to systematically harass or threaten someone.
Cyberstalking

Question 23.
__________ is a technique of extracting confidential information such as credit card numbers and username password combos by pretending as a legal enterprise.
Phishing

Question 24.
__________ is typically carried out by email spoofing.
Phishing

Question 25.
__________ is presenting someone else’s work or idea as your own without their consent.
Plagarism

Question 26.
__________ refers to unauthorised intrusion into a computer or a network.
Hacking

Question 27.
__________ is a person intensely interested in the deep and hidden or concealed working of any computer operating system and programming language.
Hacker

Question 28.
__________ is a method of converting the original message into random text.
Encryption

Question 29.
Full form of SSL is __________
Secure Socket Layer

Question 30.
Through the __________, transmission of data is encrypted.
Secure Socket Layer

Question 31.
__________ refers to a network security (Hardware and Software) system which blocks certain types of information.
Firewall

Question 32.
__________ is an Act to provide legal recognition for transactions carried out by means of electronic data interchange and other means of electronic communication.
Information Technology Act, 2000

Question 33.
__________ aims to provide the legal infrastructure for E-Commerce in India.
Information Technology Act, 2000

Question 34.
The __________ have a major impact on E-Businesses and the new economy in India.
Cyber laws

Question 35.
The __________ also aims to provide for the legal framework.
Information Technology Act, 2000

Question 36.
__________ has been replaced with the electronic signature to make it a more technology-neutral act.
Digital Signature

2. True or False.

Question 1.
Criminal Law is the area of law that deals with the Internet’s relationship to technological and electronic elements.
False

Question 2.
Cyberlaw is the part of the overall legal system that deals with the Internet, cyberspace, and their respective legal issues.
True

Question 3.
Cyberlaw covers a fairly broad area, encompassing several subtopics including freedom of expression, access to and usage of the Internet, and online privacy.
True

Question 4.
The Information Technology Act 2000 attempts to change outdated laws and provides ways to deal with cybercrimes.
True

Question 5.
The Information Technology Act offers the much-needed legal framework so that information is not denied.
True

Question 6.
The Computer Act has also proposed a legal framework for the authentication and origin of an electronic records.
False

Question 7.
Morals are also called moral philosophy is the discipline concerned with what is morally good and bad, right or wrong.
False

Question 8.
Ethics is the standards of behaviour; principles of right and wrong behaviour.
False

Question 9.
Thus Morals are dictated by society, culture, or religion.
True

Question 10.
Computer Crime is alternatively referred to as Hacker.
False

Question 11.
Computer crime is an act performed by a knowledgeable computer user, sometimes referred to as a Hacker.
True

Question 12.
A Cybercrime who illegally browses or steals a company’s or individual’s private information.
False

Question 13.
Cybercrimes can involve criminal activities that are traditional in nature, such as theft, fraud, forgery, defamation, and mischief.
True

Question 14.
Software piracy is nothing but copyright violation of software created originally by an individual or an institution.
True

Question 15.
Unauthorized access includes stealing of codes/programs and other information illegally and creating the imitated copy by unauthorized means.
False

Question 16.
Gaining access without the user’s permission is known as Software piracy.
False

Question 17.
Authorization means granting access rights to resources.
True

Question 18.
Cracking is a legal right that gives the creator of a literary, artistic, musical, or other creative work.
False

Question 19.
Copyright owners have the right to control the reproduction of their work, including the right to receive the royalty payment for that reproduction.
True

Question 20.
Activity such as decipher codes or passwords and breaking security systems for illegal reasons is called copyright.
False

Question 21.
The cracker will use a program or script known as a Crack.
True

Question 22.
Cyberstalking is a criminal practice where an individual uses the Internet to systematically harass or threaten someone.
True

Question 23.
Phishing is a technique of extracting confidential information such as credit card numbers and username password combos by pretending as a legal enterprise.
True

Question 24.
Phishing is typically carried out by email spoofing.
True

Question 25.
Plagiarism is presenting someone else’s work or idea as your own without their consent.
True

Question 26.
Hacking refers to unauthorized intrusion into a computer or a network.
True

Question 27.
Hacker is a person intensely interested in the deep and hidden or concealed working of any computer operating system and programming language.
True

Question 28.
Encryption is a method of converting the original message into random text.
True

Question 29.
The full form of SSL is Secure Socket Layer.
True

Question 30.
Through the Encryption transmission of data is encrypted.
False

Question 31.
Encryption refers to a network security (Hardware and Software) system which blocks certain types of information.
False

Question 32.
A digital signature is an Act to provide legal recognition for transactions carried out by means of electronic data interchange and other means of electronic communication.
False

Question 33.
Information Technology Act, 2000 aims to provide the legal infrastructure for E-Commerce in India.
True

Question 34.
Cyber laws have a major impact on E-Businesses and the new economy in India.
True

Question 35.
The Information Technology Act, 2000 also aims to provide for the legal framework.
True

Question 36.
Cyber laws have been replaced with electronic signatures to make it a more technology-neutral act.
False

3. Multiple Choice Question (Single Choice)

Question 1.
__________ is the area of law that deals with the Internet’s relationship to technological and electronic elements.
(A) Cyberlaw
(B) Criminal Law
(D) Internet Law
(A) Cyberlaw

Question 2.
__________ is the part of the overall legal system that deals with the Internet, cyberspace, and their respective legal issues.
(A) Cyberlaw
(B) Criminal Law
(D) Internet Law
(A) Cyberlaw

Question 3.
__________ covers a fairly broad area, encompassing several subtopics including freedom of expression, access to and usage of the Internet, and online privacy.
(A) Cyberlaw
(B) Criminal Law
(D) Internet Law
(A) Cyberlaw

Question 4.
The __________ attempts to change outdated laws and provides ways to deal with cybercrimes.
(A) Information Technology Act 2000
(B) Cyber Rule
(C) Computer Act
(D) Legal Act
(A) Information Technology Act 2000

Question 5.
The __________ Act offers the much-needed legal framework so that information is not denied.
(A) Cyber Rule
(B) Information Technology
(C) Computer Act
(D) Legal Act
(B) Information Technology

Question 6.
The __________ Act has also proposed a legal framework for the authentication and origin of an electronic records.
(A) Cyber Rule
(B) Information Technology
(C) Computer Act
(D) Legal Act
(B) Information Technology

Question 7.
__________ is also called moral philosophy is the discipline concerned with what is morally good and bad, right or wrong.
(A) Ethics
(B) Morals
(C) Society
(D) Culture
(A) Ethics

Question 8.
__________ is the standards of behaviour; principles of right and wrong behaviour.
(A) Ethics
(B) Morals
(C) Society
(D) Culture
(B) Morals

Question 9.
Thus __________ are dictated by society, culture or religion.
(A) Ethics
(B) Morals
(C) Society
(D) Culture
(B) Morals

Question 10.
Computer Crime is alternatively referred to as __________
(A) Cybercrime
(B) Hacker
(C) Computer crime
(D) Illegal Act
(A) Cybercrime

Question 11.
Computer crime is an act performed by a knowledgeable computer user, sometimes referred to as a __________
(A) Cybercrime
(B) Hacker
(C) Computer crime
(D) Illegal Act
(B) Hacker

Question 12.
A __________ who illegally browses or steals a company’s or individual’s private information.
(A) Cybercrime
(B) Hacker
(C) Computer crime
(D) Illegal Act
(B) Hacker

Question 13.
__________ can involve criminal activities that are traditional in nature, such as theft, fraud, forgery, defamation, and mischief.
(A) Cybercrimes
(B) Hacker
(C) Computer crime
(D) Illegal Act
(A) Cybercrimes

Question 14.
__________ is nothing but copyright violation of software created originally by an individual or an institution.
(A) Software piracy
(B) Unauthorized access
(C) Authorization
(A) Software piracy

Question 15.
__________ includes stealing of codes/programs and other information illegally and creating the imitated copy by unauthorized means.
(A) Software piracy
(B) Unauthorized access
(C) Authorization
(A) Software piracy

Question 16.
Gaining access without the users’ permission is known as __________
(A) Software piracy
(B) Unauthorized access
(C) Authorization
(B) Unauthorized access

Question 17.
__________ means granting access rights to resources.
(A) Software piracy
(B) Unauthorized access
(C) Authorization
(C) Authorization

Question 18.
A __________ is a legal right that gives the creator of a literary, artistic, musical, or other creative work.
(A) Software piracy
(B) Unauthorized access
(C) Authorization

Question 19.
__________ owners have the right to control the reproduction of their work, including the right to receive the royalty payment for that reproduction.
(A) Software piracy
(B) Unauthorized access
(C) Authorization

Question 20.
Activity such as decipher codes or passwords and breaking security systems for illegal reasons is called __________
(A) Cracking
(B) Crack
(C) Cyberstalking
(D) Phishing
(A) Cracking

Question 21.
The cracker will use a program or script known as a __________
(A) Cracking
(B) Crack
(C) Cyberstalking
(D) Phishing
(B) Crack

Question 22.
__________ is a criminal practice where an individual uses the Internet to systematically harass or threaten someone.
(A) Cracking
(B) Crack
(C) Cyberstalking
(D) Phishing
(C) Cyberstalking

Question 23.
__________ is a technique of extracting confidential information such as credit card numbers and username password combos by pretending as a legal enterprise.
(A) Cracking
(B) Crack
(C) Cyberstalking
(D) Phishing
(D) Phishing

Question 24.
__________ is typically carried out by email spoofing.
(A) Cracking
(B) Crack
(C) Cyberstalking
(D) Phishing
(D) Phishing

Question 25.
__________ is presenting someone else’s work or idea as your own without their consent.
(A) Plagiarism
(B) Hacking
(C) Hacker
(D) A. Cracking
(A) Plagarism

Question 26.
__________ refers to unauthorised intrusion into a computer or a network.
(A) Plagiarism
(B) Hacking
(C) Hacker
(D) Cracking
(B) Hacking

Question 27.
__________ is a person intensely interested in the deep and hidden or concealed working of any computer operating system and programming language.
(A) Plagiarism
(B) Hacking
(C) Hacker
(D) Cracking
(C) Hacker

Question 28.
__________ is a method of converting the original message into random text.
(A) Encryption
(B) Secure Socket Layer
(C) Firewall
(D) Hardware
(A) Encryption

Question 29.
Full form of SSL is __________
(A) Secure Socket Layer
(B) Secure Switch Layer
(C) Secure Session Lesson
(D) System Secure Layer
(A) Secure Socket Layer

Question 30.
Through the __________, transmission of data is encrypted.
(A) Secure Socket Layer
(B) Secure Switch Layer
(C) Secure Session Lesson
(D) System Secure Layer
(A) Secure Socket Layer

Question 31.
__________ refers to a network security (Hardware and Software) system which blocks certain types of information.
(A) Encryption
(B) Secure Socket Layer
(C) Firewall
(D) Hardware
(C) Firewall

Question 32.
__________ is an Act to provide legal recognition for transactions carried out by means of electronic data interchange and other means of electronic communication.
(A) Information Technology Act, 2000
(B) Cyber laws
(C) Digital Signature
(D) Digital Certificate
(A) Information Technology Act, 2000

Question 33.
__________ aims to provide the legal infrastructure for e-commerce in India.
(A) Information Technology Act, 2000
(B) Cyber laws
(C) Digital signature
(D) Digital Certificate
(A) Information Technology Act, 2000

Question 34.
The __________ have a major impact on E-Businesses and the new economy in India.
(A) Information Technology Act, 2000
(B) Cyber Laws
(C) Digital signature
(D) Digital Certificate
(B) Cyber Laws

Question 35.
The also aims to provide for the legal framework.
(A) Information Technology Act, 2000
(B) Cyber Laws
(C) Digital signature
(D) Digital Certificate
(A) Information Technology Act, 2000

Question 36.
__________ has been replaced with the electronic signature to make it a more technology-neutral act.
(A) Information Technology Act, 2000
(B) Cyber laws
(C) Digital Signature
(D) Digital Certificate
(C) Digital Signature

4. Multiple Choice Two Correct Answers.

Question 1.
The Information Technology Act 2000 attempts to change outdated __________ and provides ways to deal with __________
(A) Authentication
(B) Laws
(C) Electronic record
(D) Cybercrimes
(E) Morals
(B) Laws, (D) Cybercrimes

Question 2.
The Information Technology Act has also proposed a legal framework for the __________ and origin of __________
(A) Authentication
(B) Laws
(C) Electronic record
(D) Cybercrimes
(E) Morals
(A) Authentication, (C) Electronic record

Question 3.
Thus __________ are dictated by society, culture or religion while __________ are chosen by the person himself which governs his life.
(A) Authentication
(B) Laws
(C) Electronic record
(D) Morals
(E) Ethics
(D) Morals, (E) Ethics

Question 4.
Hacker is a person intensely interested in the deep and hidden or concealed working of any computer __________ and __________
(A) Operating System
(B) Programming Language
(C) Individual
(D) Institution
(A) Operating System, (B) Programming Language

Question 5.
Software piracy is nothing but copyright violation of software created originally by an __________ or an __________
(A) Operating system
(B) Programming language
(C) Individual
(D) Institution
(C) Individual, (D) Institution

Question 6.
Activity such as __________ or __________ and breaking security systems for illegal reasons is called cracking.
(A) Operating system
(B) Programming language
(C) Individual
(D) Decipher Codes

Question 7.
Phishing is a technique of extracting confidential information such as __________ and __________ combos by pretending as a legal enterprise.
(A) Computer
(B) Credit Card Numbers
(C) Network
(E) Programming Language

Question 8.
Hacking refers to unauthorised intrusion into a __________ or a __________
(A) Computer
(B) Credit Card Numbers
(C) Network
(E) Programming Language
(A) Computer, (C) Network

Question 9.
Hacker is a person intensely interested in the deep and hidden or concealed working of any computer __________ and __________
(A) Operating system
(B) Programming language
(C) Individual
(D) Decipher Codes
(A) Operating system, (B) Programming language

Question 10.
Encryption is a method of converting the __________ message into __________ text.
(A) Original
(B) Random
(C) Hardware
(D) Software
(E) Electronic communication
(A) Original, (B) Random

Question 11.
Firewall refers to network security __________ and __________ system which blocks certain type of information.
(A) Original
(B) Random
(C) Hardware
(D) Software
(E) Electronic communication
(C) Hardware, (D) Software

Question 12.
Information Technology Act, 2000 is an Act to provide legal recognition for transaction carried out by means of __________ and other means of __________
(A) Original
(B) Random
(C) Hardware
(D) Electronic Data Interchange
(E) Electronic Communication
(D) Electronic Data Interchange, (E) Electronic Communication

Question 13.
Information Technology Act, 2000 aims to provide the __________ infrastructure for __________ in India.
(A) Legal
(B) E-Commerce
(C) Original
(D) Random
(E) Hardware
(A) Legal, (B) E-Commerce

5. Multiple Choice Three Correct Answers.

Question 1.
Cyberlaw is the area of law that deals with the Internet’s relationship to technological and electronic elements, including computers, __________, __________ and __________
(A) Software
(B) Internet
(C) Hardware
(D) Legal Issues
(E) Information Systems
(A) Software, (C) Hardware, (E) Information Systems

Question 2.
Cyberlaw is the part of the overall legal system that deals with the __________, __________, and their respective __________
(A) Software
(B) Internet
(C) Cyberspace
(D) Legal Issues
(E) Information Systems
(B) Internet, (C) Cyberspace, (D) Legal Issues

Question 3.
(A) Freedom of expression
(B) Usage of the Internet
(C) Online privacy
(D) Electronic Crime
(E) Hi-Tech Crime
(A) Freedom of expression, (B) Usage of the Internet, (C) Online privacy

Question 4.
Computer Crime is alternatively referred to as __________, __________ or __________
(A) Freedom of expression
(B) Usage of the Internet
(C) Cybercrime
(D) Electronic Crime
(E) Hi-Tech Crime
(C) Cybercrime, (D) Electronic Crime, (E) Hi-Tech Crime

Question 5.
Activity such as __________ codes or __________ and breaking __________ systems for illegal reasons is called cracking.
(A) Cyber Cafe
(B) Decipher
(C) Cyber Security
(E) Security
(B) Decipher, (D) Passwords, (E) Security

Question 6.
The IT Act 2000 was amended in 2008 and 2011 and it includes rules for __________, __________, __________ by service provider, Audit of electronic document etc.
(A) Cyber Cafe
(B) Decipher
(C) Cyber Security
(D) Delivery of Services
(E) Security
(A) Cyber Cafe, (C) Cyber Security, (D) Delivery of Services

6. Match the following.

Question 1.

 Column ‘A’ Column ‘B’ (1) Ethics (A) Computer Crime (2) Morals (B) Principles of right and wrong (3) Cyber Crime (C) Moral philosophy (4) Hacker (D) Illegally browses or steals a company’s or individual’s private information

 Column ‘A’ Column ‘B’ (1) Ethics (C) Moral philosophy (2) Morals (B) Principles of right and wrong (3) Cyber Crime (A) Computer Crime (4) Hacker (D) Illegally browses or steals a company’s or individual’s private information

Question 2.

 Column ‘A’ Column ‘B’ (1) Software Piracy (A) Legal right (2) Unauthorized access (B) Gaining access without the users’ permission (3) Authorization (C) Granting access rights to resources (4) Copyright (D) Copyright violation of software

 Column ‘A’ Column ‘B’ (1) Software Piracy (D) Copyright violation of software (2) Unauthorized access (B) Gaining access without the users’ permission (3) Authorization (C) Granting access rights to resources (4) Copyright (A) Legal right

Question 3.

 Column ‘A’ Column ‘B’ (1) Copyright owners (A) Have the right to control the reproduction of their work (2) Cracking (B) Will use a program or script known as a crack (3) Cracker (C) Breaking security systems for illegal reasons (4) Cyberstalking (D) Uses the Internet to systematically harass or threaten someone

 Column ‘A’ Column ‘B’ (1) Copyright owners (A) Have the right to control the reproduction of their work (2) Cracking (C) Breaking security systems for illegal reasons (3) Cracker (B) Will use a program or script known as a crack (4) Cyberstalking (D) Uses the Internet to systematically harass or threaten someone

Question 4.

 Column ‘A’ Column ‘B’ (1) Phishing (A) Technique of extracting confidential information (2) Plagiarism (B) Presenting someone else’s work or idea as your own without their consent (3) Hacking (C) Safe and responsible use of information and communication technology (4) Cyber Safety (D) Refers to unauthorized intrusion into a computer or a network

 Column ‘A’ Column ‘B’ (1) Phishing (A) Technique of extracting confidential information (2) Plagiarism (B) Presenting someone else’s work or idea as your own without their consent (3) Hacking (D) Refers to unauthorized intrusion into a computer or a network (4) Cyber Safety (C) Safe and responsible use of information and communication technology

Question 5.

 Column ‘A’ Column ‘B’ (1) Netiquette (A) Network Security (2) Encryption (B) Method of converting the original message into random text (3) Secure Socket Layer (C) Transmission of data is encrypted (4) Firewall (D) Internet etiquette

 Column ‘A’ Column ‘B’ (1) Netiquette (D) Internet etiquette (2) Encryption (B) Method of converting the original message into random text (3) Secure Socket Layer (C) Transmission of data is encrypted (4) Firewall (A) Network Security

Question 6.

 Column ‘A’ Column ‘B’ (1) IT Act 2000 (A) Provide legal recognition for transactions carried out by means of electronic data interchange (2) Digital Signature (B) Electronic Signature

 Column ‘A’ Column ‘B’ (1) IT Act 2000 (A) Provide legal recognition for transactions carried out by means of electronic data interchange (2) Digital Signature (B) Electronic Signature

Question 1.
What is Cyber Law?

1. Cyberlaw is the area of law that deals with the Internet’s relationship to technological and electronic elements.
2. Cyberlaw is the part of the overall legal system that deals with the Internet, cyberspace, and their respective legal issues.
3. Cyberlaw covers a fairly broad area, encompassing several subtopics including freedom of expression, access to and usage of the Internet, and online privacy

Question 2.
State the advantages of Cyber Law.

1. The Information Technology Act 2000 attempts to change outdated laws and provides ways to deal with cybercrimes.
2. The Information Technology Act offers the much-needed legal framework so that information is not denied.
3. The Information Technology Act has also proposed a legal framework for the authentication and origin of electronic records.

Question 3.
Define Ethics and Morals.

1. Ethics is also called moral philosophy is the discipline concerned with what is morally good and bad, right or wrong.
2. Morals are the standards of behaviour; principles of right and wrong behaviour.
3. Thus Morals are dictated by society, culture, or religion.

Question 4.
What is Cyber Crime?

1. Computer Crime is alternatively referred to as Cybercrime.
2. Computer crime is an act performed by a knowledgeable computer user, sometimes referred to as a Hacker.
3. A Hacker who illegally browses or steals a company’s or individual’s private information.
4. Cybercrimes can involve criminal activities that are traditional in nature, such as theft, fraud, forgery, defamation, and mischief.

Question 5.
State the examples of Cyber Crime.

1. Software piracy is nothing but copyright violation of software created originally by an individual or an institution.
2. Software piracy includes stealing codes/programs and other information illegally and creating the imitated copy by unauthorized means.
3. Gaining access without the users’ permission is known as unauthorized access.
4. Authorization means granting access rights to resources.
5. A copyright is a legal right that gives the creator of a literary, artistic, musical, or other creative work.
6. Copyright owners have the right to control the reproduction of their work, including the right to receive the royalty payment for that reproduction.
7. Activity such as decipher codes or passwords and breaking security systems for illegal reasons is called cracking.
8. The cracker will use a program or script known as a Crack.
9. Cyberstalking is a criminal practice where an individual uses the Internet to systematically harass or threaten someone.
10. Phishing is a technique of extracting confidential information such as credit card numbers and username password combos by pretending as a legal enterprise.
11. Phishing is typically carried out by email spoofing.
12. Plagiarism is presenting someone else’s work or idea as your own without their consent.
13. Hacking refers to unauthorized intrusion into a computer or a network.
14. Hacker is a person intensely interested in the deep and hidden or concealed working of any computer operating system and programming language.

Question 6.
Explain Security Procedures.

1. Encryption is a method of converting the original message into random text.
2. The full form of SSL is Secure Socket Layer.
3. Through the Secure Socket Layer, the transmission of data is encrypted.
4. A firewall refers to a network security (Hardware and Software) system which blocks certain types of information.

Question 7.
Discuss the IT Act of India 2000 and its features.

1. Information Technology Act, 2000 is an Act to provide legal recognition for transactions carried out by means of electronic data interchange and other means of electronic communication.
2. Information Technology Act, 2000 aims to provide the legal infrastructure for E-Commerce in India.
3. Cyber Laws have a major impact on e-businesses and the new economy in India.
4. The Information Technology Act, 2000 also aims to provide for the legal framework.
5. Digital signature has been replaced with electronic signature to make it a more technology-neutral act.

## Maharashtra Board Class 11 Information Technology Important Questions Chapter 3 Impressive Web Designing

Balbharati Maharashtra State Board Class 11 Information Technology Important Questions Chapter 3 Impressive Web Designing Important Questions and Answers.

## Maharashtra State Board 11th Information Technology Important Questions Chapter 3 Impressive Web Designing

1. Fill in the Blanks.

Question 1.
___________ resources have become a part of our day to day life.
Online

Question 2.
The ___________ is a powerful media to transmit information.
Internet

Question 3.
The pages of information displayed on the internet are referred to as ___________
Web Pages

Question 4.
The standards and formats for presenting text and graphics on the internet are developed and approved by ___________ governing authorities.
World Wide Web

Question 5.
The growing demand for attractive presentation of information using electronic means gave rise to the invention of ___________
Websites

Question 6.
WWW stands for ___________
World Wide Web

Question 7.
WWW stands for world wide web normally referred to as ___________
Web

Question 8.
___________ is a simple text file created using HTML.
Webpage

Question 9.
___________ is a collection of interlinked web pages containing text, images, audio and videos.
Website

Question 10.
A ___________ is a software used to view web pages or websites available on the internet.
Web browser

Question 11.
A ___________ is an application or a computer that sends webpages over the internet using the HTTP protocol.
Web Server I

Question 12.
The functionality of website is managed by ___________
Webserver

Question 13.
Full form of URL is ___________
Uniform Resource Locator

Question 14.
___________ is an address of a web page on the internet.
Uniform Resource Locator

Question 15.
The web pages are retrieved from the original location with the help of ___________
Uniform Resource Locator

Question 16.
Full form of HTTP is ___________
HyperText Transfer Protocol

Question 17.
___________ is a protocol used by WWW for client server communication.
Hyper Text Transfer Protocol

Question 18.
Full for of HTML is ___________
Hyper Text Markup Language

Question 19.
___________ enables to write code for a webpage.
HyperText Markup Language

Question 20.
All the webpages in a website are linked with one another, with the help of ___________ links.
Hypertext

Question 21.
___________ is a standard language for developing and creating interactive websites, introduced by Tim Berners Lee.
HyperText Markup Language

Question 22.
___________ documents are created in any text editor for and can be run(executed) on any computer that has a web browser.
HyperText Markup Language

Question 23.
___________ is compatible with most of the web browsers.
Hyper Text Markup Language

Question 24.
___________ Tags are also called paired tags.
Container

Question 25.
___________ Tags have a beginning tag and an end tag.
Container

Question 26.
___________ Tags are standalone tags and do not have an end tag.
Empty

Question 27.
___________ defines a header for a document or a section.

Question 28.
<nav>

Question 29.
___________ defines a section in a document.
<section>

Question 30.
___________ defines an independent self-contained article.
<article>

Question 31.
___________ defines content apart from the content (like a sidebar).
<aside>

Question 32.
___________ defines a footer for a document or a section.
<footer>

Question 33.
<details>

Question 34.
_________ formatting is used to make a document look attractive thereby enhancing its appearance.
Text

Question 35.
_________ displays text within it in Bold like Hello.
<b>

Question 36.
_________ displays text within it in italicized manner like Hello.
<i>

Question 37.
_________ displays text with underline like Hello.
<u>

Question 38.
_________ displays text in small font size.
<small>

Question 39.
_________ displays text in subscript form.
<sub>

Question 40.
___________ displays text in superscript form.
<sup>

Question 41.
The HTML ___________ element defines marked or highlighted text.
<mark>

Question 42.
HTML provides ___________ levels of heading tags.
Six

Question 43.
The ___________ tag displays text in bold and with largest heading level.
<H1>

Question 44.
The ___________ tag displays text in the smallest heading level.
<H6>

Question 45.
___________ tag is used to insert an image within a webpage.
<IMG>

Question 46.
___________ is used to specify the path of an image file.
src

Question 47.
___________ specifies height of the image in pixels.
Height

Question 48.
___________ specifies width of the image in pixels.
Width

Question 49.
___________ is referred as alternate text.
Alt

Question 50.
___________ is a empty tag.
<IMG>

Question 51.
___________ tag is used to display horizontal ruled line.
<hr>

Question 52.
___________ sets color for the horizontal ruled line.
color

Question 53.
___________ specifies the length of the ruled line in % or pixels.
width

Question 54.
___________ sets thickness of a ruled line.
size

Question 55.
___________ tag is used to define paragraphs.
<P>

Question 56.
A ___________ is made up of rows and columns.
Table

Question 57.
___________ is used to indicate creation of a table.
<table>

Question 58.
___________ is used to specify a table heading.
<caption>

Question 59.
___________ tag is used to create each row of the table.
<tr>

Question 60.
<th>

Question 61.
___________ specifies data within the table (cell content).
<td>

Question 62.
___________ attribute is required to display a border for the entire table.
border

Question 63.
___________ displays border in a specific color.
bordercolor

Question 64.
___________ the table either to the left, right or center.
aligns

Question 65.
___________ sets the background color for the table.
bgcolor

Question 66.
___________ are used to connect one document with another document.

Question 67.
In HTML, Links are created by using ___________ tag.
<a>

Question 68.
A ___________ by default appears blue in colour with an underline.

Question 69.
An ___________ link is underlined and purple.
Visited

Question 70.
A ___________ link is underlined and blue.
Active

Question 71.
___________ in HTML is used to accept user input.
Forms

Question 72.
A ___________ is a collection of different elements also called as controls.
Form

Question 73.
___________ attributes specifies a name to a form.
Name

Question 74.
The ___________ attribute specifies the path where the form is to be submitted.
Action

Question 75.
The ___________ attribute specifies the get or post method to be used when submitting the form data.
Method

Question 76.
The default method of submitting form data is ___________
GET

Question 77.
The data submitted by using ___________ is visible in the address bar.
GET

Question 78.
The ___________ method of sending data does not display the form data in the address bar.
POST

Question 79.
<Input type = “text”> creates a one line ___________
Textbox

Question 80.
<Input type = “radio”> creates a ___________ button.

Question 81.
The ___________ button allows one option selection against multiple choices.

Question 82.
<Input type = “checkbox”> creates a ___________
Checkbox

Question 83.
___________ allows more than one selection against multiple choices.
Checkbox

Question 84.
<Input type = “submit”> displays a button for ___________ the form data to a server.
Submitting

Question 85.
The ___________ type is used to create text contents in the form of ‘ * ‘ asterik or ‘ . ‘ disc.

Question 86.
The ___________ control clears the text content entered in the form.
Reset

Question 87.
<Input type =”____________”> displays push button which activates on events.
Button

Question 88.
_________ describes, the name of the control like text radio.
Type

Question 89.
The ___________ attribute is a user defined value.
Name

Question 90.
The ___________ attribute is used with text and password type.
Max length

Question 91.
___________ specifies the maximum number of characters that can be entered in a text or password box.
Max length

Question 92.
The ___________ attribute can be used with text and password type.
Size

Question 93.
___________ specifies the width of the text box.
Size

Question 94.
The ___________ attribute specifies the default selection for options in a checkbox or radio button.
Checked

Question 95.
The ___________ attribute can be used with text, checkbox, radio, submit or reset.
Value

Question 96.
The ___________ tag is used to create a textbox with multiple lines.
<textarea>

Question 97.
___________ is used to specify name for the text area.
Name

Question 98.
___________ specifies the number of lines in a text area.
Rows

Question 99.
___________ specifies the width of a text area.
Cols

Question 100.
___________ specifies the maximum number of characters allowed in the textarea.
Max length

Question 101.
___________ specifies a short hint that describes the expected value of a textarea.
Placeholder

Question 102.
___________ specifies that textarea must be filled out. i.e. It can not be blank.
Required

Question 103.
___________ tag is used to create drop-down list.
<select>

Question 104.
___________ assigns name to the control.
Name

Question 105.
___________ allows the user to select more than one value.
Multiple

Question 106.
The ___________ attribute is used to specify the number of visible values.
Size

Question 107.
To define preselected option, ‘___________’ attribute is added to the <option>.
Selected

Question 108.
___________ assigns value to the option specified in the dropdown list.
Value

Question 109.
___________ was initially created to make webpages alive.
JavaScript

Question 110.
A ___________ is a list of commands that are executed by a scripting engine.
Script

Question 111.
___________ are used to generate dynamic Web pages on the Web.
Scripts

Question 112.
___________ can be use for client side or server side scripting language.
JavaScript

Question 113.
___________ code can be inserted in HTML program between <script> and </script> tag.
JavaScript

Question 114.
___________ attribute is used to set scripting language.
Language

Question 115.
The ___________ is a basic unit of storage in a JavaScript program.
Variable

Question 116.
___________ name may consist of alphabets, digits and underscore and dollar character with following rules.
Variable

Question 117.
Standard keywords are not allowed as ___________ name.
Variable

Question 118.
___________ name can be limited up to 255 characters.
Variable

Question 119.
___________ name in javascript is declared with keyword ‘var’.
Variable

Question 120.
_____________ provides data types to store and use different types of values.
JavaScript

Question 121.
Numerical value specially belongs to the ‘___________’ data type.
Number

Question 122.
___________ data type can hold positive as well as negative values.
Number

Question 123.
___________ are used for storing text.
Strings

Question 124.
___________ type represents only two values ‘true’ and ‘false’.
Boolean

Question 125.
JavaScript returns ‘___________’ when variable which is declared but not assigned.
Undefined

Question 126.
___________ are used to do arithmetic and logical operations.
Operators

Question 127.
Operators that require one operand is called as ___________ operator.
Unary

Question 128.
Operators that require two operands are called as ___________ operator.
Binary

Question 129.
___________ operators are used in mathematical expressions.
Arithmetic

Question 130.
It is important to know that ___________ operator is not ‘equal to’ operator.
Assignment

Question 131.
___________ operator is used to assign value of an expression to a variable.
Assignment

Question 132.
___________ operators are used to check conditions or comparison of operands.
Relational

Question 133.
___________ operators are used to verifying more than one condition at a time or to negate the condition.
Logical

Question 134.
___________ (++) operator in JavaScript is used to increment value of variable by one.
Increment

Question 135.
___________ operator in JavaScript is used to decrement value of variable by one.
Decrement

Question 136.
___________ are non-executable statements in program.

Question 137.
___________ are used to provide information or explanation about your programming construct.

Question 138.
Statements added in ___________ are ignored by JavaScript.

Question 139.
___________ is used to perform repetitive tasks whenever required.
Function

Question 140.
___________ is reusable code block that will be executed when it is called.
Function

Question 141.
___________ function is used to parse a string and convert it into a number.
parseInt()

Question 142.
___________ function is used to parse a string and convert it into floating point representation.
parseFloat()

Question 143.
___________ function displays alert popup box with ok button. This is also called as a message box.

Question 144.
___________ function is used when you want input value from user at the time of program execution.
prompt()

Question 145.
___________ function displays confirmation message box with ok and cancel button.
confirm()

Question 146.
___________ string function used to convert the given string into lower case alphabets.
toLowerCase()

Question 147.
___________ string function is used to convert given string into uppercase alphabets.
toUpperCase()

Question 148.
___________ returns ‘true’ if given value is not a number. It returns ‘false’ if given value is number.
isNaN()

Question 149.
A ___________ in any scripting and programming language is a small part of a program that we require again and again.
Function

Question 150.
A ___________ is a subprogram designed to perform a particular task.
Function

Question 151.
___________ can be called either by an event or by giving call to that function.
Functions

Question 152.
___________ is an event-driven language.
JavaScript

Question 153.
___________ is an action done bv the user or an application.
Event

Question 154.
___________ lets you execute a code when events are detected.
JavaScript

Question 155.
___________ when user moves the mouse away from an element.
onMouseOut

Question 156.
___________ when user clicks an element.
onClick

Question 157.
___________ when user moves the mouse over an element.
onMouseOver

Question 158.
___________ when user releases a mouse button over an element.
onMouseUp

2. True or False.

Question 1.
Online resources have become a part of our day-to-day life.
True

Question 2.
The Internet is a powerful medium to transmit information.
True

Question 3.
The pages of the information displayed on the internet are referred to as the worldwide web.
False

Question 4.
The standards and formats for presenting text and graphics on the internet are developed and approved by Webpages governing authorities.
False

Question 5.
The growing demand for attractive presentation of information using electronic means gave rise to the invention of Websites.
True

Question 6.
WWW stands for world wide web.
True

Question 7.
WWW stands for world wide web normally referred to as Webpage.
False

Question 8.
The web is a simple text file created using HTML.
False

Question 9.
A website is a collection of interlinked web pages containing text, images, audio, and videos.
True

Question 10.
A web browser is software used to view web pages or websites available on the internet.
True

Question 11.
A Web server is an application or a computer that sends webpages over the internet using the HTTP protocol.
True

Question 12.
The functionality of the website is managed by Uniform Resource Locator.
False

Question 13.
The full form of URL is Uniform Resource Locator.
True

Question 14.
Uniform Resource Locator is an address of a web page on the internet.
True

Question 15.
The web pages are retrieved from the original location with the help of Uniform Resource Locator.
True

Question 16.
The full form of HTTP is HyperText Transfer Protocol.
True

Question 17.
Uniform Resource Locator is a protocol used by WWW for client-server communication.
False

Question 18.
Full form of HTML is HyperText Markup Language.
True

Question 19.
HyperText Markup Language enables to write code for a webpage.
True

Question 20.
All the webpages in a website are linked with one another, with the help of HyperText links.
True

Question 21.
HyperText Markup Language is a standard language for developing and creating interactive websites, introduced by Tim Berners Lee.
True

Question 22.
Uniform Resource Locator documents are created in any text editor and can be run(executed) on any computer that has a web browser.
False

Question 23.
HyperText Markup Language is compatible with most web browsers.
False

Question 24.
Empty Tags are also called paired tags.
False

Question 25.
Container Tags have a beginning tag and an end tag.
True

Question 26.
Container Tags are standalone tags and do not have an end tag.
False

Question 27.
<nav> defines a header for a document or a section.
False

Question 28.
False

Question 29.
<article> defines a section in a document.
False

Question 30.
<section> defines an independent self-contained article.
False

Question 31.
<aside> defines content apart from the content (like a sidebar).
True

Question 32.
<footer> defines a footer for a document or a section.
True

Question 33.
True

Question 34.
<b> formatting is used to make a document look attractive thereby enhancing its appearance.
False

Question 35.
<b> displays text within it in Bold like Hello.
True

Question 36.
<i> display text within it in an italicized manner like Hello.
True

Question 37.
<u> displays text with an underline like Hello.
True

Question 38.
<small> displays text in small font size.
True

Question 39.
Text displays text in subscript form.
False

Question 40.
<sup> displays text in superscript form.
True

Question 41.
The HTML <sub> element defines marked or highlighted text.
False

Question 42.
HTML provides six levels of heading tags.
True

Question 43.
The Six tag displays text in bold and with the largest heading level.
False

Question 44.
The <H6> tag displays text in the smallest heading level.
True

Question 45.
src tag is used to insert an image within a webpage.
False

Question 46.
<IMG> is used to specify the path of an image file.
False

Question 47.
Height specifies the height of the image in pixels.
True

Question 48.
Width specifies the width of the image in pixels.
True

Question 49.
Alt is referred to as alternate text.
True

Question 50.
<IMG> is a empty tag.
True

Question 51.
<P> tag is used to display horizontal ruled line.
False

Question 52.
color sets the color for the horizontal ruled line.
True

Question 53.
width specifies the length of the ruled line in % or pixels.
True

Question 54.
size sets the thickness of a ruled line.
True

Question 55.
<hr> tag is used to define paragraphs.
False

Question 56.
A Table is made up of rows and columns.
True

Question 57.
<caption> is used to indicate the creation of a table.
False

Question 58.
<table> is used to specify a table heading.
False

Question 59.
<tr> tag is used to create each row of the table.
True

Question 60.
False

Question 61.
<td> specifies data within the table (cell content).
True

Question 62.
A border attribute is required to display a border for the entire table.
True

Question 63.
bgcolor displays borders in a specific color.
False

Question 64.
border the table either to the left, right or center.
False

Question 65.
bgcolor sets the background color for the table.
True

Question 66.
Hyperlinks are used to connect one document with another document.
True

Question 67.
In HTML, links are created by using <a> tag.
True

Question 68.
A Hyperlink by default appears blue in colour with an underline.
True

Question 69.
An Active link is underlined and purple.
False

Question 70.
A Visited link is underlined and blue.
False

Question 71.
Forms in HTML are used to accept user input.
True

Question 72.
A Form is a collection of different elements also called controls.
True

Question 73.
Name attributes specifies a name to a form.
True

Question 74.
The Method attribute specifies the path where the form is to be submitted.
False

Question 75.
The Action attribute specifies the get or post method to be used when submitting the form data.
False

Question 76.
The default method of submitting form data is GET.
True

Question 77.
The data submitted by using POST is visible in the address bar.
False

Question 78.
The GET method of sending data does not display the form data in the address bar.
False

Question 79.
<Input type = “text”> creates a one line Textbox.
True

Question 80.
True

Question 81.
The radio button allows one option selection against multiple choices.
True

Question 82.
<Input type = “checkbox”> creates a Password.
False

Question 83.
The button allows more than one selection against multiple choices.
False

Question 84.
<Input type = “submit”> displays a button for Submitting the form data to a server.
True

Question 85.
The Checkbox input type is used to create text contents in the form of ‘*’ asterisk or ‘•’ disc.
False

Question 86.
The Reset control clears the text content entered in the form.
True

Question 87.
<Input type = “Radio”> displays push button which activates on events.
False

Question 88.
Maxlength describes the name of the control like text radio.
False

Question 89.
The Name attribute is a user-defined value.
True

Question 90.
Maxlength attribute is used with text and password type.
True

Question 91.
Type specifies the maximum number of characters that can be entered in a text or password box.
False

Question 92.
The ‘Size’ attribute can be used with text and password type.
True

Question 93.
The value specifies the width of the text box.
False

Question 94.
The ‘Checked’ attribute specifies the default selection for options in a checkbox or radio button.
True

Question 95.
The ‘Size’ attribute can be used with text, checkbox, radio, submit or reset.
False

Question 96.
The <textarea> tag is used to create a textbox with multiple lines.
True

Question 97.
Name is used to specify a name for the textarea.
True

Question 98.
Required specifies the number of lines in a text area.
False

Question 99.
Maxlength specifies the width of a text area.
False

Question 100.
Maxlength specifies the maximum number of characters allowed in the textarea.
True

Question 101.
Placeholder specifies a short hint that describes the expected value of a textarea.
True

Question 102.
Rows specify that textarea must be filled out. i.e. It can not be blank.
False

Question 103.
Value tag is used to create a drop-down list.
False

Question 104.
Name assigns a name to the control.
True

Question 105.
Multiple allows the user to select more than one value.
True

Question 106.
The Size attribute is used to specify the number of visible values.
True

Question 107.
To define the preselected option, the ‘Selected’ attribute is added to the <option>.
True

Question 108.
<select> assigns value to the option specified in the dropdown list.
False

Question 109.
JavaScript was initially created to make web pages alive.
True

Question 110.
A Script is a list of commands that are executed by a scripting engine.
True

Question 111.
Scripts are used to generate dynamic Web pages on the Web.
True

Question 112.
JavaScript can be used for the client-side or server-side scripting languages.
True

Question 113.
Python code can be inserted in HTML program between <script> and </script> tag.
False

Question 114.
The language attribute is used to set scripting language.
True

Question 115.
A Variable is a basic unit of storage in a JavaScript program.
True

Question 116.
The variable name may consist of alphabets, digits and underscore, and dollar characters with the following rules.
True

Question 117.
Standard keywords are not allowed as Variable names.
True

Question 118.
A variable names can be limited to up to 255 characters.
True

Question 119.
Variable name in javascript is declared with keyword var’.
True

Question 120.
JavaScript provides data types to store and use different types of values.
True

Question 121.
Numerical value specially belongs to the ‘Boolean’ data type.
False

Question 122.
The number data type can hold positive as well as negative values.
True

Question 123.
Strings are used for storing text.
True

Question 124.
Number type represents only two values ‘true’ and ‘false’.
False

Question 125.
JavaScript returns ‘Undefined’ when a variable is declared but not assigned.
True

Question 126.
Operators are used to doing arithmetic and logical operations.
True

Question 127.
Operators that require one operand is called as Unary operator.
True

Question 128.
Operators that require two operands are called Binary operators.
True

Question 129.
Assignment operators are used in mathematical expressions.
False

Question 130.
It is important to know that the Assignment operator is not an ‘equal to’ operator.
True

Question 131.
The binary operator is used to assign the value of an expression to a variable.
False

Question 132.
Relational operators are used to checking conditions or comparisons of operands.
True

Question 133.
Logical operators are used to verifying more than one condition at a time or to negate the condition.
True

Question 134.
The decrement (++) operator in JavaScript is used to increment the value of a variable by one.
False

Question 135.
The increment operator in JavaScript is used to decrement the value of variables by one.
False

Question 136.
Mistakes are non-executable statements in the program.
False

Question 137.
True

Question 138.
True

Question 139.
The function is used to perform repetitive tasks whenever required.
True

Question 140.
The function is a reusable code block that will be executed when it is called.
True

Question 141.
parseFloat() function is used to parse a string and convert it into a number.
False

Question 142.
parselnt() function is used to parse a string and convert it into floating-point representation.
False

Question 143.
alert() function displays an alert popup box with an ok button. This is also called a message box.
False

Question 144.
prompt() function is used when you want input value from the user at the time of program execution.
True

Question 145.
confirm() function displays a confirmation message box with ok and cancel buttons.
True

Question 146.
toUpperCase() string function used to convert the given string into lower case alphabets.
False

Question 147.
toLowerCase() string function is used to convert given string into uppercase alphabets.
False

Question 148.
isNaN() returns ‘true’ if given value is not a number. It returns ‘false’ if the given value is a number.
True

Question 149.
A Gmail in any scripting and programming language is a small part of a program that we require again and again.
False

Question 150.
A Function is a subprogram designed to perform a particular task.
True

Question 151.
Functions can be called either by an event or by giving a call to that function.
True

Question 152.
JavaScript is an event-driven language.
True

Question 153.
An event is an action done by the user or an application.
True

Question 154.
JavaScript lets you execute a code when events are detected.
True

Question 155.
onMouseUp when the user moves the mouse away from an element.
False

Question 156.
onClick when the user clicks an element.
True

Question 157.
onMouseOver when the user moves the mouse over an element.
True

Question 158.
onClick when the user releases a mouse button over an element.
False

3. Multiple Choice Question (Single Choice)

Question 1.
__________ resources have become a part of our day to day life.
(A) Online
(B) Internet
(C) Webpages
(D) World Wide Web
(A) Online

Question 2.
The __________ is a powerful media to transmit information.
(A) Online
(B) Internet
(C) Webpages
(D) World Wide Web
(B) Internet

Question 3.
The pages of information displayed on the internet are referred to as __________
(A) Online
(B) Internet
(C) Webpages
(D) World Wide Web
(C) Web pages

Question 4.
The standards and formats for presenting text and graphics on the internet are developed and approved by __________ governing authorities.
(A) Online
(B) Internet
(C) Webpages
(D) World Wide Web
(D) World Wide Web

Question 5.
The growing demand for attractive presentation of information using electronic means gave rise to the invention of __________
(A) Online
(B) Internet
(C) Webpages
(D) Websites
(D) Websites

Question 6.
WWW stands for __________
(A) World Wide Web
(B) Webpage
(C) Website
(D) Web Browser
(A) World Wide Web

Question 7.
WWW stands for world wide web normally referred to as __________
(A) World Wide Web
(B) Webpage
(C) Website
(D) Web
(D) Web

Question 8.
__________ is a simple text file created using HTML.
(A) World Wide Web
(B) Webpage
(C) Website
(D) Web
(B) Webpage

Question 9.
__________ is a collection of interlinked web pages containing text, images, audio and videos.
(A) World Wide Web
(B) Webpage
(C) Website
(D) Web
(C) Website

Question 10.
A __________ is a software used to view web pages or websites available on the internet.
(A) World Wide Web
(B) Webpage
(C) Website
(D) Web Browser
(D) Web Browser

Question 11.
A __________ is an application or a computer that sends webpages over the internet using the HTTP protocol.
(A) Webserver
(B) Uniform Resource Locator
(C) HyperText Transfer Protocol
(D) Hypertext
(A) Web Server

Question 12.
The functionality of website is managed by __________
(A) Webserver
(B) Uniform Resource Locator
(C) Hyper Text Transfer Protocol
(D) Hypertext
(A) Webserver

Question 13.
Full form of URL is __________
(A) Uniform Resource Locator
(B) United Research Live
(C) Uniform Research Live
(D) Uniform Research Locator
(A) Uniform Resource Locator

Question 14.
__________ is an address of a web page on the internet.
(A) Web Server
(B) Uniform Resource Locator
(C) Hyper Text Transfer Protocol
(D) Hypertext
(B) Uniform Resource Locator

Question 15.
The web pages are retrieved from the original location with the help of __________
(A) Web Server
(B) Uniform Resource Locator
(C) Hyper Text Transfer Protocol
(D) Hypertext
(B) Uniform Resource Locator

Question 16.
Full form of HTTP is __________
(A) Hyper Text Transfer Protocol
(B) Hyper Test Transfer Protocol
(C) Hyper Text Transfer Permission
(D) Hyper Text Transfer Permission
(A) Hyper Text Transfer Protocol

Question 17.
__________ is a protocol used by WWW for client-server communication.
(A) Web Server
(B) Uniform Resource Locator
(C) Hyper Text Transfer Protocol
(D) Hyper Text
(C) Hyper Text Transfer Protocol

Question 18.
Full form of HTML is __________
(A) Hyper Text Markup Language
(B) Hyper Test Markup Language
(C) Hyper Text Machine Language
(D) Hyper Test Machine Language
(A) Hyper Text Markup Language

Question 19.
__________ enables to write code for a webpage.
(A) Webserver
(B) Uniform Resource Locator
(C) Hyper Text Transfer Protocol
(D) Hyper Text Markup Language
(D) Hyper Text Markup Language

Question 20.
All the webpages in a website are linked with one another, with the help of __________ links.
(A) Webserver
(B) Uniform Resource Locator
(C) HyperText Transfer Protocol
(D) Hypertext
(D) Hypertext

Question 21.
__________ is a standard language for developing and creating interactive websites, introduced by Tim Berners Lee.
(A) Web server
(B) Uniform Resource Locator
(C) Hyper Text Transfer Protocol
(D) Hyper Text Markup Language
(D) Hyper Text Markup Language

Question 22.
__________ documents are created in any text editor for and can be run (executed) on any computer that has a web browser.
(A) Webserver
(B) Uniform Resource Locator
(C) Hyper Text Transfer Protocol
(D) Hyper Text Markup Language
(D) Hyper Text Markup Language

Question 23.
__________ is compatible with most of the web browsers.
(A) Web server
(B) Uniform Resource Locator
(C) HyperText Transfer Protocol
(D) HyperText Markup Language
(D) Hyper Text Markup Language

Question 24.
__________ Tags are also called paired tags.
(A) Container
(B) Empty
(C) Web Server
(D) Uniform Resource Locator
(A) Container

Question 25.
__________ Tags have a beginning tae and an end tag.
(A) Container
(B) Empty
(C) Web Server
(D) Uniform Resource Locator
(A) Container

Question 26.
__________ Tags are standalone tags and do not have an end tag.
(A) Container
(B) Empty
(C) Web Server
(D) Uniform Resource Locator
(B) Empty

Question 27.
__________ defines a header for a document or a section.
(B) <nav>
(C) <section>
(D) <article>

Question 28.
(B) <nav>
(C) <section>
(D) <article>
(B) <nav>

Question 29.
__________ defines a section in a document.
(B) <nav>
(C) <section>
(D) <article>
(C) <section>

Question 30.
__________ defines an independent self-contained article.
(B) <nav>
(C) <section>
(D) <article>
(D) <article>

Question 31.
__________ defines content apart from the content (like a sidebar).
(A) <aside>
(B) <footer>
(C) <details>
(A) <aside>

Question 32.
__________ defines a footer for a document or a section.
(A) <aside>
(B) <footer>
(C) <details>
(B) <footer>

Question 33.
(A) <aside>
(B) <footer>
(C) <details>
(C) <details>

Question 34.
__________ formatting is used to make a document look attractive thereby enhancing it’s appearance.
(A) Text
(B) <b>
(C) <i>
(D) <u>
(A) Text

Question 35.
__________ displays text within it in Bold like Hello.
(A) Text
(B) <b>
(C) <i>
(D) <u>
(B) <b>

Question 36.
__________ displays text within it in italicized manner like Hello.
(A) Text
(B) <b>
(C) <i>
(D) <u>
(C) <i>

Question 37.
__________ displays text with underline like Hello.
(A) Text
(B) <b>
(C) <i>
(D) <u>
(D) <u>

Question 38.
__________ displays text in small font size.
(A) <small>
(B) <sub>
(C) <sup>
(D) <mark>
(A) <small>

Question 39.
__________ displays text in subscript form.
(A) <small>
(B) <sub>
(C) <sup>
(D) <mark>
(B) <sub>

Question 40.
__________ displays text in superscript form.
(A) <small>
(B) <sub>
(C) <sup>
(D) <mark>
(C) <sup>

Question 41.
The HTML __________ element defines marked or highlighted text.
(A) <small>
(B) <sub>
(C) <sup>
(D) <mark>
(D) <mark>

Question 42.
HTML provides __________ levels of heading tags.
(A) Six
(B) <H1>
(C) <H6>
(D) <H2>
(A) Six

Question 43.
The __________ tag displays text in bold and with largest heading level.
(A) Six
(B) <H1>
(C) <H6>
(D) <H2>
(B) <H1>

Question 44.
The __________ tag displays text in the smallest heading level.
(A) Six
(B) <H1>
(C) <H6>
(D) <H2>
(C) <H6>

Question 45.
__________ tag is used to insert an image within a webpage.
(A) <IMG>
(B) src
(C) Height
(D) Width
(A) <IMG>

Question 46.
__________ is used to specify the path of an image file.
(A) <IMG>
(B) src
(C) Height
(D) Width
(B) src

Question 47.
__________ specifies height of the image in pixels.
(A) <IMG>
(B) src
(C) Height
(D) Width
(C) Height

Question 48.
__________ specifies width of the image in pixels.
(A) <IMG>
(B) src
(C) Height
(D) Width
(D) Width

Question 49.
__________ is referred as alternate text.
(A) Alt
(B) <IMG>
(C) <hr>
(D) color
(A) Alt

Question 50.
__________ is a empty tag.
(A) Alt
(B) <IMG>
(C) <hr>
(D) color
(B) <IMG>

Question 51.
__________ tag is used to display horizontal ruled line.
(A) Alt
(B) <IMG>
(C) <hr>
(D) color
(C) <hr>

Question 52.
__________ sets color for the horizontal ruled line.
(A) Alt
(B) <IMG>
(C) <hr>
(D) color
(D) color

Question 53.
__________ specifies the length of the ruled line in % or pixels.
(A) width
(B) size
(C) <P>
(D) color
(A) width

Question 54.
__________ sets thickness of a ruled line.
(A) width
(B) size
(C) <P>
(D) color
(B) size

Question 55.
__________ tag is used to define paragraphs.
(A) width
(B) size
(C) <P>
(D) color
(C) <P>

Question 56.
A __________ is made up of rows and columns.
(A) Table
(B) <caption>
(C) <tr>
(D) <th>
(A) Table

Question 57.
__________ is used to indicate creation of a table.
(A) <table>
(B) <caption>
(C) <tr>
(D) <th>
(A) <table>

Question 58.
__________ is used to specify a table heading.
(A) <table>
(B) <caption>
(C) <tr>
(D) <th>
(B) <caption>

Question 59.
__________ tag is used to create each row of the table.
(A) <table>
(B) <caption>
(C) <tr>
(D) <th>
(C) <tr>

Question 60.
(A) <table>
(B) <caption>
(C) <tr>
(D) <th>
(D) <th>

Question 61.
__________ specifies data within the table (cell content).
(A) <table>
(B) <caption>
(C) <tr>
(D) <td>
(D) <td>

Question 62.
__________ attribute is required to display a border for the entire table.
(A) border
(B) bordercolor
(C) aligns
(D) bgcolor
(A) border

Question 63.
__________ displays border in a specific color.
(A) border
(B) bordercolor
(C) aligns
(D) bgcolor
(B) bordercolor

Question 64.
__________ the table either to the left, right or center.
(A) border
(B) bordercolor
(C) aligns
(D) bgcolor
(C) aligns

Question 65.
__________ sets the background color for the table.
(A) border
(B) bordercolor
(C) aligns
(D) bgcolor
(D) bgcolor

Question 66.
__________ are used to connect one document with another document.
(B) <a>
(C) Hypertext
(D) Visited

Question 67.
In HTML, Links are created bv usinsr __________ tag.
(A) Hypertext
(B) <a>
(D) Visited
(B) <a>

Question 68.
A __________ by default appears blue in colour with an underline.
(A) Hypertext
(B) <a>
(D) Visited

Question 69.
A __________ link is underlined and purple.
(A) Hypertext
(B) <a>
(D) Visited
(D) Visited

Question 70.
An __________ link is underlined and blue.
(A) Hypertext
(B) <a>
(D) Active
(D) Active

Question 71.
__________ in HTML is used to accept user input.
(A) Forms
(B) Action
(C) Method
(D) GET
(A) Forms

Question 72.
A __________ is a collection of different elements also called as controls.
(A) Form
(B) Action
(C) Method
(D) GET
(A) Form

Question 73.
__________ attributes specifies a name to a form.
(A) Name
(B) Action
(C) Method
(D) GET
(A) Name

Question 74.
The __________ attribute specifies the path where the form is to be submitted.
(A) Name
(B) Action
(C) Method
(D) GET
(B) Action

Question 75.
The __________ attribute specifies the get or post method to be used when submitting the form data.
(A) Name
(B) Action
(C) Method
(D) GET
(C) Method

Question 76.
The default method of submitting form data is __________
(A) Name
(B) Action
(C) Method
(D) GET
(D) GET

Question 77.
The data submitted by using __________ is visible in the address bar.
(A) Name
(B) Action
(C) Method
(D) GET
(D) GET

Question 78.
The __________ method of sending data does not display the form data in the address bar.
(A) POST
(B) Action
(C) Method
(D) GET
(A) POST

Question 79.
<Input type = “text”> creates a one line __________
(A) Textbox
(C) Checkbox
(D) Submitting
(A) Textbox

Question 80.
<Input type = “radio”> creates a __________ button.
(A) Textbox The
(C) Checkbox
(D) Submitting

Question 81.
The __________ button allows one option selection against multiple choices.
(A) Textbox
(C) Checkbox
(D) Submitting

Question 82.
<Input type =”checkbox”> creates a __________
(A) Textbox
(C) Checkbox
(D) Submitting
(C) Checkbox

Question 83.
__________ allows more than one selection against multiple choices.
(A) Textbox
(C) Checkbox
(D) Submitting
(C) Checkbox

Question 84.
<Input type = “submit”> displays a button for __________ the form data to a server.
(A) Textbox
(C) Checkbox
(D) Submitting
(D) Submitting

Question 85.
The __________ input type is used to create text contents in the form of ‘*’ asterik or ‘.’ disc.
(B) Reset
(C) Button
(D) Textbox

Question 86.
The __________ control clears the text content entered in the form.
(B) Reset
(C) Button
(D) Textbox
(B) Reset

Question 87.
<Input type = “___________”> displays push button which activates on events.
(B) Reset
(C) Button
(D) Textbox
(C) Button

Question 88.
__________ describes, the name of the control like text radio.
(A) Type
(B) Name
(C) Maxlength
(D) Size
(A) Type

Question 89.
The __________ attribute is a user defined value.
(A) Type
(B) Name
(C) Maxlength
(D) Size
(B) Name

Question 90.
__________ attribute is used with text and password type.
(A) Type
(B) Name
(C) Maxlength
(D) Size
(C) Maxlength

Question 91.
__________ specifies the maximum number of characters that can be entered in a text or password box.
(A) Type
(B) Name
(C) Maxlength
(D) Size
(C) Maxlength

Question 92.
The ‘___________’ attribute can be used with text and password type.
(A) Type
(B) Name
(C) Maxlength
(D) Size
(D) Size

Question 93.
__________ specifies the width of the text box.
(A) Type
(B) Name
(C) Maxlength
(D) Size
(D) Size

Question 94.
The ‘______________’ attribute specifies the default selection for options in a checkbox or radio button.
(A) Checked
(B) Value
(C) Name
(D) Maxlength
(A) Checked

Question 95.
The ‘______________’ attribute can be used with text, checkbox, radio, submit or reset.
(A) Checked
(B) Value
(C) Name
(D) Maxlength
(B) Value

Question 96.
The __________ tag is used to create a textbox with multiple lines.
(A) <textarea>
(B) Name
(C) Rows
(D) Cols
(A) <textarea>

Question 97.
__________ is used to specify name for the textarea.
(A) <textarea>
(B) Name
(C) Rows
(D) Cols
(B) Name

Question 98.
__________ specifies the number of lines in a textarea.
(A) <textarea>
(B) Name
(C) Rows
(D) Cols
(C) Rows

Question 99.
__________ specifies the width of a text area.
(A) <textarea>
(B) Name
(C) Rows
(D) Cols
(D) Cols

Question 100.
__________ specifies the maximum number of characters allowed in the textarea.
(A) Maxlength
(B) Placeholder
(C) Required
(D) Rows
(A) Maxlength

Question 101.
__________ specifies a short hint that describes the expected value of a textarea.
(A) Maxlength
(B) Placeholder
(C) Required
(D) Rows
(B) Placeholder

Question 102.
__________ specifies that textarea must be filled out. i.e. It can not be blank.
(A) Maxlength
(B) Placeholder
(C) Required
(D) Rows
(C) Required

Question 103.
__________ tag is used to create drop-down list.
(A) <select>
(B) Name
(C) Multiple
(D) Size
(A) <select>

Question 104.
__________ assigns name to the control.
(A) <select>
(B) Name
(C) Multiple
(D) Size
(B) Name

Question 105.
__________ allows the user to select more than one value.
(A) <select>
(B) Name
(C) Multiple
(D) Size
(C) Multiple

Question 106.
The __________ attribute is used to specify the number of visible values.
(A) <select>
(B) Name
(C) Multiple
(D) Size
(D) Size

Question 107.
To define preselected option, ‘___________’ attribute is added to the <option>.
(A) Selected
(B) Value
(C) Multiple
(D) Size
(A) Selected

Question 108.
__________ assigns value to the option specified in the dropdown list.
(A) Selected
(B) Value
(C) Multiple
(D) Size
(B) Value

Question 109.
__________ was initially created to make webpages alive.
(A) JavaScript
(B) Script
(C) Language
(D) Python
(A) JavaScript

Question 110.
A __________ is a list of commands that are executed by a scripting engine.
(A) JavaScript
(B) Script
(C) Language
(D) Python
(B) Script

Question 111.
__________ are used to generate dynamic Web pages on the Web.
(A) JavaScript
(B) Scripts
(C) Language
(D) Python
(B) Scripts

Question 112.
__________ can be use for client side or server side scripting language.
(A) JavaScript
(B) Script
(C) Language
(D) Python
(A) JavaScript

Question 113.
__________ code can be inserted in HTML program between <script> and </script> tag.
(A) JavaScript
(B) Script
(C) Language
(D) Python
(A) JavaScript

Question 114.
__________ attribute is used to set scripting language.
(A) JavaScript
(B) Scrip
(C) Language
(D) Python
(C) Language

Question 115.
The __________ is a basic unit of storage in a JavaScript program.
(A) Variable
(B) Java
(C) .Net
(D) Python
(A) Variable

Question 116.
__________ name may consist of alphabets, digits and underscore and dollar character with following rules.
(A) Variable
(B) Java
(C) .Net
(D) Python
(A) Variable

Question 117.
Standard keywords are not allowed as __________ name.
(A) Variable
(B) Java
(C) .Net
(D) Python
(A) Variable

Question 118.
__________ name can be limited up to 255 characters.
(A) Variable
(B) Java
(C) .Net
(D) Python
(A) Variable

Question 119.
__________ name in javascript is declared with keyword ‘var’.
(A) Variable
(B) Java
(C) .Net
(D) Python
(A) Variable

Question 120.
__________ provides data types to store and use different types of values.
(A) JavaScript
(B) Number
(C) Strings
(D) Boolean
(A) JavaScript

Question 121.
Numerical value specially belongs to the ‘____________’ data type.
(A) JavaScript
(B) Number
(C) Strings
(D) Boolean
(B) Number

Question 122.
__________ data type can hold positive as well as negative values.
(A) JavaScript
(B) Number
(C) Strings
(D) Boolean
(B) Number

Question 123.
__________ are used for storing text.
(A) JavaScript
(B) Number
(C) Strings
(D) Boolean
(C) Strings

Question 124.
__________ type represents only two values ‘true’ and ‘false’.
(A) JavaScript
(B) Number
(C) Strings
(D) Boolean
(D) Boolean

Question 125.
JavaScript returns ‘____________’ when variable which is declared but not assigned.
(A) Undefined
(B) Number
(C) Strings
(D) Boolean
(A) Undefined

Question 126.
__________ are used to do arithmetic and logical operations.
(A) Operators
(B) Unary
(C) Binary
(D) Arithmetic
(A) Operators

Question 127.
Operators that require one operand is called as __________ operator.
(A) Operators
(B) Unary
(C) Binary
(D) Arithmetic
(B) Unary

Question 128.
Operators that require two operands are called as __________ operator.
(A) Operators
(B) Unary
(C) Binary
(D) Arithmetic
(C) Binary

Question 129.
__________ operators are used in mathematical expressions.
(A) Operators
(B) Unary
(C) Binary
(D) Arithmetic
(D) Arithmetic

Question 130.
It is important to know that __________ operator is not ‘equal to’ operator.
(A) Assignment
(B) Relational
(C) Logical
(D) Increment
(A) Assignment

Question 131.
__________ operator is used to assign value of an expression to a variable.
(A) Assignment
(B) Relational
(C) Logical
(D) Increment
(A) Assignment

Question 132.
__________ operators are used to check conditions or comparison of operands.
(A) Assignment
(B) Relational
(C) Logical
(D) Increment
(B) Relational

Question 133.
__________ operators are used to verifying more than one condition at a time or to negate the condition.
(A) Assignment
(B) Relational
(C) Logical
(D) Increment
(C) Logical

Question 134.
__________ (++) operator in JavaScript is used to increment value of variable by one.
(A) Assignment
(B) Relational
(C) Logical
(D) Increment
(D) Increment

Question 135.
__________ operator in JavaScript is used to decrement value of variable by one.
(A) Assignment
(B) Relational
(C) Logical
(D) Decrement
(D) Decrement

Question 136.
___________ are non-executable statements in program.
(B) Mistakes
(C) Java
(D) Python

Question 137.
___________ are used to provide information or explanation about your programming construct.
(B) Mistakes
(C) Java
(D) Python

Question 138.
Statements added in ___________ are ignored by JavaScript.
(B) Mistakes
(C) Java
(D) Python

Question 139.
___________ is used to perform repetitive tasks whenever required.
(A) Function
(B) parseInt()
(C) parseFloat()
(A) Function

Question 140.
___________ is reusable codeblock that will be executed when it is called.
(A) Function
(B) parseInt()
(C) parseFloat()
(A) Function

Question 141.
___________ function is used to parse a string and convert it into a number.
(A) Function
(B) parseInt()
(C) parseFloat()
(B) parseInt()

Question 142.
___________ function is used to parse a string and convert it into floating point representation.
(A) Function
(B) parseInt()
(C) parseFloat()
(C) parseFloat()

Question 143.
___________ function displays alert popup box with ok button. This is also called as a message box.
(A) Function
(B) parselnt()
(C) parseFloat()

Question 144.
___________ function is used when you want input value from user at the time of program execution.
(A) prompt()
(B) confirm()
(C) toLowerCase()
(D) toUpperCase()
(A) prompt()

Question 145.
___________ function displays confirmation message box with ok and cancel button.
(A) prompt()
(B) confirm()
(C) toLowerCase()
(D) toUpperCase()
(B) confirm()

Question 146.
___________ string function used to convert the given string into lower case alphabets.
(A) prompt()
(B) confirm()
(C) toLowerCase()
(D) toUpperCase()
(C) toLowerCase()

Question 147.
___________ string function is used to convert given string into uppercase alphabets.
(A) prompt()
(B) confirm()
(C) toLowerCase()
(D) toUpperCase()
(D) toUpperCase()

Question 148.
___________ returns ‘true’ if given value is not a number. It returns ‘false’ if given value is number.
(A) prompt()
(B) confirm()
(C) toLowerCase()
(D) isNaN()
(D) isNaN()

Question 149.
A ___________ in any scripting and programming language is a small part of a program that we require again and again.
(A) Function
(B) Gmail
(C) Hotmail
(D) Program
(A) Function

Question 150.
A ___________ is a subprogram designed to perform a particular task.
(A) Function
(B) Gmail
(C) Hotmail
(D) Program
(A) Function

Question 151.
___________ can be called either by an event or by giving call to that function.
(A) Function
(B) Gmail
(C) Hotmail
(D) Program
(A) Function

Question 152.
___________ is an event-driven language.
(A) JavaScript
(B) Event
(C) Function
(D) Driven
(A) JavaScript

Question 153.
___________ is an action done by the user or an application.
(A) JavaScript
(B) Event
(C) Function
(D) Driven
(B) Event

Question 154.
___________ lets you execute a code when events are detected.
(A) JavaScript
(B) Event
(C) Function
(D) Driven
(A) JavaScript

Question 155.
___________ when user moves the mouse away from an element.
(A) onMouseOut
(B) onClick
(C) onMouseOver
(D) onMouseUp
(A) onMouseOut

Question 156.
___________ when user clicks an element.
(A) onMouseOut
(B) onClick
(C) onMouseOver
(D) OnMouseUp
(B) onClick

Question 157.
___________ when user moves the mouse over an element.
(A) onMouseOut
(B) onClick
(C) onMouseOver
(D) OnMouseUp
(C) onMouseOver

Question 158.
___________ when user releases a mouse button over an element.
(A) onMouseOut
(B) onClick
(C) onMouseOver
(D) OnMouseUp
(D) onMouseUp

4. Multiple Choice Two Correct Answers.

Question 1.
The standards and formats for presenting __________ and __________ on the internet are developed and approved by world wide web governing authorities.
(A) web pages
(B) Text
(C) graphics
(D) websites
(E) text editor
(B) Text, (C) graphics

Question 2.
A web browser is a software used to view __________ or __________ available on the internet.
(A) web pages
(B) Text
(C) graphics
(D) websites
(E) text editor
(A) web pages, (D) websites

Question 3.
HyperText Transfer Protocol documents are created in any __________ for and can be run(executed) on any computer that has a __________
(A) web pages
(B) Text
(C) graphics
(D) text editor
(E) web browser
(D) text editor, (E) web browser

Question 4.
Every HTML page is enclosed within two tags __________ and __________
(B) body
(C) <html>
(D) Container tags
(E) </html>
(C) <html>, (E) </html>

Question 5.
The page is divided into two sections internally __________ section and __________ section.
(B) body
(C) <html>
(D) Container tags
(E) </html>

Question 6.
HTML tags are categorized as _________ & __________
(A) Beginning
(B) Container tags
(C) End
(D) Empty tags
(E) Standalone
(B) Container tags, (D) Empty tags

Question 7.
Container Tags have a __________ tag and an __________ tag.
(A) Beginning
(B) Container tags
(C) End
(D) Empty tags
(E) Standalone
(A) Beginning, (C) End

Question 8.
Empty tags are __________ tags and do not have an __________ tag.
(A) Beginning
(B) Container tags
(C) Standalone
(D) End
(E) Empty Tag
(C) Standalone, (D) End

Question 9.
_________ and __________ tag indicates that the document is an html file.
(B) body
(C) <html>
(D) Container tags
(E) </html>
(C) <html>, (E) </html>

Question 10.
____________ and __________ includes <Title> within it. the text within <head> is not displayed on the webpage.
(B) body
(D) Container tags

Question 11.
__________ and __________ content within this tag is displayed on the title bar.
(B) body
(C) <title>
(D) Container tags
(E) </title>
(C) <title>, (E) </title>

Question 12.
__________ and __________ tag includes all content which is to be developed in the web browser.
(B) body
(C) <body>
(D) Container tags
(E) </body>
(C) <body>, (E) </body>

Question 13.
<footer> defines a footer for a __________ or a __________
(A) Document
(B) Section
(C) Rows
(D) Columns
(E) Tags
(A) Document, (B) Section

Question 14.
A table is made up of __________ and __________
(A) Document
(B) Section
(C) Rows
(D) Columns
(E) Tags
(C) Rows, (D) Columns

Question 15.
The __________ and __________ used to create a table.
(A) Document
(B) Section
(C) Rows
(D) Tags
(E) Attributes
(D) Tags, (E) Attributes

Question 16.
A Hyperlink by default appears __________ in colour with an __________
(A) Get
(B) Blue
(C) Underline
(D) Post
(E) Text
(B) Blue, (C) Underline

Question 17.
The method attribute specifies __________ or __________ method to be used when submitting the form data.
(A) Get
(B) Blue
(C) Underline
(D) Post
(E) Text
(A) Get, (D) Post

Question 18.
Method of form are __________ or __________
(A) Get
(B) Blue
(C) Underline
(D) Post
(E) Text
(A) Get, (D) Post

Question 19.
Maxlength attribute is used with __________ and __________ type.
(A) Get
(B) Blue
(C) Underline
(D) Text

Question 20.
Maxlength specifies the maximum number of characters which can be entered in a __________ or __________ box.
(A) Get
(B) Blue
(C) Underline
(D) Text

Question 21.
The ‘Size’ attribute can be used with __________ and __________ type.
(A) Get
(B) Blue
(C) Underline
(D) Text

Question 22.
The ‘Checked’ attribute specifies the default selection for options in a __________ or __________ button.
(A) Checkbox
(B) Selected
(D) Value
(E) Client

Question 23.
The attributes of <option> tag are __________ & __________
(A) Checkbox
(B) Selected
(D) Value
(E) Client
(B) Selected, (D) Value

Question 24.
JavaScript can be use for __________ side or __________ side scripting language.
(A) Checkbox
(B) Selected
(D) Client
(E) Server
(D) Client, (E) Server

Question 25.
Number data type can hold __________ as well as __________ values.
(A) Positive
(B) Negative
(C) True
(D) False
(E) Logical
(A) Positive, (B) Negative

Question 26.
Boolean Type represents only two values ‘__________’ and ‘__________’.
(A) Positive
(B) Negative
(C) True
(D) False
(E) Logical
(C) True, (D) False

Question 27.
Operators are used to do __________ and __________ operations.
(A) Positive
(B) Negative
(C) True
(D) Arithmetic
(E) Logical
(D) Arithmetic, (E) Logical

Question 28.
Java script supports two types of comments __________ & __________
(A) Ok
(B) Single line comment
(C) Cancel
(D) Multiline Comment
(E) Programming
(B) Single line comment, (D) Multiline Comment

Question 29.
Confirm() function displays confirmation message box with __________ and __________ button.
(A) Ok
(B) Single line comment
(C) Cancel
(D) Multiline comment
(E) Programming
(A) Ok, (C) Cancel

Question 30.
A Function in any __________ and __________ languages is small part of program that we require again and again.
(A) Ok
(B) Single line comment
(C) Cancel
(D) Scripting
(E) Programming
(D) Scripting, (E) Programming

Question 31.
Functions can be called either by an __________ or by giving __________ to that function.
(A) Event
(B) User
(C) Application
(D) Call
(E) Attributes
(A) Event, (D) Call

Question 32.
Event is an action done by the __________ or an __________
(A) Event
(B) User
(C) Application
(D) Call
(E) Attributes
(B) User, (C) Application

5. Multiple Choice Three Correct Answers.

Question 1.
The popular extensions of image file are __________, __________ and __________
(A) Left
(B) Png
(C) Right
(D) Jpg
(E) Gif
(B) Png, (D) Jpg, (E) Gif

Question 2.
It aligns the table either to the __________, __________ or __________
(A) Left
(B) Png
(C) Right
(D) Center
(E) Gif
(A) Left, (C) Right, (D) Center

Question 3.
__________, __________, __________ tags can have bgcolor attribute for specifying background color to a row or a column respectively.
(A) <tr>
(B) <th>
(C) <td>
(D) Name
(E) Size
(A) <tr>, (B) <th>, (C) <td>

Question 4.
The attributes of <select> tag are __________, __________ & __________
(A) Name
(B) Alphabets
(C) Multiple
(D) Numbers
(E) Size
(A) Name, (C) Multiple, (E) Size

Question 5.
When we store information it is in the form of __________, __________ or __________ values.
(A) Name
(B) Alphabets
(C) Multiple
(D) Numbers
(E) Alphanumeric
(B) Alphabets, (D) Numbers, (E) Alphanumeric

Question 6.
In JavaScript null is, just a value which means “__________”, “__________”, “__________”
(A) Nothing
(B) Empty
(C) Unknown
(D) Arithmetic
(E) Relational
(A) Nothing, (B) Empty, (C) Unknown

Question 7.
Most of the operators can be divided into groups __________, __________ and __________ operators.
(A) Nothing
(B) Empty
(C) Arithmetic
(D) Relational
(E) Logical
(C) Arithmetic, (D) Relational, (E) Logical

6. Match the following.

Question 1.

 Column ‘A’ Column ‘B’ (1) World Wide Web (A) A collection of interlinked web page (2) Webpage (B) Web (3) Website (C) A simple text file created using HTML (4) Web Browser (D) A web browser is a software used to view web pages

 Column ‘A’ Column ‘B’ (1) World Wide Web (B) Web (2) Webpage (C) A simple text file created using HTML (3) Website (A) A collection of interlinked web page (4) Web Browser (D) A web browser is a software used to view web pages

Question 2.

 Column ‘A’ Column ‘B’ (1) Web Server (A) A protocol used by WWW (2) Uniform Resource Locator (B) An application or a computer that sends webpages (3) HyperText Transfer Protocol (C) An address of a web page on the internet (4) Hyper Text Markup Language (D) Enables to write code for a webpage

 Column ‘A’ Column ‘B’ (1) Web Server (B) An application or a computer that sends webpages (2) Uniform Resource Locator (C) An address of a web page on the internet (3) HyperText Transfer Protocol (A) A protocol used by WWW (4) Hyper Text Markup Language (D) Enables to write code for a webpage

Question 3.

 Column ‘A’ Column ‘B’ (1) Container Tags (A) Defines a header (2) Empty tags (B) Paired tags (3) (C) Standalone tags (4)
(D) A document type declaration

 Column ‘A’ Column ‘B’ (1) Container Tags (B) Paired tags (2) Empty tags (C) Standalone tags (3) (D) A document type declaration (4)

Question 4.

 Column ‘A’ Column ‘B’ (1)

 Column ‘A’ Column ‘B’ (1)

Question 5.

 Column ‘A’ Column ‘B’ (1)
(B) Displays text within it in italicized manner (3) (C) Displays text within it in Bold (4) (D) Defines a footer

 Column ‘A’ Column ‘B’ (1)
(D) Defines a footer (2)
(A) Defines additional details (3) (C) Displays text within it in Bold (4) (B) Displays text within it in italicized manner

Question 6.

 Column ‘A’ Column ‘B’ (1) (A) Displays text with underline (2) (B) Displays text in subscript form (3) (C) Displays text in small font size (4) (D) Anything that appears within element is displayed as inserted text

 Column ‘A’ Column ‘B’ (1) (A) Displays text with underline (2) (C) Displays text in small font size (3) (B) Displays text in subscript form (4) (D) Anything that appears within

Question 7.

 Column ‘A’ Column ‘B’ (1) (A) Smallest heading level (2) (B) Largest heading level (3)

(C) The HTML element defines marked or highlighted text (4)

(D) Anything that appears within … element, is displayed as deleted text

 Column ‘A’ Column ‘B’ (1) (D) Anything that appears within … element, is displayed as deleted text (2) (C) The HTML element defines marked or highlighted text (3)

Question 8.

 Column ‘A’ Column ‘B’ (1)  tag (A) Specifies the width of the image (2) src (B) It is used to specify the path of an image file (3) Height (C) Specifies the height of the image (4) Width (D) Insert an image

 Column ‘A’ Column ‘B’ (1)  tag (D) Insert an image (2) src (B) It is used to specify the path of an image file (3) Height (C) Specifies the height of the image (4) Width (A) Specifies the width of the image

Question 9.

 Column ‘A’ Column ‘B’ (1) alt (A) It is referred to as alternate text (2)
tag (B) Define paragraphs (3)

tag (C) Display horizontal ruled line (4) table (D) Rows and column

 Column ‘A’ Column ‘B’ (1) alt (A) It is referred as alternate text (2)
tag (C) Display horizontal ruled line (3)

tag (B) Define paragraphs (4) table (D) Rows and column

Question 10.

 Column ‘A’ Column ‘B’ (1) (A) It indicates table heading (2) (B) It is used to speedy a table heading (3)
(D) It is used to indicate creation of a table
(C) Create each row of the table (4)

 Column ‘A’ Column ‘B’ (1) (D) It is used to indicate creation of a table (2) (B) It is used to speedy a table heading (3)
(C) Create each row of the table (4)

Question 11.

 Column ‘A’ Column ‘B’ (1)
(A) It specifies data within the table (2) Border (B) Aligns the table (3) Border color (C) Displays border in a specific color (4) Align (D) Display a border

 Column ‘A’ Column ‘B’ (1)
(A) It specifies data within the table (2) Border (D) Display a border (3) Border color (C) Displays border in a specific color (4) Align (B) Aligns the table

Question 12.

 Column ‘A’ Column ‘B’ (1) Bgcolor (A) Creates a checkbox (2) (B) Creates a one line textbox (3) (C) Creates a radio button (4) (D) Sets the background color

 Column ‘A’ Column ‘B’ (1) Bgcolor (D) Sets the background color (2) (B) Creates a one line textbox (3) (C) Creates a radio button (4) (A) Creates a checkbox

Question 13.

 Column ‘A’ Column ‘B’ (1) (A) Displays a button for submitting (2) (B) The reset control clears the text content (3) (C) Create text contents in the form of ‘*’asterik or ‘ . ‘ disc (4) (D) Displays push button

 Column ‘A’ Column ‘B’ (1) (A) Displays a button for submitting (2) (C) Create text contents in the form of ‘*’asterik or ‘ . ‘ disc (3) (B) The reset control clears the text content (4) (D) Displays push button

Question 14.

 Column ‘A’ Column ‘B’ (1) Number type (A) Division by 0 (2) String Type (B) Storing text (3) Boolean Type (C) ‘True’ and ‘False’ (4) Infinity (D) ‘Number’ data type

 Column ‘A’ Column ‘B’ (1) Number type (D) ‘Number’ data type (2) String Type (B) Storing text (3) Boolean Type (C) ‘True’ and ‘False’ (4) Infinity (A) Division by 0

Question 15.

 Column ‘A’ Column ‘B’ (1) Null (A) “Nothing”, “Empty”, “Unknown” (2) Undefined (B) Arithmetic and logical operations (3) Operators (C) Variable which is declared but not assigned (4) One operand (D) Unary operator

 Column ‘A’ Column ‘B’ (1) Null (A) “Nothing”, “Empty”, “Unknown” (2) Undefined (C) Variable which is declared but not assigned (3) Operators (B) Arithmetic and logical operations (4) One operand (D) Unary operator

Question 16.

 Column ‘A’ Column ‘B’ (1) Two operands (A) Mathematical expressions (2) Arithmetic operators (B) Binary operator (3) Relational operators (C) Check conditions or comparison of operands (4) Comments (D) Non-executable statements

 Column ‘A’ Column ‘B’ (1) Two operands (B) Binary operator (2) Arithmetic operators (A) Mathematical expressions (3) Relational operators (C) Check conditions or comparison of operands (4) Comments (D) Non-executable statements

Question 17.

 Column ‘A’ Column ‘B’ (1) ParseInt() (A) Number (2) ParseFloat() (B) Floating point (3) Alert() (C) Displays ok and cancel buttons (4) Prompt() (D) Message box

 Column ‘A’ Column ‘B’ (1) ParseInt() (A) Number (2) ParseFloat() (B) Floating point (3) Alert() (D) Message box (4) Prompt() (C) Displays ok and cancel buttons

Question 18.

 Column ‘A’ Column ‘B’ (1) Confirm() (A) Function displays a confirmation message box (2) toLowerCase() (B) Convert the given string into lower case alphabets (3) toUpperCase() (C) Convert given string into uppercase alphabets (4) onMouseOut (D) When the user moves the mouse away from an element

 Column ‘A’ Column ‘B’ (1) Confirm() (A) Function displays a confirmation message box (2) toLowerCase() (B) Convert the given string into lower case alphabets (3) toUpperCase() (C) Convert given string into uppercase alphabets (4) onMouseOut (D) When the user moves the mouse away from an element

Question 19.

 Column ‘A’ Column ‘B’ (1) onClick (A) When the user presses a key (2) onMouseOver (B) When the user moves the mouse over an element (3) onMouseUp (C) When the user releases a mouse button over an element (4) onKeyDown (D) When a user clicks an element (5) onKeyUp (E) When the user releases key

 Column ‘A’ Column ‘B’ (1) onClick (D) When a user clicks an element (2) onMouseOver (B) When the user moves the mouse over an element (3) onMouseUp (C) When the user releases a mouse button over an element (4) onKeyDown (A) When the user presses a key (5) onKeyUp (E) When the user releases key

Question 1.
What is Internet?

1. Online resources have become a part of our day-to-day life.
2. The Internet is a powerful medium to transmit information.
3. The pages of the information displayed on the internet are referred to as Webpages.
4. The standards and formats for presenting text and graphics on the internet are developed and approved by worldwide web governing authorities.
5. The growing demand for attractive presentation of information using electronic means gave rise to the invention of Websites.

Question 2.
Discuss the Components of the web.

1. WWW stands for world wide web.
2. WWW stands for world wide web normally referred to as Web.
3. The webpage is a simple text file created using HTML.
4. A website is a collection of interlinked web pages containing text, images, audio, and videos.
5. A web browser is software used to view web pages or websites available on the internet.
6. A Web server is an application or a computer that sends webpages over the internet using the HTTP protocol.
7. The functionality of the website is managed by the webserver.
8. The full form of URL is Uniform Resource Locator.
9. Uniform Resource Locator is an address of a web page on the internet.
10. The web pages are retrieved from the original location with the help of a Uniform Resource Locator.
11. The full form of HTTP is HyperText Transfer Protocol.
12. HyperText Transfer Protocol is a protocol used by WWW for client-server communication.
13. The full form of HTML is HyperText Markup Language.
14. HyperText Markup Language enables to write code for a webpage.
15. All the web pages in a website are linked with one another, with the help of Hypertext Links.

Question 3.
What is HTML?

1. HyperText Markup Language is a standard language for developing and creating interactive websites, introduced by Tim Berners Lee.
2. HyperText Markup Language documents are created in any text editor and can be run(executed) on any computer that has a web browser.
3. HyperText Markup Language is compatible with most web browsers.

Question 4.
Write down the classification of HTML Tags.
HTML tags are categorized as Container tags & Empty tags

1. Container Tags are also called paired tags.
2. Container Tags have a beginning tag and an end tag.
3. Empty Tags are standalone tags and do not have an end tag.

Question 5.
Discuss the structure of a web page using HTML5.

3. <seetion> defines a section in a document.
4. <article> defines an independent self-contained article.
5. <aside> defines content apart from the content (like a sidebar).
6. <footer> defines a footer for a document or a section.

Question 6.
Explain the Text formatting element.

1. Text formatting is used to make a document look attractive thereby enhancing its appearance.
2. <b> displays text within it in Bold like Hello.
3. <i> displays text within it in an italicized manner like Hello.
4. <u> displays text with an underline like Hello.
5. <small> displays text in small font size.
6. <sub> displays text in subscript form.
7. <sup> displays text in superscript form.
8. The HTML <mark> element defines marked or highlighted text.

Question 7.

1. HTML provides six levels of heading tags.
2. The <H1> tag displays text in bold and with the largest heading level.
3. The <H6> tag displays text in the smallest heading level.

Question 8.
Explain Inserting an image, a horizontal ruled line, and a paragraph.

1. <IMG> tag is used to insert an image within a webpage.
2. src is used to specify the path of an image file.
3. Height specifies the height of the image in pixels.
4. Width specifies the width of the image in pixels.
5. Alt is referred to as alternate text.
6. <IMG> is an empty tag.
7. <hr> tag is used to display horizontal ruled line.
8. color sets the color for the horizontal ruled line.
9. Width specifies the length of the ruled line in % or pixels.
10. Size sets the thickness of a ruled line.
11. <P> tag is used to define paragraphs.

Question 9.
Write a note on creating a table.

1. A Table is made up of rows and columns.
2. <table> is used to indicate the creation of a table.
3. <caption> is used to specify a table heading.
4. <tr> tag is used to create each row of the table.
6. <td> specifies data within the table (cell content).

Question 10.
Discuss the attributes of the table.

1. A border attribute is required to display a border for the entire table.
2. Border color displays borders in a specific color.
3. Aligns the table either to the left, right, or center.
4. Bgcolor sets the background color for the table.

Question 11.

1. Hyperlinks are used to connect one document with another document.
2. In HTML, Links are created by using <a> tag.
3. A Hyperlink by default appears blue in colour with an underline.
4. A Visited link is underlined and purple.
5. An Active link is underlined and blue.

Question 12.
Discuss the Forms in HTML.

1. Forms in HTML are used to accept user input.
2. A Form is a collection of different elements also called controls.
3. Name attributes specifies a name to a form.
4. The Action attribute specifies the path where the form is to be submitted.
5. The Method attribute specifies the get or post method to be used when submitting the form data.
6. The default method of submitting form data is GET.
7. The data submitted by using GET is visible in the address bar.
8. The POST method of sending data does not display the form data in the address bar.

Question 13.
Explain the <Input> tag and type of control.

1. <Input type = “text”> creates a one-line Textbox.
3. The Radio button allows one option selection against multiple choices.
4. <Input type = “checkbox’^ creates a Checkbox.
5. A checkbox allows more than one selection against multiple choices.
6. <Input type = “submit”> displays a button for Submitting the form data to a server.
7. The Password input type is used to create text contents in the form of ‘*’ asterisk or ‘•’ disc.
8. The Reset control clears the text content entered in the form.
9. <Input type = “Button.”> displays push button which activates on events.

Question 14.
Write down the attributes of <Input>.

1. The type describes the name of the control like text radio.
2. The Name attribute is a user-defined value.
3. Maxlength attribute is used with text and password type.
4. Max length specifies the maximum number of characters that can be entered in a text or password box.
5. The ‘Size’ attribute can be used with text and password type.
6. Size specifies the width of the text box.
7. The ‘Checked’ attribute specifies the default selection for options in a checkbox or radio button.
8. The ‘Value’ attribute can be used with text, checkbox, radio, submit or reset.

Question 15.
Explain <Textarea> tag and its attribute.

1. The <Textarea> tag is used to create a textbox with multiple lines.
2. Name is used to specify a name for the textarea.
3. Rows specify the number of lines in a text area.
4. Cols specify the width of a text area.
5. Max length specifies the maximum number of characters allowed in the textarea.
6. Placeholder specifies a short hint that describes the expected value of a textarea.
7. Required specifies that textarea must be filled out. i.e. It can not be blank.

Question 16.
Explain the attributes of <select> and <option> tag.

1. <select> tag is used to create drop-down list.
2. Name assigns a name to the control.
3. Multiple allows the user to select more than one value.
4. The Size attribute is used to specify the number of visible values.
5. To define the preselected option, the ‘Selected‘ attribute is added to the <option>.
6. Value assigns value to the option specified in the dropdown list.

Question 17.
Write down Scripting in HTML.

1. JavaScript was initially created to make web pages alive.
2. A Script is a list of commands that are executed by a scripting engine.
3. Scripts are used to generate dynamic Web pages on the Web.
4. JavaScript can be used for the client-side or server-side scripting language.
5. JavaScript code can be inserted in HTML program between <script> and </script> tag.
6. The language attribute is used to set scripting language.

Question 18.
Explain Variables.

1. A Variable is a basic unit of storage in a JavaScript program.
2. The variable name may consist of alphabets, digits and underscore, and dollar characters with the following rules.
3. Standard keywords are not allowed as Variable names.
4. Variable names can be limited to up to 255 characters.
5. Variable name in javascript is declared with keyword ‘var’.

Question 19.
Explain Data Types.

1. JavaScript provides data types to store and use different types of values.
2. Numerical value specially belongs to the ‘Number’ data type.
3. Number data types can hold positive as well as negative values.
4. Strings are used for storing text.
5. Boolean type represents only two values ‘true’ and ‘false’.
6. JavaScript returns ‘Undefined’ when a variable is declared but not assigned.

Question 20.
Discuss Operators and types of Operators.

1. Operators are used to doing arithmetic and logical operations.
2. Operators that require one operand is called as Unary operator.
3. Operators that require two operands are called Binary operators.
4. Arithmetic operators are used in mathematical expressions.
5. It is important to know that the Assignment operator is not ‘equal to’ operator.
6. The assignment operator is used to assign the value of an expression to a variable.
7. Relational operators are used to checking conditions or comparisons of operands.
8. Logical operators are used to verifying more than one condition at a time or to negate the condition.
9. The increment (++) operator in JavaScript is used to increment the value of the variable by one.
10. Decrement operator in JavaScript is used to decrement the value of the variable by one.

Question 21.

1. Comments are non-executable statements in the program.

Question 22.
What is Function and commonly used Built-In Functions in JavaScript?

1. The function is used to perform repetitive tasks whenever required.
2. The function is a reusable code block that will be executed when it is called.
3. parselnt() function is used to parse a string and convert it into a number
4. parseFloat() function is used to parse a string and convert it into floating-point representation.
5. alert() function displays an alert popup box with an ok button. This is also called a message box
6. prompt() function is used when you want input value from the user at the time of program execution.
7. confirm() function displays a confirmation message box with ok and cancels button
8. toLowerCase() string function used to convert the given string into lower case alphabets
9. toUpperCase() string function is used to convert given string into uppercase alphabets
10. isNaN() returns ‘true’ if given value is not a number. It returns ‘false’ if the given value is a number.

Question 23.
What are User Defined Functions?

1. A Function in any scripting and programming language is small part of a program that we require again and again.
2. A Function is a subprogram designed to perform a particular task.
3. Functions can be called either by an event or by giving a call to that function.

Question 24.
Explain Event Handling.

1. JavaScript is an event-driven language.
2. An event is an action done by the user or an application.
3. JavaScript lets you execute a code when events are detected.

Question 25.
Explain Event Handler.

1. onMouseOut when the user moves the mouse away from an element.
2. onClick when the user clicks an element.
3. onMouseOver when the user moves the mouse over an element.
4. onMouseUp when the user releases a mouse button over an element.

8A. Write Codes in HTML.

Question 1.
My First Page in HTML
<html>
<title> First Page </title>
<body bgcolor = green >
<font color=”red” size=”20″> This is my first web page
</body>
</html>

Question 2.
Write the the HTML Program which contains Text Formatting Elements.
<!DOCTYPE html>
<html>
<title>Example of HTML5 text formatting tags</title>
<body>
<b>This text is bold</b><br><br>
<i>This text is italic</i><br><br>
<mark>This text is marked</ mark><br><br>
This is <sub>subscript</sub> and <sup>superscript</sup><br><br>
<ins>This text is inserted to the document</ins><br><br>
<del>This text is deleted from the document</del><br><br>
</body>
</html>

Question 3.
Write down the HTML program which provides six levels of the heading tags.
<!DOCTYPE html>
<html>
<body bgcolor=skyblue>
<H1>Heading level 1 Text is largest in size</H1>
<H6>Heading level 6 Text is smallest in size</H6>
</body>
</html>

Question 4.
Create a table in HTML which contains 4 rows and 3 columns.
<!DOCTYPE html>
<html>
<title>Table with 4 rows and 3 columns</title>
<body>
<table border=”2″>
<tr>
<th>Sr. No.</th>
<th>Input Device</th>
<th>Output Device</th>
</tr>
<tr>
<td>1</td>
<td>Keyboard</td>
<td>Monitor</td>
</tr>
<tr>
<td>2</td>
<td>Mouse</td>
<td>Printer</td>
</tr>
<tr>
<td>3</td>
<td> Joystick</td>
<td>Plotter</td>
</tr>
</table>
</body></html>

Question 5.
Create a table in HTML with rowspan attribute.
<!DOCTYPE html>
<html>
<title>Table with rowspan attribute</title>
<table border=”3″>
<tr>
<td rowspan=2>Colors</td>
<td bgcolor=red>Red</td>
</tr>
<tr>
<td bgcolor=green>Green</td>
</tr>
</table>
</body>
</html>

Question 6.
Create a table in HTML with col span attribute.
<!DOCTYPE html>
<html>
<title> Table with colspan</title>
<body>
<table border =”3″>
<tr>
<td colspan=”2″ align=”center”> Colors </td>
</tr>
<tr>
<td bgcolor=red>Red</td>
<td bgcolor=green>Green</td>
</tr>
</table>
</body>
</html>

Question 7.
Create a Form with input elements in HTML.
<!DOCTYPE html>
<html>
<title>Form with Input elements</title>
<body bgcolor=”orange”>
<h1>use of form</h1>
<form>
<input type=”text” Name-‘n1″ max length=”20″><Br>
11<sup>th</sup>
12<sup>th</sup><br>
Choose your optional subjects : <br>
<input type=”checkbox” name=”c1″ Value=”Hindi”>Hindi<br>
<input type=”checkbox” name=”c1″ Value=”German”>German<br>
<input type=”checkbox” name=”c1″ Value=”Biology”>Biology<br>
<input type=”checkbox” name=”c1″ Value=”IT”>IT<br>
<input type=”submit” value=”Submit”><br>
</form>
</body>
</html>

Question 8.
Create a Form element and textarea in HTML.
<!DOCTYPE html>
<html>
<title> Form elements and textarea</title>
<body bgcolor = “cyan” text=”Red”>
<h1> Use of form elements </h1>
<form method = “post” action = “data.php”>
<input type = “text” name = “fn”> <br>
<select name=”ct”>
<option>Pune</option>
<option>Nagpur</option>
<option>Solapur</option>
</select><br>
</textarea> <br>
<input type = “submit” value = “send”>
</form>
</body>
</html>

Question 9.
Write down the HTML 5 program it includes semantic tags like header, footer & nav.
<!Doctype Html>
<html>
<title> Html 5 program it includes semantic tags like header, footer & nav </title>
<body bgcolor=yellow>
<h1>HTML5 includes new semantics</h1>
<h1>Example of complete HTML5 Basics</h1>
<h2>The markup of the future under development.</h2>
<nav>
</nav>
<aside>
<h1>Other education based websites of State</h1>
<a href=”http://mahahsscboard.ac.in”>State Board website</a><br>
<a href=”http://examinfo.mhhsc.ac.in”>Online Exam Website<a/><br>
</aside>
<section>
<h1>Impressive Web Designing</h1>
<p>The aside element is for content that is tangentially related to the content around it, and is typically useful for marking up sidebars.</p></section><section> <h1>Articles on:Article tag</h1>
</section>
<article>
<p>The article element represents an independent section of a document, page or site. It is suitable for content like news or blog articles, forum posts or individual comments.</p>
</article>
</body>
</html>

8B. Write a program in Javascript.

Question 1.
Write a JavaScript program to calculate the multiplication of two numbers.
<!DOCTYPE html>
<html>
<title>multiplication of two numbers</title>
<body bgcolor=”yellow”>
<h1>Program to calculate multiplication of two numbers </h1>
<script language=”javascript”>
var a,b,c;
a=75; b=100.45;
c=a*b;
document.write(“<br><h1>multiplication of two numbers : “+c+”</h1>”);
</script>
</body>
</html>

Question 2.
Write a program to calculate the area of a circle.
<!DOCTYPE html>
<html>
<title>Area of circle</title>
<body bgcolor=yellow>
<h1> Program to calculate area of circle </h1>
<script language=”javascript”>
var r,area;
area=3.14*r*r;
document.write(“<h1>you entered radius value: </h1>” +r);
document.write(“<h1>Area of circle is: </h1>”+area);
</script>
</body>
</html>

Question 3.
Write a Program to check number is even or odd.
<!DOCTYPE html>
<html>
<title>Program to check number is even or odd</title>
<body bgcolor=”green”>
<h1> Program to check number is even or odd </h1>
<script language=”javascript”> var a,b
b=parseInt(a);
// input is converted into number data type
if(b%2==0)
</script>
</body>
</html>

Question 4.
Write a Java Script Program which contains Conditional Statement.
<!DOCTYPE html>
<html>
<title>conditional statement</title>
<script language=”javascript”>
function check()
{
var age;
age=form1.t1.value;
if(age>=18)
else
}
</script>
<body>
<form name=”form 1″>
<input type=”button” value=”SUBMIT” onClick=”check()”>
</form>
</body>
</html>

## Maharashtra Board Class 11 Information Technology Important Questions Chapter 2 Introduction to DBMS

Balbharati Maharashtra State Board Class 11 Information Technology Important Questions Chapter 2 Introduction to DBMS Important Questions and Answers.

## Maharashtra State Board 11th Information Technology Important Questions Chapter 2 Introduction to DBMS

1. Fill in the Blanks.

Question 1.
A ___________ often abbreviated as DB.
Database

Question 2.
___________ is collection of interrelated data.
Database

Question 3.
Full for of DBMS is ___________
Database Management System

Question 4.
A ___________ is a software for creating and managing databases.
Database Management System

Question 5.
The ___________ provides users and programmers with a systematic way to create, retrieve, update and manage data.
Database Management System

Question 6.
___________ holds a fixed-length string (can contain letters, numbers, and special characters).
CHAR

Question 7.
___________ holds a variable length string (can contain letters, numbers, and special characters).
VARCHAR

Question 8.
___________ can represent numbers with or without the fractional part.
DECIMAL

Question 9.
___________ is used for storing integer values.
INT

Question 10.
___________ holds the date including day, month and year.
DATE

Question 11.
___________ holds time. Format: HH:MM:SS.
TIME()

Question 12.
This logical structure of database is known as a ___________
Model

Question 13.
___________ define how the data is connected to each other and how they are processed and stored inside the system.
Data model

Question 14.
___________ describes the method of storing and retrieving the data.
Data model

Question 15.
___________ is the primary data model, which is used widely around the world for data storage and processing.
Relational data model

Question 16.
___________ is simple and has all the properties and capabilities required to process data with storage efficiency.
Relational data model

Question 17.
___________ ensures that all operations within the work unit are completed successfully.
Atomicity

Question 18.
___________ ensures that the database properly changes states upon a successfully committed transaction.
Consistency

Question 19.
___________ enables transactions to operate independently of and transparent to each other.
Isolation

Question 20.
___________ ensures that the result or effect of a committed transaction persists in case of a system failure.
Durability

Question 21.
RDBMS stands for ___________
Relational Database Management System

Question 22.
In ___________ a database is considered as a collection of interrelated data.
Relational Database Management System

Question 23.
The ___________ is the basic data storage unit in a Relational database.
Table

Question 24.
___________ consists of columns and rows.
Table

Question 25.
A ___________ consists of one or more tables according to which data is stored in a table.
Database

Question 26.
___________ designer decides the name of the table and titles of columns.
Database

Question 27.
A ___________ is composed of fields and contains all the data about one particular person, company, or item in a database.
Record

Question 28.
Record is also called as a ___________
Tuple

Question 29.
A column or a combination of columns that can be used to identify one or more rows (tuples) in a table is called a ___________ of the table.
Key

Question 30.
The group of one or more columns used to uniquely identify each row of a relation is called its ___________
Primary Key

Question 31.
___________ is a field (or collection of fields) in one table that refers to the Primary Key in another table.
Foreign Key

Question 32.
___________ link data from individual tables to increase the usefulness of the database.
Relationships

Question 33.
A ___________ in the context of databases, is a situation that exists between two relational database tables.
Relationship

Question 34.
In a ___________ relationship, one record in a table is associated with one and only one record in another table.
One-to-One

Question 35.
___________ relationships can also be viewed as Many-to-One relationships, depending on which way you look at it.
One-to-Many

Question 36.
A ___________ relationship occurs when multiple records in a table are associated with multiple records in another table.
Many-to-Many

Question 37.
Full form of SQL is ___________
Structured Query Language

Question 38.
___________ is the standard language for Relational Database Management System.
Structured Query Language

Question 39.
Full form of DDL is ___________
Data Definition Language

Question 40.
___________ statements or commands are used to define and modify the database structure of your tables or schema.
Data Definition Language

Question 41.
Full form of DML is ___________
Data Manipulation Language

Question 42.
___________ statements or commands are used for managing data within tables.
Data Manipulation Language

Question 43.
Full form of DCL is ___________
Data Control Language

Question 44.
___________ is used to control user access in a database.
Data Control Language

2. True or False.

Question 1.
A database is often abbreviated as DB.
True

Question 2.
Hardware is a collection of interrelated data.
False

Question 3.
The full form of DBMS is Database Management System.
True

Question 4.
A Database Management System is software for creating and managing databases.
True

Question 5.
Information Technology provides users and programmers with a systematic way to create, retrieve, update and manage data.
False

Question 6.
DECIMAL holds a fixed-length string (can contain letters, numbers, and special characters).
False

Question 7.
VARCHAR holds a variable-length string (can contain letters, numbers, and special characters).
True

Question 8.
CHAR can represent numbers with or without the fractional part.
False

Question 9.
INT is used for storing integer values.
True

Question 10.
TIME() holds the date including day, month, and year.
False

Question 11.
DATE holds time. Format: HH:MM:SS.
False

Question 12.
This logical structure of the database is known as a computer.
False

Question 13.
Information Technology defines how the data is connected to each other and how they are processed and stored inside the system.
False

Question 14.
The data model describes the method of storing and retrieving the data.
True

Question 15.
The relational data model is the primary data model, which is used widely around the world for data storage and processing.
True

Question 16.
The relational data model is simple and has all the properties and capabilities required to process data with storage efficiency.
True

Question 17.
Consistency ensures that all operations within the work unit are completed successfully.
False

Question 18.
Atomicity ensures that the database properly changes states upon a successfully committed transaction.
False

Question 19.
Isolation enables transactions to operate independently of and be transparent to each other.
True

Question 20.
Durability ensures that the result or effect of a committed transaction persists in case of a system failure.
True

Question 21.
RDBMS stands for Relational Database Management System.
True

Question 22.
In Relational Database Management System a database is considered as a collection of interrelated data.
True

Question 23.
The Table is the basic data storage unit in a Relational database.
True

Question 24.
The table consists of columns and rows.
True

Question 25.
A record consists of one or more tables according to which data is stored in a table.
False

Question 26.
The record designer decides the name of the table and the titles of columns.
False

Question 27.
A Tuple is composed of fields and contains all the data about one particular person, company, or item in a database.
False

Question 28.
Record is also called a Tuple.
True

Question 29.
A column or a combination of columns that can be used to identify one or more rows (tuples) in a table is called a Key of the table.
True

Question 30.
The group of one or more columns used to uniquely identify each row of a relation is called its Primary Key.
True

Question 31.
Foreign Key is a field (or collection of fields) in one table that refers to the Primary Key in another table.
True

Question 32.
Relationships link data from individual tables to increase the usefulness of the database.
True

Question 33.
A Relationship in the context of databases is a situation that exists between two relational database tables.
True

Question 34.
In a Many-to-Many relationship, one record in a table is associated with one and only one record in another table.
False

Question 35.
One-to-Many relationships can also be viewed as Many-to-One relationships, depending on which way you look at them.
True

Question 36.
A One-to-One relationship occurs when multiple records in a table are associated with multiple records in another table.
False

Question 37.
The full form of SQL is Structured Query Language.
True

Question 38.
Data Definition Language is the standard language for Relational Database Management System.
False

Question 39.
The full form of DDL is Data Definition Language.
True

Question 40.
Structured Query Language statements or commands are used to define and modify the database structure of your tables or schema.
False

Question 41.
The full form of DML is Data Manipulation Language.
True

Question 42.
Data Definition Language statements or commands are used for managing data within tables.
False

Question 43.
The full form of DCL is Data Control Language.
True

Question 44.
Data Manipulation Language is used to control user access in a database.
False

3. Multiple Choice Question (Single Choice)

Question 1.
A ___________ often abbreviated as DB.
(A) Database
(B) Direct Banking
(C) Data Bank
(D) Direct Bank
(A) Database

Question 2.
___________ is a collection of interrelated data.
(A) Database
(B) Direct Banking
(C) Data Bank
(D) Direct Bank
(A) Database

Question 3.
Full form of DBMS is ___________
(A) Database Machine System
(B) Direct Banking Management System
(C) Data Bank Management
(D) Database Management System
(D) Database Management System

Question 4.
A ___________ is a software for creating and managing databases.
(A) Database
(B) Direct Banking
(C) Data Bank
(D) Database Management System
(D) Database Management System

Question 5.
The ___________ provides users and programmers with a systematic way to create, retrieve, update and manage data.
(A) Database
(B) Direct Banking
(C) Data Bank
(D) Database Management System
(D) Database Management System

Question 6.
___________ holds a fixed-length string (can contain letters, numbers, and special characters).
(A) CHAR
(B) VARCHAR
(C) DECIMAL
(D) INT
(A) CHAR

Question 7.
___________ holds a variable-length string (can contain letters, numbers, and special characters).
(A) CHAR
(B) VARCHAR
(C) DECIMAL
(D) INT
(B) VARCHAR

Question 8.
___________ can represent numbers with or without the fractional part.
(A) CHAR
(B) VARCHAR
(C) DECIMAL
(D) INT
(C) DECIMAL

Question 9.
___________ is used for storing integer values.
(A) CHAR
(B) VARCHAR
(C) DECIMAL
(D) INT
(D) INT

Question 10.
___________ holds the date including day, month and year.
(A) DATE
(B) TIME()
(C) CHAR
(D) VARCHAR
(A) DATE

Question 11.
___________ holds time. Format: HH:MM:SS.
(A) DATE
(B) TIME()
(C) CHAR
(D) VARCHA
(B) TIME()

Question 12.
This logical structure of database is known as a ___________
(A) Model
(B) Data model
(C) Storage and Processing
(D) Relational data model
(A) Model

Question 13.
___________ define how the data is connected to each other and how they are processed and stored inside the system.
(A) Model
(B) Data model
(C) Storage and Processing
(D) Relational data model
(B) Data model

Question 14.
___________ describes the method of storing and retrieving the data.
(A) Model
(B) Data model
(C) Storage and Processing
(D) Relational data model
(B) Data model

Question 15.
___________ is the primary data model, which is used widely around the world for data storage and processing.
(A) Model
(B) Data model
(C) Storage and Processing
(D) Relational data model
(D) Relational data model

Question 16.
___________ is simple and has all the properties and capabilities required to process data with storage efficiency.
(A) Model
(B) Data model
(C) Storage and Processing
(D) Relational data model
(D) Relational data model

Question 17.
___________ ensures that all operations within the work unit are completed successfully.
(A) Atomicity
(B) Consistency
(C) Isolation
(D) Durability
(A) Atomicity

Question 18.
___________ ensures that the database properly changes states upon a successfully committed transaction.
(A) Atomicity
(B) Consistency
(C) Isolation
(D) Durability
(B) Consistency

Question 19.
___________ enables transactions to operate independently of and transparent to each other.
(A) Atomicity
(B) Consistency
(C) Isolation
(D) Durability
(C) Isolation

Question 20.
___________ ensures that the result or effect of a committed transaction persists in case of a system failure.
(A) Atomicity
(B) Consistency
(C) Isolation
(D) Durability
(D) Durability

Question 21.
RDBMS stands for ___________
(A) Relational Database Management System
(B) Regional Database Management System
(C) Recovery Database Management System
(D) Recovery Database Microsoft System
(A) Relational Database Management System

Question 22.
In ___________ a database is considered as a collection of interrelated data.
(A) Relational Database Management System
(B) Regional Database Management System
(C) Recovery Database Management System
(D) Recovery Database Microsoft System
(A) Relational Database Management System

Question 23.
The ___________ is the basic data storage unit in a Relational database.
(A) Table
(B) Database
(C) Record
(D) Tuple
(A) Table

Question 24.
___________ consists of columns and rows.
(A) Table
(B) Database
(C) Record
(D) Tuple
(A) Table

Question 25.
A ___________ consists of one or more tables according to which data is stored in a table.
(A) Table
(B) Database
(C) Record
(D) Tuple
(B) Database

Question 26.
___________ designer decides the name of the table and titles of columns.
(A) Table
(B) Database
(C) Record
(D) Tuple
(B) Database

Question 27.
A ___________ is composed of fields and contains all the data about one particular person, company, or item in a database
(A) Table
(B) Database
(C) Record
(D) Tuple
(C) Record

Question 28.
Record is also called as a ___________
(A) Table
(B) Database
(C) Record
(D) Tuple
(D) Tuple

Question 29.
A column or a combination of columns that can be used to identify one or more rows (tuples) in a table is called a ___________ of the table.
(A) Key
(B) Primary Key
(C) Foreign Key
(D) Table
(A) Key

Question 30.
The group of one or more columns used to uniquely identify each row of a relation is called its ___________
(A) Key
(B) Primary Key
(C) Foreign Key
(D) Table
(B) Primary Key

Question 31.
___________ is a field (or collection of fields) in one table that refers to the Primary Key in another table.
(A) Key
(B) Primary Key
(C) Foreign Key
(D) Table
(C) Foreign Key

Question 32.
___________ link data from individual tables to increase the usefulness of the database.
(A) Relationships
(B) Primary Key
(C) Foreign Key
(D) Table
(A) Relationships

Question 33.
A ___________ in the context of databases, is a situation that exists between two relational database tables.
(A) Relationship
(B) Primary Key
(C) Foreign Key
(D) Table
(A) Relationship

Question 34.
In a ___________ relationship, one record in a table is associated with one and only one record in another table.
(A) One-to-One
(B) One-to-Many
(C) Many-to-Many
(D) Database
(A) One-to-One

Question 35.
___________ relationships can also be viewed as Many-to-One relationships, depending on which way you look at it.
(A) One-to-One
(B) One-to-Many
(C) Many-to-Many
(D) Database
(B) One-to-Many

Question 36.
A ___________ relationship occurs when multiple records in a table are associated with multiple records in another table.
(A) One-to-One
(B) One-to-Many
(C) Many-to-Many
(D) Database
(C) Many-to-Many

Question 37.
Full form of SQL is ___________
(A) Structured Query Language
(B) Structured Question Language
(C) Sequence Question Language
(D) Simple Query Language
(A) Structured Query Language

Question 38.
___________ is the standard language for Relational Database Management System.
(A) Structured Query Language
(B) Structured Question Language
(C) Sequence Question Language
(D) Simple Query Language
(A) Structured Query Language

Question 39.
Full form of DDL is ___________
(A) Data Definition Language
(B) Database Device Language
(C) Device Definition Language
(D) Data Division Language
(A) Data Definition Language

Question 40.
___________ statements or commands are used to define and modify the database structure of your tables or schema.
(A) Data Definition Language
(B) Database Device Language
(C) Device Definition Language
(D) Data Division Language
(A) Data Definition Language

Question 41.
Full form of DML is ___________
(A) Data Manipulation Language
(B) Data Machine Language
(C) Data Management Language
(D) Device Manipulation Language
(A) Data Manipulation Language

Question 42.
___________ statements or commands are used for managing data within tables.
(A) Data Manipulation Language
(B) Data Machine Language
(C) Data Management Language
(D) Device Manipulation Language
(A) Data Manipulation Language

Question 43.
Full form of DCL is ___________
(A) Dynamic Control Language
(B) Data Control Language
(C) Data Control List
(D) Dynamic Control List
(B) Data Control Language

Question 44.
___________ is used to control user access in a database.
(A) Dynamic Control Language
(B) Data Control Language
(C) Data Control List
(D) Dynamic Control List
(B) Data Control Language

4. Multiple Choice Two Correct Answers.

Question 1.
A Database Management System is a software for ___________ and ___________ databases.
(A) Creating
(B) Storing
(C) Retrieving
(D) Managing
(E) Processing
(A) Creating, (D) Managing

Question 2.
Data model describes the method of ___________ and ___________ the data.
(A) Creating
(B) Storing
(C) Retrieving
(D) Managing
(E) Processing
(B) Storing, (C) Retrieving

Question 3.
Relational data model is the primary data model, which is used widely around the world for ___________ and ___________
(A) Creating
(B) Storing
(C) Retrieving
(D) Data storage
(E) Processing
(D) Data storage, (E) Processing

Question 4.
Relational data model is simple and has all the ___________ and ___________ required to process data with storage efficiency.
(A) Properties
(B) Capabilities
(C) Retrieving
(D) Data storage
(E) Processing
(A) Properties, (B) Capabilities

Question 5.
A table consists of information which is stored under different headings, called as ___________ or ___________
(A) Properties
(B) Fields
(C) Capabilities
(D) Retrieving
(E) Columns
(B) Fields, (E) Columns

Question 6.
Table consists of ___________ and ___________
(A) Properties
(B) Fields
(C) Capabilities
(D) Columns
(E) Rows
(D) Columns, (E) Rows

Question 7.
A Database consists of one or more ___________ according to which ___________ is stored in a table.
(A) Tables
(B) Data
(C) Capabilities
(D) Columns
(E) Rows
(A) Tables, (B) Data

Question 8.
Database designer decides the name of the ___________ and ___________ of columns.
(A) Schema
(B) Table
(C) Fields
(D) Titles
(E) Capabilities
(B) Table, (D) Titles

Question 9.
Data Definition Language statements or commands are used to define and modify the database structure of your ___________ or ___________
(A) Table
(B) Schema
(C) Fields
(D) Titles
(E) Capabilities
(A) Table, (B) Schema

5. Multiple Choice Three Correct Answers.

Question 1.
Database Management System stores data in such a way that it becomes easier to ___________, ___________ and ___________
(A) Retrieve
(B) Hierarchical
(C) Manipulate
(D) Update Information
(E) Network
(A) Retrieve, (C) Manipulate, (D) Update Information

Question 2.
There are different data models like ___________ model, ___________ model and ___________ model.
(A) Network
(B) Hierarchical
(C) Relational
(D) Retrieve
(E) Manipulate
(A) Network, (B) Hierarchical, (C) Relational

Question 3.
There are 3 types of relationships in relational database design ___________, ___________ & ___________
(A) Retrieve
(B) Manipulate
(C) One-to-One
(D) One-to-Many (or Many-to-One)
(E) Many-to-Many
(C) One-to-One, (D) One-to-Many (or Many-to-One), (E) Many-to-Many

Question 4.
SQL is Structured Query Language, which is a computer language for ___________, ___________ and ___________ data stored in a relational database.
(A) Relational
(B) Storing
(C) Manipulating
(D) Retrieving
(E) Network
(B) Storing, (C) Manipulating, (D) Retrieving

6. Match the following.

Question 1.

 Column ‘A’ Column ‘B’ (1) Database (A) Raw facts (2) Data (B) Creating and managing databases (3) Information (C) Collection of interrelated data (4) DBMS (D) Processed data

 Column ‘A’ Column ‘B’ (1) Database (C) Collection of interrelated data (2) Data (A) Raw facts (3) Information (D) Processed data (4) DBMS (B) Creating and managing databases

Question 2.

 Column ‘A’ Column ‘B’ (1) Advantages of DBMS (A) Authorised users (2) Data integrity (B) Data is accurate and consistent (3) Data Security (C) Reducing Data Redundancy (4) Backup and Recovery (D) Restores the database

 Column ‘A’ Column ‘B’ (1) Advantages of DBMS (C) Reducing Data Redundancy (2) Data integrity (B) Data is accurate and consistent (3) Data Security (A) Authorised users (4) Backup and Recovery (D) Restores the database

Question 3.

 Column ‘A’ Column ‘B’ (1) CHAR (A) It is used for storing integer values (2) VARCHAR (B) It can represent numbers (3) DECIMAL (C) Holds a variable-length string (4) INT (D) Holds a fixed-length string

 Column ‘A’ Column ‘B’ (1) CHAR (D) Holds a fixed-length string (2) VARCHAR (C) Holds a variable-length string (3) DECIMAL (B) It can represent numbers (4) INT (A) It is used for storing integer values

Question 4.

 Column ‘A’ Column ‘B’ (1) DATE (A) It holds the date (2) TIME (B) It holds time (3) Model (C) Logical structure of database (4) Relational data model (D) Primary data model

 Column ‘A’ Column ‘B’ (1) DATE (A) It holds the date (2) TIME (B) It holds time (3) Model (C) Logical structure of database (4) Relational data model (D) Primary data model

Question 5.

 Column ‘A’ Column ‘B’ (1) Atomicity (A) Successfully committed transaction (2) Consistency (B) Completed successfully (3) Isolation (C) Persists in case of a system failure (4) Durability (D) Operate independently

 Column ‘A’ Column ‘B’ (1) Atomicity (B) Completed successfully (2) Consistency (A) Successfully committed transaction (3) Isolation (D) Operate independently (4) Durability (C) Persists in case of a system failure

Question 6.

 Column ‘A’ Column ‘B’ (1) RDBMS (A) Storage unit in a Relational database (2) Table (B) Collection of interrelated data (3) Database designer (C) Tuple (4) Record (D) Decides the name of the table and titles of Columns

 Column ‘A’ Column ‘B’ (1) RDBMS (B) Collection of interrelated data (2) Table (A) Storage unit in a Relational database (3) Database designer (D) Decides the name of the table and titles of Columns (4) Record (C) Tuple

Question 7.

 Column ‘A’ Column ‘B’ (1) Primary Key (A) Managing data within tables (2) Structured Query Language (B) Uniquely identify each row (3) Data Definition Language (C) Storing, manipulating, and retrieving data (4) Data Manipulation Language (D) Define and modify the database

 Column ‘A’ Column ‘B’ (1) Primary Key (B) Uniquely identify each row (2) Structured Query Language (C) Storing, manipulating, and retrieving data (3) Data Definition Language (D) Define and modify the database (4) Data Manipulation Language (A) Managing data within tables

Question 8.

 Column ‘A’ Column ‘B’ (1) SELECT (A) Extracts data from a table (2) UPDATE (B) Updates data in a table (3) DELETE (C) Deletes data from a table (4) INSERT INTO (D) Insert data into a table

 Column ‘A’ Column ‘B’ (1) SELECT (A) Extracts data from a table (2) UPDATE (B) Updates data in a table (3) DELETE (C) Deletes data from a table (4) INSERT INTO (D) Insert data into a table

Question 1.
What are Database and DBMS?

1. A Database is often abbreviated as DB.
2. A database is a collection of interrelated data.
3. Full form of DBMS is Database Management System
4. A Database Management System is software for creating and managing databases.
5. The Database Management System provides users and programmers with a systematic way to create, retrieve, update and manage data.

Question 2.
Discuss the various Data types.

1. CHAR holds a fixed-length string (can contain letters, numbers, and special characters).
2. VARCHAR holds a variable-length string (can contain letters, numbers, and special characters).
3. DECIMAL can represent numbers with or without the fractional part.
4. INT is used for storing integer values.
5. DATE holds the date including day, month, and year.
6. TIME() holds time. Format: HH:MM:SS.

Question 3.
Explain Data Model and Relational Model.

1. This logical structure of the database is known as a Model.
2. The data model defines how the data is connected to each other and how they are processed and stored inside the system.
3. The data model describes the method of storing and retrieving the data.
4. The relational data model is the primary data model, which is used widely around the world for data storage and processing.
5. The relational data model is simple and has all the properties and capabilities required to process data with storage efficiency.

Question 4.
Write down the Properties of Transactions.

1. Atomicity ensures that all operations within the work unit are completed successfully.
2. Consistency ensures that the database properly changes states upon a successfully committed transaction.
3. Isolation enables transactions to operate independently of and be transparent to each other.
4. Durability ensures that the result or effect of a committed transaction persists in case of a system failure.

Question 5.
Explain the concept of RDBMS.

1. RDBMS stands for Relational Database Management System.
2. In Relational Database Management System a database is considered as a collection of interrelated data.

Question 6.
Discuss the basic database concept.

1. The Table is the basic data storage unit in a Relational database.
2. The table consists of columns and rows.
3. A database consists of one or more tables according to which data is stored in a table.
4. The database designer decides the name of the table and the titles of columns.
5. A record is composed of fields and contains all the data about one particular person, company, or item in a database.
6. Record is also called a Tuple,
7. A column or a combination of columns that can be used to identify one or more rows (tuples) in a table is called a Key of the table.
8. The group of one or more columns used to uniquely identify each row of a relation is called its Primary Key.
9. Foreign Key is a field (or collection of fields) in one table that refers to the Primary Key in another table.

Question 7.
Explain Relationships in the database.

1. Relationships link data from individual tables to increase the usefulness of the database.
2. A Relationship in the context of databases is a situation that exists between two relational database tables.

Question 8.
Discuss the types of relationships in Relational Database Design.

1. In a One-to-One relationship, one record in a table is associated with one and only one record in another table.
2. One-to-Many relationships can also be viewed as Many-to-One relationships, depending on which way you look at them.
3. A Many-to-Many relationship occurs when multiple records in a table are associated with multiple records in another table.

Question 9.
What is SQL and categories of SQL commands?

1. The full form of SQL is Structured Query Language.
2. Structured Query Language is the standard language for Relational Database Management Systems.
3. The full form of DDL is Data Definition Language.
4. Data Definition Language statements or commands are used to define and modify the database structure of your tables or schema.
5. The full form of DML is Data Manipulation Language.
6. Data Manipulation Language statements or commands are used for managing data within tables.
7. The full form of DCL is Data Control Language.
8. Data Control Language is used to control user access in a database.

## Maharashtra Board Class 11 Information Technology Important Questions Chapter 1 Basics of Information Technology

Balbharati Maharashtra State Board Class 11 Information Technology Important Questions Chapter 1 Basics of Information Technology Important Questions and Answers.

## Maharashtra State Board 11th Information Technology Important Questions Chapter 1 Basics of Information Technology

1. Fill in the Blanks.

Question 1.
______________ encompasses all of the technologies that we use in order to create, collect, process, protect and store information.
Information Technology

Question 2.
______________ refers to hardware, software (computer programs), and computer networks.
Information Technology

Question 3.
Full form of ICT is ______________
Information and Communication Technology

Question 4.
______________ concept involves transfer and use of all kinds of information.
Information and Communication Technology

Question 5.
______________ is the foundation of economy and a driving force of social changes in the 21st century.
Information and Communication Technology

Question 6.
______________ can be any character, text, word, number or raw facts.
Data

Question 7.
______________ is data formatted in a manner that allows it to be utilized by human beings in some significant way.
Information

Question 8.
The word Computer is derived from a Latin word ______________
Computare

Question 9.
An electronic device which accepts input from the user, processes it according to the instructions given to it and gives the required result in the form of output, is a ______________
Computer

Question 10.
A ______________ can process data, images, audio, video and graphics.
Computer

Question 11.
______________ accepts data or instructions by way of input.
Computer

Question 12.
______________ stores data.
Computer

Question 13.
______________ can process data as required by the user.
Computer

Question 14.
______________ gives results in the form of output.
Computer

Question 15.
______________ controls all operations inside a computer.
Computer

Question 16.
______________ is a specification detailing of how a set of software and hardware technology standards interact to form a computer system.
Computer Architecture

Question 17.
______________ refers to how a computer system is designed and how it works.
Computer Architecture

Question 18.
______________ helps users to enter data and commands into a computer system.
Input unit

Question 19.
The main function of ______________ devices is to direct commands and data into computer.
Input

Question 20.
______________ is an input device that enters numbers and characters.
Keyboard

Question 21.
A ______________ can be an input device for entering directions and commands.
Mouse

Question 22.
Full form of CPU is ______________
Central Processing Unit

Question 23.
After receiving data and commands from users, a computer system has to process it according to the instructions provided. Here, it has to rely on a component called the ______________
Central Processing Unit

Question 24.
The ______________ further uses these three elements Arithmetic and Logic Unit, Control Unit and Memory Unit.
Central Processing Unit

Question 25.
Full form of ALU is ______________
Arithmetic and Logic Unit

Question 26.
______________ part of the CPU performs arithmetic operations.
Arithmetic and Logic Unit

Question 27.
______________ can even perform logical functions like the comparison of data.
Arithmetic and Logic Unit

Question 28.
______________ is the back bone of computers.
Control Unit

Question 29.
______________ is responsible for coordinating tasks between all components of a computer system.
Control Unit

Question 30.
The ______________ collects data from input units and sends it to processing units depending on its nature.
Control Unit

Question 31.
______________ transmits processed data to output units to facilitate users.
Control Unit

Question 32.
Once a user enters data using input devices, the computer system stores this data in its ______________
Memory Unit

Question 33.
The ______________ uses a set of pre-programmed instructions to further transmit this data to other parts of the CPU.
Memory Unit

Question 34.
______________ is internal memory of the computer.
Primary Memory

Question 35.
______________ is also known as main memory.
Primary Memory

Question 36.
______________ holds the data and instruction on which computer is currently working.
Primary Memory

Question 37.
RAM stands for ______________
Random Access Memory

Question 38.
______________ is known as read/write memory.
Random Access Memory

Question 39.
______________ is generally referred to as main memory of the computer system.
Random Access Memory

Question 40.
______________ is a temporary memory.
Random Access Memory

Question 41.
______________ is also called as Volatile Memory.
Random Access Memory

Question 42.
ROM stands for ______________

Question 43.
______________ is a Permanent Type memory.

Question 44.
______________ cannot be overwritten by the computer.

Question 45.
______________ is also called Non-Volatile Memory.

Question 46.
______________ is an external memory of the computer.
Secondary Memory

Question 47.
______________ is used to store the huge amount of different programs and information.
Secondary Memory

Question 48.
______________ basically reproduce the data formatted by the computer for user’s benefit.
Output Unit

Question 49.
______________ is a binary digit that holds only one of two values.
Bit

Question 50.
A group of 4 bits is called a ______________
Nibble

Question 51.
A group of 8 bits is called a ______________
Byte

Question 52.
A ______________ is the smallest unit, which can represent a data item or a character.
Byte

Question 53.
1 Byte is ______________
8 Bits

Question 54.
1 KiloByte (KB) is ______________
1,024 Bytes

Question 55.
1 MegaByte (MB) is ______________
1,024 KiloBytes

Question 56.
1 GigaByte (GB) is ______________
1,024 MegaBytes

Question 57.
1 TeraByte (TB) is ______________
1,024 GigaBytes

Question 58.
1 PetaByte (PB) is ______________
1,024 TeraBytes

Question 59.
1 ExaByte (EB) is ______________
1,024 PetaBytes

Question 60.
______________ comprises of the physical components that a computer system requires to function.
Computer hardware

Question 61.
A set of instructions given to the computer is known as a ______________
Program

Question 62.
Program or set of programs are called as ______________
Software

Question 63.
______________ is a generic term used to describe computer programs.
Software

Question 64.
______________ refers to the software which releases code in public domain for anyone to use.
Open source software

Question 65.
Full form of FOSS ______________
Free Open Source Software Policy

Question 66.
______________ and it enabled them to save some millions of rupees each year in licensing costs.
Free Open Source Software Policy

Question 67.
In case of ______________, user has to purchase the software before using it.
Closed Source Software

Question 68.
______________ is a program or group of programs designed for end users.
Application Software

Question 69.
______________ is also called end-user programs.
Application Software

Question 70.
______________ is a set of instructions required for a computer to work.
System Software

Question 71.
______________ is a program that allows different applications and various components of hardware.
Linux Operating System

Question 72.
A computer would not be able to function correctly without an ______________
Operating System

Question 73.
An ______________ is a software program that empowers the computer hardware to communicate and operate with the computer software.
Operating System

Question 74.
The ______________ boots up the computer and makes sure that everything is operational.
Operating System

Question 75.
The ______________ is also what runs the cell phone and most of the electronic devices.
Operating System

Question 76.
The ______________ usually come preloaded on any computer, tablet, laptop or cell phone that user buy.
Operating System

Question 77.
Full form of DOS is ______________
Disk Operating System

Question 78.
______________ is a series of operating systems that are designed by Microsoft.
Windows

Question 79.
______________ is the most commonly used operating system.
Windows

Question 80.
Apple Corporation’s registered operating system is called ______________
Mac OS

Question 81.
______________ is an open-source operating system created by Google.
Chrome OS

Question 82.
______________ is an open-source, portable, multi- multiprogramming, operating system.
Linux

Question 83.
______________ is a free and open-source operating system for mobile phones provided by Google.
Android

Question 84.
______________ is used by Nokia phones. This is closed source OS.
Asha

Question 85.
______________ is a closed source operating system for smartphone and tablet devices.
Blackberry

Question 86.
______________ is Apple’s closed source operating system for Apple’s iPhone, iPod Touch, iPad and second-generation Apple TVs.
Iphone Operating System

Question 87.
______________ Phone is developed by Microsoft as a closed source operating system for mobile phones.
Windows

Question 88.
______________ is used as the predominantly backbone of the Internet.
Linux

Question 89.
______________ is one of the most popular GNU/Linux distribution.
Ubuntu

Question 90.
Full form of GUI is ______________
Graphical User Interface

Question 91.
Full form of CLI ______________
Command Line Interface

Question 92.
The ______________ is when the user interacts with the computer using images, icons, and dialog boxes.
Graphical User Interface

Question 93.
The ______________ option is used for quick search of the application.
Search

Question 94.
The ______________ folder is where all the personal documents and settings are stored.
Home

Question 95.
The ______________ is when user interacts with the computer using text.
Command Line Interface

Question 96.
The ______________ are programs that are run when user types command name.
Commands

Question 97.
______________ is Free and Open Source.
Linux

Question 98.
______________ Operating System is free from viruses.
Linux

Question 99.
______________ Operating Systems can update themselves.
Proprietary

Question 100.
______________ is a collection of software for a Linux distribution on the server.
Repositories

Question 101.
The ______________ manager updates the operating system as well as other softwares periodically.
Package

Question 102.
______________ is a group of interconnected computers or devices to have communication within themselves.
Computer Network

Question 103.
A ______________ consists of a collection of computers, printers and other equipment that is connected together.
Computer Network

Question 104.
Full form of LAN is ______________
Local Area Network

Question 105.
Full form of MAN is ______________
Metropolitan Area Network

Question 106.
Full form of WAN is ______________
Wide Area Network

Question 107.
______________ type of network covers the smallest area.
Local Area Network

Question 108.
______________ covers an area larger than LAN.
Metropolitan Area Network

Question 109.
______________ type of network comprises the largest of all.
Wide Area Network

Question 110.
In ______________ usage area is limited to areas such as an office building, home, hospital, schools, etc.
Local Area Network

Question 111.
______________ covers a short distance, and so the error and noise are minimized.
Local Area Network

Question 112.
______________ type of network is easy to setup.
Local Area Network

Question 113.
In ______________ data transmits at a very fast rate as the number of computers linked are limited.
Local Area Network

Question 114.
______________ is a less expensive hardware and maintenance cost is also low.
Local Area Network

Question 115.
______________ connects two or more separate computers that reside in the same or different cities.
Metropolitan Area Network

Question 116.
Full for of ISP is ______________
Internet Service Provider

Question 117.
______________ covers a large geographical area and may serve as an ISP.
Metropolitan Area Network

Question 118.
______________ type of network is hard to design and maintain.
Metropolitan Area Network

Question 119.
______________ is a computer network that extends over a large geographical area.
Wide Area Network

Question 120.
In ______________ type of network the technology is high speed and relatively expensive.
Wide Area Network

Question 121.
A Communication medium used for ______________ is Telephone Network or Satellite Link.
Wide Area Network

Question 122.
______________ is the design of a computer network.
Network Architecture

Question 123.
A ______________ network has no dedicated servers.
Peer-to-Peer

Question 124.
______________ type of architecture is most suitable for larger network.
Client-Server

Question 125.
A computer which is seeking any resource from another computer is a ______________ computer.
Client

Question 126.
If a computer has a resource which is served to another computer, it is a ______________ computer.
Server

Question 127.
______________ means connecting computer to any other computer anywhere in the world.
Internet

Question 128.
The ______________ is generally defined as a global network connecting millions of computers.
Internet

Question 129.
The ______________ is a massive network of networks, a networking infrastructure.
Internet

Question 130.
With the help of the ______________, one can easily be in touch with anyone in the whole world by sending electronic mail, by chatting.
Internet

Question 131.
It can be said that ______________ provides a very strong connection or network between computers globally.
Internet

Question 132.
Full form of ARPANET is ______________

Question 133.
The first workable prototype of the internet came in the late 1960’s with the creation of ______________

Question 134.
______________ used packet switching to allow multiple computers to communicate on a single network.

Question 135.
Full form of TCP/IP is ______________
Transmission Control Protocol and Internet Protocol

Question 136.
______________ communications model that set standards for how data could be transmitted between multiple networks.
Transmission Control Protocol and Internet Protocol

Question 137.
Full form of WWW is ______________
World Wide Web

Question 138.
Tim Berners-Lee invented the ______________
World Wide Web

Question 139.
A ______________ is a set of rules that governs the communications between computers on a network.
Protocol

Question 140.
______________ breaks down the message into packets and sends them out into the network.
Transmission Control Protocol & Internet Protocol

Question 141.
Full form of DNS is ______________
Domain Name System

Question 142.
______________ translates network address into terms understood by humans and vice-versa.
Domain Name System

Question 143.
DHCP stands for ______________
Dynamic Host Configuration Protocol

Question 144.
Dynamic Host Configuration Protocol

Question 145.
FTP stands for ______________
File Transfer Protocol

Question 146.
______________ is used to transfer and manipulate files on the internet.
File Transfer Protocol

Question 147.
Full form of HTTP is ______________
Hyper Text Transfer Protocol

Question 148.
______________ is an internet-based protocol for sending and receiving web pages.
Hyper Text Transfer Protocol

Question 149.
Full form of IMAP is ______________
Internet Message Access Protocol

Question 150.
______________ is used for receiving e-mail messages from server on the Internet.
Internet Message Access Protocol

Question 151.
______________ maintains a copy of all the emails on server.
Internet Message Access Protocol

Question 152.
Full form of IRC is ______________
Internet Relay Chat

Question 153.
______________ facilitates communication in the form of text.
Internet Relay Chat

Question 154.
POP3 stands for ______________
Post Office Protocol Version 3

Question 155.
______________ is used for receiving e-mail from remote mail servers.
Post Office Protocol Version 3

Question 156.
______________ is used for sending e-mail messages to the Server on the Internet.
Simple Mail Transfer Protocol

Question 157.
Full form of ITES is ______________
IT Enabled Services

Question 158.
IT Enabled Services (ITES), also called as ______________
Web Enabled Services

Question 159.
______________ covers the entire amount of operations which exploit Information Technology for improving efficiency of an organization.
IT Enabled Services

Question 160.
______________ can develop interactive websites using knowledge of HTML, PHP and various other programming languages.
Web Designer

Question 161.
It is possible to have career as a ______________ with the scripting skills.
Software Developer

Question 162.
After getting knowledge about Database management one can work as a ______________
Database Manager

Question 163.
______________ are responsible for ensuring that networks are watertight.
Information Security Analyst

Question 164.
______________ using computerized accounting software can successfully handle accounting work.
Professional Accountant

Question 165.
______________ after getting IT knowledge one can advise and guide others in investing the money in various investment schemes.

Question 166.
It is possible to become a successful ______________ using one’s own creation and innovation.
Animator

Question 167.
Perhaps one of the trendiest and most fun jobs in the sector, a ______________
Games Developer

Question 168.
As a career opportunity, to become an ______________, one should be good in tools such as Kdenlive, Audacity.
Audio/Video Editor

Question 169.
______________ is the study and practice of environmentally sustainable computing or IT.
Green Computing

Question 170.
The goals of ______________ are similar to green chemistry.
Green Computing

Question 171.
______________ is important for all classes of systems, ranging from handheld systems to largescale data centers.
Green Computing

Question 172.
Full form of IOT is ______________
Internet of Things

Question 173.
The ______________ is the network of physical devices, vehicles, home appliances, and other items embedded with electronics, software, sensors, actuators, and connectivity.
Internet of Things

Question 174.
______________ is the delivery of computing services over the internet.
Cloud Computing

Question 175.
______________ is the process of examining data sets in order to draw conclusions about the information.
Data Analytics

Question 176.
______________ technologies and techniques are widely used in commercial industries to enable organizations to make more-informed business decisions.
Data Analytics

Question 177.
______________ is intelligence demonstrated by machines, in contrast to the natural intelligence displayed by humans and other animals.
Artificial Intelligence

Question 178.
Computer science defines ______________ research as the study of “intelligent agents”.
Artificial Intelligence

Question 179.
______________ is the scientific study of algorithms and statistical models that computer systems use to effectively perform a specific task.
Machine Learning

Question 180.
______________ refers to data sets that are too large or complex for traditional data-processing application software.
Big Data

Question 181.
______________ is a growing list of records, called blocks, which are linked using cryptography.
Blockchain

2. True or False.

Question 1.
Information Technology encompasses all of the technologies that we use in order to create, collect, process, protect and store information.
True

Question 2.
Programmers refer to hardware, software (computer programs), and computer networks.
False

Question 3.
The full form of ICT is Information and Communication Technology:
True

Question 4.
The Computer Science concept involves the transfer and use of all kinds of information.
False

Question 5.
Information and Communication Technology is the foundation of the economy and a driving force of social changes in the 21st century.
True

Question 6.
Data can be any character, text, word, number, or raw facts.
True

Question 7.
The virus is data formatted in a manner that allows it to be utilized by human beings in some significant way.
False

Question 8.
The word Computer is derived from the Latin word Komptom.
False

Question 9.
An electronic device that accepts input from the user, processes it according to the instructions given to it, and gives the required result in the form of output, is a Typewriter.
False

Question 10.
A computer can process data, images, audio, video, and graphics.
True

Question 11.
Computer accepts data or instructions by way of input.
True

Question 12.
Computer stores data.
True

Question 13.
The computer can process data as required by the user.
True

Question 14.
The computer gives results in the form of output.
True

Question 15.
Machine controls all operations inside a computer.
False

Question 16.
Computer Architecture is a specification detailing how a set of software and hardware technology standards interact to form a computer system.
True

Question 17.
Website refers to how a computer system is designed and how it works.
False

Question 18.
Storage Unit helps users to enter data and commands into a computer system.
False

Question 19.
The main function of hardware devices is to direct commands and data into computers.
False

Question 20.
The keyboard is an input device that enters numbers and characters.
True

Question 21.
A Mouse can be an input device for entering directions and commands.
True

Question 22.
The full form of CPU is Central Processing Unit.
True

Question 23.
After receiving data and commands from users, a computer system has to process it according to the instructions provided. Here, it has to rely on a component called the Arithmetic and Logic Unit.
False

Question 24.
The Central Processing Unit further uses these three elements Arithmetic and Logic Unit, Control Unit, and Memory Unit.
True

Question 25.
The full form of ALU is the Arithmetic and Logic Unit.
True

Question 26.
The Control Unit part of the CPU performs arithmetic operations.
False

Question 27.
Arithmetic and Logic Unit can even perform logical functions like the comparison of data.
True

Question 28.
The arithmetic and Logic Unit is the backbone of computers.
False

Question 29.
The Control unit is responsible for coordinating tasks between all components of a computer system.
True

Question 30.
The Control Unit collects data from input units and sends it to processing units depending on its nature.
True

Question 31.
Control Unit transmits processed data to output units to facilitate users.
True

Question 32.
Once a user enters data using input devices, the computer system stores this data in its Control Unit.
False

Question 33.
The memory unit uses a set of pre-programmed instructions to further transmit this data to other parts of the CPU.
True

Question 34.
Secondary Memory is the internal memory of the computer.
False

Question 35.
Secondary Memory is also known as main memory.
False

Question 36.
Secondary Memory holds the data and instructions on which computer is currently working.
False

Question 37.
RAM stands for Random Access Memory.
True

Question 38.
Random Access Memory is known as reading/write memory.
True

Question 39.
Random Access Memory is generally referred to as the main memory of the computer system.
True

Question 40.
Random Access Memory is a temporary memory.
True

Question 41.
Read-Only Memory is also called Volatile Memory.
False

Question 42.
True

Question 43.
Random Access Memory is a Permanent Type of memory.
False

Question 44.
Random Access Memory cannot be overwritten by the computer.
False

Question 45.
Random Access Memory is also called Non-Volatile Memory.
False

Question 46.
Secondary Memory is an external memory of the computer.
True

Question 47.
Secondary Memory is used to store a huge amount of different programs and information.
True

Question 48.
Does the input Unit basically reproduce the data formatted by the computer for the user’s benefit?
False

Question 49.
A bit is a binary digit that holds only one of two values.
True

Question 50.
A group of 4 bits is called a Nibble.
True

Question 51.
A group of 8 bits is called a Kilobyte.
False

Question 52.
A Byte is the smallest unit, which can represent a data item or a character.
True

Question 53.
1 Byte is 8 Bits.
True

Question 54.
1 KiloByte (KB) is 1,024 Bytes.
True

Question 55.
1 MegaByte (MB) is 1 Terabyte.
False

Question 56.
1 GigaByte (GB) is 1024 bites.
False

Question 57.
1 TeraByte (TB) is 1,024 GigaBytes.
True

Question 58.
1 PetaByte (PB) is 1,024 TeraBytes.
True

Question 59.
1 ExaByte (EB) is 1024 Megabytes.
False

Question 60.
The program comprises the physical components that a computer system requires to function.
False

Question 61.
A set of instructions given to the computer is known as hardware.
False

Question 62.
Program or set of programs are called Hardware.
False

Question 63.
Hardware is a generic term used to describe computer programs.
False

Question 64.
Open-source software refers to the software which releases code in the public domain for anyone to use.
True

Question 65.
Full form of FOSS Free Open Source Software Policy.
True

Question 66.
Free Open Source Software Policy and it enabled them to save some millions of rupees each year in licensing costs.
True

Question 67.
In the case of Closed source software, a user has to purchase the software before using it.
True

Question 68.
The machine is a program or group of programs designed for end-users.
False

Question 69.
Hardware is also called end-user programs.
False

Question 70.
Pen Drive is a set of instructions required for a computer to work.
False

Question 71.
Linux Operating system is a program that allows different applications and various components of the hardware.
True

Question 72.
A computer would not be able to function correctly without an operating system.
True

Question 73.
An operating system is a software program that empowers the computer hardware to communicate and operate with the computer software.
True

Question 74.
The operating system boots up the computer and makes sure that everything is operational.
True

Question 75.
The operating system is also what runs the cell phone and most electronic devices.
True

Question 76.
The operating systems usually come preloaded on any computer, tablet, laptop, or cell phone that the user buys.
True

Question 77.
The full form of DOS is Disk Operating System.
True

Question 78.
Linux is a series of operating systems that are designed by Microsoft.
False

Question 79.
Windows is the most commonly used operating system.
True

Question 80.
Apple Corporation’s registered operating system is called Mac OS.
True

Question 81.
Chrome OS is an open-source operating system created by Google.
True

Question 82.
Linux is an open-source, portable, multi-multiprogramming, operating system.
True

Question 83.
Asha is a free and open-source operating system for mobile phones provided by Google.
False

Question 84.
Android is used by Nokia phones. This is a closed source OS.
False

Question 85.
Blackberry is a closed source operating system for smartphone and tablet devices.
True

Question 86.
Windows is Apple’s closed source operating system for Apple’s iPhone, iPod Touch, iPad, and second-generation Apple TVs.
False

Question 87.
IOS Phone is developed by Microsoft as a closed source operating system for mobile phones.
False

Question 88.
Linux is used as the predominant backbone of the Internet.
True

Question 89.
Ubuntu is one of the most popular GNU/Linux distributions.
True

Question 90.
The full form of GUI is Graphical User Interface.
True

Question 91.
Full form of CLI Command Line Interface.
True

Question 92.
The graphical user interface is when the user interacts with the computer using images, icons, and dialog boxes.
True

Question 93.
The Home option is used for a quick search of the application.
False

Question 94.
The Search folder is where all the personal documents and settings are stored.
False

Question 95.
The Command is when the user interacts with the computer using text.
False

Question 96.
The command-line interface is programs that are run when a user types the command name.
False

Question 97.
Proprietary is Free and Open Source.
False

Question 98.
Linux Operating System is free from viruses.
True

Question 99.
Repositories Operating Systems can update themselves.
False

Question 100.
The repository is a collection of software for a Linux distribution on the server.
True

Question 101.
The Package manager updates the operating system as well as other software periodically.
True

Question 102.
Local Area Network is a group of interconnected computers or devices to have communication within themselves.
False

Question 103.
A Metropolitan Area Network consists of a collection of computers, printers, and other equipment that is connected together.
False

Question 104.
The full form of LAN is the Local Area Network.
True

Question 105.
The full form of MAN is Metropolitan Area Network.
True

Question 106.
The full form of WAN is a Wide Area Network.
True

Question 107.
Wide Area Network type of network covers the smallest area.
False

Question 108.
Metropolitan Area Network covers an area larger than LAN.
True

Question 109.
Local Area Network type of network comprises the largest of all.
False

Question 110.
In Local Area Network, usage area is limited to areas such as an office building, home, hospital, schools, etc.
True

Question 111.
Metropolitan Area Network covers a short distance, and so the error and noise are minimized.
False

Question 112.
Local Area Network type of network is easy to set up.
True

Question 113.
In Local Area Network data transmits at a very fast rate as the number of computers linked is limited.
True

Question 114.
Local Area Network is less expensive hardware and maintenance cost is also low.
True

Question 115.
Metropolitan Area Network connects two or more separate computers that reside in the same or different cities.
True

Question 116.
Full for of ISP is Internet Service Provider.
True

Question 117.
Metropolitan Area Network covers a large geographical area and may serve as an ISP.
True

Question 118.
Metropolitan Area Network type of network is hard to design and maintain.3
True

Question 119.
A Wide Area Network is a computer network that extends over a large geographical area.
True

Question 120.
In the Wide Area Network type of network, the technology is high speed and relatively expensive.
True

Question 121.
A Communication medium used for Wide Area networks is Telephone networks or Satellite Link.
True

Question 122.
Client-Server is the design of a computer network.
False

Question 123.
A Peer-to-Peer network has no dedicated servers.
True

Question 124.
Client-Server type of architecture is most suitable for larger networks.
True

Question 125.
A computer that is seeking any resource from another computer is a Client computer.
False

Question 126.
If a computer has a resource that is served to another computer, it is a client computer.
False

Question 127.
Memory means connecting a computer to any other computer anywhere in the world.
False

Question 128.
The Internet is generally defined as a global network connecting millions of computers.
True

Question 129.
The Internet is a massive network of networks, a networking infrastructure.
True

Question 130.
With the help of the Internet, one can easily be in touch with anyone in the whole world by sending electronic mail, by chatting.
True

Question 131.
It can be said that services provide a very strong connection or network between computers globally.
False

Question 132.
The full form of ARPANET is Advanced Research Projects Agency Network.
True

Question 133.
The first workable prototype of the internet came in the late 1960s with the creation of HTML.
False

Question 134.
Packets used packet switching to allow multiple computers to communicate on a single network.
False

Question 135.
The full form of TCP/IP is Transmission Control Protocol and Internet Protocol.
True

Question 136.
HTML communications model that set standards for how data could be transmitted between multiple networks.
False

Question 137.
The full form of WWW is World Wide Web.
True

Question 138.
Tim Berners-Lee invented the World Wide Web.
True

Question 139.
A DNS is a set of rules that governs the communications between computers on a network. Protocol.
False

Question 140.
Transmission Control Protocol & Internet Protocol breaks down the message into packets and sends them out into the network.
True

Question 141.
The full form of DNS is Domain Name System.
True

Question 142.
Protocol translates network address into terms understood by humans and vice-versa.
False

Question 143.
DHCP stands for Dynamic Host Configuration Protocol.
True

Question 144.
False

Question 145.
FTP stands for File Transfer Protocol.
True

Question 146.
HTTP is used to transfer and manipulate files on the internet.
False

Question 147.
The full form of HTTP is HyperText Transfer Protocol.
True

Question 148.
HyperText Transfer Protocol is an internet-based protocol for sending and receiving web pages.
True

Question 149.
The full form of IMAP is Internet Message Access Protocol.
True

Question 150.
FTP is used for receiving e-mail messages from servers on the Internet.
False

Question 151.
HTTP maintains a copy of all the emails on the server.
False

Question 152.
The full form of IRC is Internet Relay Chat.
True

Question 153.
FTP facilitates communication in the form of text.
False

Question 154.
POP3 stands for Post Office Protocol Version 3.
True

Question 155.
Post Office Protocol Version 3 is used for receiving e-mail from remote mail servers.
True

Question 156.
Simple Mail Transfer Protocol is used for sending e-mail messages to the Server on the Internet.
True

Question 157.
The full form of ITES is IT Enabled Services.
True

Question 158.
IT Enabled Services (ITES), also called as Information Technology.
False

Question 159.
IT Enabled Services covers the entire amount of operations that exploit Information Technology for improving the efficiency of an organization.
True

Question 160.
Database Manager can develop interactive websites using knowledge of HTML, PHP, and various other programming languages.
False

Question 161.
It is possible to have a career as a Financial Advisor with scripting skills.
False

Question 162.
After getting knowledge about Database management one can work as a Web Designer.
False

Question 163.
Professional Accountant is responsible for ensuring that networks are watertight.
False

Question 164.
Information Security Analyst using computerized accounting software can successfully handle accounting work.
False

Question 165.
Software developers after getting IT knowledge one can advise and guide others in investing the money in various investment schemes.
False

Question 166.
It is possible to become a successful Animator using one’s own creation and innovation.
True

Question 167.
Perhaps one of the trendiest and most fun jobs in the sector, a games developer.
True

Question 168.
As a career opportunity, to become an Audio/Video Editor, one should be good at tools such as Kdenlive, Audacity.
True

Question 169.
Internet of Things is the study and practice of environmentally sustainable computing or IT.
False

Question 170.
The goals of Cloud Computing are similar to green chemistry.
False

Question 171.
Green computing is important for all classes of systems, ranging from handheld systems to large-scale data centers.
True

Question 172.
The full form of IoT is the Internet of Things.
True

Question 173.
Data Analytics is the network of physical devices, vehicles, home appliances, and other items embedded with electronics, software, sensors, actuators, and connectivity.
False

Question 174.
Artificial Intelligence is the delivery of computing services over the internet.
False

Question 175.
Machine Learning is the process of examining data sets in order to draw conclusions about the information.
False

Question 176.
Data analytics technologies and techniques are widely used in commercial industries to enable organizations to make more informed business decisions.
True

Question 177.
Artificial Intelligence is intelligence demonstrated by machines, in contrast to the natural intelligence displayed by humans and other animals.
True

Question 178.
Computer science defines Blockchain research as the study of “intelligent agents”.
False

Question 179.
Machine Learning is the scientific study of algorithms and statistical models that computer systems use to effectively perform a specific task.
True

Question 180.
Big Data refers to data sets that are too large or complex for traditional data-processing application software.
True

Question 181.
Blockchain is a growing list of records, called blocks, which are linked using cryptography.
True

3. Multiple Choice Question (Single Choice)

Question 1.
______________ encompasses all of the technologies that we use in order to create, collect, process, protect and store information.
(A) Information Technology
(B) Hardware
(C) Software
(D) System
(A) Information Technology

Question 2.
______________ refers to hardware, software (computer programs), and computer networks.
(A) Hardware
(B) Software
(C) Information Technology
(D) Computer Programs
(C) Information Technology

Question 3.
Full form of ICT is ______________
(A) Information and Computer Technology
(B) Internet and Communication Technology
(C) Information and Communication Technology
(D) Information and Carrier Technology
(C) Information and Communication Technology

Question 4.
______________ concept involves transfer and use of all kinds of information.
(A) Information and Computer Technology
(B) Internet and Communication Technology
(C) Information and Communication Technology
(D) Information and Carrier Technology
(C) Information and Communication Technology

Question 5.
______________ is the foundation of economy and a driving force of social changes in the 21st century.
(A) Information and Computer Technology
(B) Internet and Communication Technology
(C) Information and Communication Technology
(D) Information and Carrier Technology
(C) Information and Communication Technology

Question 6.
______________ can be any character, text, word, number or raw facts.
(A) Character
(B) Data
(C) Text
(D) Facts
(B) Data

Question 7.
______________ is data formatted in a manner that allows it to be utilized by human beings in some significant way
(A) Information
(B) Information Technology
(C) System
(D) Programming
(A) Information

Question 8.
The word Computer is derived from a Latin word ______________
(A) Computare
(B) Audio
(C) Video
(D) Graphics
(A) Computare

Question 9.
An electronic device that accepts input from the user, processes it according to the instructions given to it, and gives the required result in the form of output, is a ______________
(A) Audio
(B) Video
(C) Graphics
(D) Computer
(D) Computer

Question 10.
A ______________ can process data, images, audio, video and graphics.
(A) Audio
(B) Video
(C) Graphics
(D) Computer
(D) Computer

Question 11.
______________ accepts data or instructions by way of input.
(A) Audio
(B) Video
(C) Graphics
(D) Computer
(D) Computer

Question 12.
______________ stores data.
(A) Audio
(B) Video
(C) Graphics
(D) Computer
(D) Computer

Question 13.
______________ can process data as required by the user.
(A) Audio
(B) Video
(C) Graphics
(D) Computer
(D) Computer

Question 14.
______________ gives results in the form of output.
(A) Audio
(B) Video
(C) Graphics
(D) Computer
(D) Computer

Question 15.
______________ controls all operations inside a computer.
(A) Audio
(B) Video
(C) Graphics
(D) Computer
(D) Computer

Question 16.
______________ is a specification detailing of how a set of software and hardware technology standards interact to form a computer system.
(A) Computer Architecture
(B) Hardware
(C) Software
(D) System
(A) Computer Architecture

Question 17.
______________ refers to how a computer system is designed and how it works.
(A) Computer Architecture
(B) Hardware
(C) Software
(D) System
(A) Computer Architecture

Question 18.
______________ helps users to enter data and commands into a computer system.
(A) Keyboard
(B) Mouse
(C) Input Unit
(D) Input
(C) Input Unit

Question 19.
The main function of ______________ devices is to direct commands and data into computer.
(A) Keyboard
(B) Mouse
(C) Input Unit
(D) Input
(D) Input

Question 20.
______________ is an input device that enters numbers and characters.
(A) Keyboard
(B) Mouse
(C) Input Unit
(D) Input
(A) Keyboard

Question 21.
A ______________ can be an input device for entering directions and commands.
(A) Keyboard
(B) Mouse
(C) Input Unit
(D) Input
(B) Mouse

Question 22.
Full full for CPU is ______________
(A) Central Processing Unit
(B) Computer Processing Unit
(C) Central Programmer Unit
(D) Computer Programmer Unit
(A) Central Processing Unit

Question 23.
After receiving data and commands from users, a computer system has to process it according to the instructions provided. Here, it has to rely on a component called the ______________
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory Unit
(A) Central Processing Unit

Question 24.
The ______________ further uses these three elements Arithmetic and Logic Unit, Control Unit and Memory Unit.
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory unit
(A) Central Processing Unit

Question 25.
Full form of ALU is ______________
(A) Asian Learning Unit
(B) Arithmetic and Logic Unit
(C) Arithmetic Learning Unit
(D) Arithmetic Lesson unit
(B) Arithmetic and Logic Unit

Question 26.
______________ part of the CPU performs arithmetic operations.
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory unit
(B) Arithmetic and Logic Unit

Question 27.
______________ can even perform logical functions like the comparison of data.
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory unit
(B) Arithmetic and Logic Unit

Question 28.
______________ is the backbone of computers.
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory Unit
(C) Control Unit

Question 29.
______________ responsible for coordinating tasks between all components of a computer system.
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory unit
(C) Control Unit

Question 30.
The ______________ collects data from input units and sends it to processing units depending on its nature.
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory Unit
(C) Control Unit

Question 31.
______________ transmits processed data to output units to facilitate users.
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory Unit
(C) Control Unit

Question 32.
Once a user enters data using input devices, the computer system stores this data in its ______________
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory unit
(D) Memory Unit

Question 33.
The ______________ uses a set of pre-programmed instructions to further transmit this data to other parts of the CPU.
(A) Central Processing Unit
(B) Arithmetic and Logic Unit
(C) Control Unit
(D) Memory Unit
(D) Memory Unit

Question 34.
______________ is internal memory of the computer.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory
(A) Primary memory

Question 35.
______________ is also known as main memory.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory
(A) Primary memory

Question 36.
______________ holds the data and instruction on which computer is currently working.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory
(A) Primary Memory

Question 37.
RAM stands for ______________
(A) Random Access Memory
(C) Ram Access Memory
(D) Random Access Machine
(A) Random Access Memory

Question 38.
______________ is known as read/write memory.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory
(B) Random Access Memory

Question 39.
______________ is generally referred to as main memory of the computer system.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory
(B) Random Access Memory

Question 40.
______________ is a temporary memory.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory
(B) Random Access Memory

Question 41.
______________ is also called as Volatile Memory.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory
(B) Random Access Memory

Question 42.
ROM stands for ______________
(C) Rom Only Memory
(D) Ram Only Memory

Question 43.
______________ is a Permanent Type memory.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory

Question 44.
______________ cannot be overwritten by the computer.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory

Question 45.
______________ is also called Non-Volatile Memory.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory

Question 46.
______________ is an external memory of the computer.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory
(D) Secondary Memory

Question 47.
______________ is used to store the huge amount of different programs and information.
(A) Primary memory
(B) Random Access Memory
(D) Secondary Memory
(D) Secondary Memory

Question 48.
______________ basically reproduce the data formatted by the computer for user’s benefit.
(A) Output unit
(B) Bit
(C) Nibble
(D) Byte
(A) Output unit

Question 49.
______________ is a binary digit that holds only one of two values.
(A) Output unit
(B) Bit
(C) Nibble
(D) Byte
(B) Bit

Question 50.
A group of 4 bits is called a ______________
(A) Output unit
(B) Bit
(C) Nibble
(D) Byte
(C) Nibble

Question 51.
A group of 8 bits is called a ______________
(A) Output unit
(B) Bit
(C) Nibble
(D) Byte
(D) Byte

Question 52.
A ______________ is the smallest unit, which can represent a data item or a character.
(A) Output unit
(B) Bit
(C) Nibble
(D) Byte
(D) Byte

Question 53.
1 Byte is ______________
(A) 8 Bits
(B) 1,024 Bytes
(C) 1,024 KiloBytes
(D) 1,024 MegaBytes
(A) 8 Bits

Question 54.
1 KiloByte (KB) is ______________
(A) 8 Bits
(B) 1,024 Bytes
(C) 1,024 KiloBytes
(D) 1,024 MegaBytes
(B) 1,024 Bytes

Question 55.
1 MegaByte (MB) is ______________
(A) 8 Bits
(B) 1,024 Bytes
(C) 1,024 KiloBytes
(D) 1,024 MegaBytes
(C) 1,024 KiloBytes

Question 56.
1 GigaByte (GB) is ______________
(A) 8 Bits
(B) 1,024 Bytes
(C) 1,024 KiloBytes
(D) 1,024 MegaBytes
(D) 1,024 MegaBytes

Question 57.
1 TeraByte (TB) is ______________
(A) 1,024 GigaBytes
(B) 1,024 TeraBytes
(C) 1,024 PetaBytes
(D) MegaBytes
(A) 1,024 GigaBytes

Question 58.
1 PetaByte (PB) is ______________
(A) 1,024 GigaBytes
(B) 1,024 TeraBytes
(C) 1,024 PetaBytes
(D) MegaBytes
(B) 1,024 TeraBytes

Question 59.
1 ExaByte (EB) is ______________
(A) 1,024 GigaBytes
(B) 1,024 TeraBytes
(C) 1,024 PetaBytes
(D) MegaBytes
(C) 1,024 PetaBytes

Question 60.
______________ comprises of the physical components that a computer system requires to function.
(A) Computer hardware
(B) Program
(C) Software
(D) Open source software
(A) Computer hardware

Question 61.
A set of instructions given to the computer is known as a ______________
(A) Computer hardware
(B) Program
(C) Software
(D) Open source software
(B) Program

Question 62.
Program or set of programs are called as ______________
(A) Computer hardware
(B) Program
(C) Software
(D) Open source software
(C) Software

Question 63.
______________ is a generic term used to describe computer programs.
(A) Computer hardware
(B) Program
(C) Software
(D) Open source software
(C) Software

Question 64.
______________ refers to the software which releases code in public domain for anyone to use.
(A) Computer hardware
(B) Program
(C) Software
(D) Open source software
(D) Open source software

Question 65.
Full form of FOSS ______________
(A) Free Open Source Software Policy
(B) Free Open System Source Policy
(C) Free Open Source System Policy
(D) First Open Source Software Policy
(A) Free Open Source Software Policy

Question 66.
______________ and it enabled them to save some millions of rupees each year in licensing costs.
(A) Free Open Source Software Policy
(B) Free Open System Source Policy
(C) Free Open Source System Policy
(D) First Open Source Software Policy
(A) Free Open Source Software Policy

Question 67.
In case of ______________, user has to purchase the software before using it.
(A) Free Open Source Software Policy
(B) Free Open System Source Policy
(C) Free Open Source System Policy
(D) Closed Source Software
(D) Closed Source Software

Question 68.
______________ is a program or group of programs designed for end-users.
(A) Application Software
(B) System Software
(C) Linux Operating system
(D) Operating system
(A) Application Software

Question 69.
______________ is also called end-user programs.
(A) Application Software
(B) System Software
(C) Linux Operating system
(D) Operating system
(A) Application Software

Question 70.
______________ is a set of instructions required for a computer to work.
(A) Application Software
(B) System Software
(C) Linux Operating system
(D) Operating system
(B) System Software

Question 71.
______________ is a program that allows different applications and various components of hardware.
(A) Application Software
(B) System Software
(C) Linux Operating System
(D) Operating system
(C) Linux Operating System

Question 72.
A computer would not be able to function correctly without an ______________
(A) Application Software
(B) System Software
(C) Linux Operating System
(D) Operating System
(D) Operating System

Question 73.
An ______________ is a software program that empowers the computer hardware to communicate and operate with the computer software.
(A) Application Software
(B) System Software
(C) Linux Operating System
(D) Operating System
(D) Operating System

Question 74.
The ______________ boots up the computer and makes sure that everything is operational.
(A) Application Software
(B) System Software
(C) Linux Operating System
(D) Operating System
(D) Operating System

Question 75.
The ______________ is also what runs the cell phone and most of the electronic devices.
(A) Application Software
(B) System Software
(C) Linux Operating system
(D) Operating System
(D) Operating System

Question 76.
The ______________ usually come preloaded on any computer, tablet, laptop or cell phone that user buy.
(A) Application Software
(B) System Software
(C) Linux Operating System
(D) Operating System
(D) Operating System

Question 77.
Full form of DOS is ______________
(A) Disk Operating System
(B) Disk Open System
(C) Dynamic Operating System
(D) Dynamic Open System
(A) Disk Operating System

Question 78.
______________ is a series of operating systems that are designed by Microsoft.
(A) Windows
(B) Mac OS
(C) Chrome OS
(D) Linux
(A) Windows

Question 79.
______________ is the most commonly used operating system.
(A) Windows
(B) Mac OS
(C) Chrome OS
(D) Linux
(A) Windows

Question 80.
Apple Corporation’s registered operating system is called ______________
(A) Windows
(B) Mac OS
(C) Chrome OS
(D) Linux
(B) Mac OS

Question 81.
______________ is an open-source operating system created by Google.
(A) Windows
(B) Mac OS
(C) Chrome OS
(D) Linux
(C) Chrome OS

Question 82.
______________ is an open-source, portable, multi-multiprogramming, operating system.
(A) Windows
(B) Mac OS
(C) Chrome OS
(D) Linux
(D) Linux

Question 83.
______________ is a free and open source operating system for mobile phones provided by Google.
(A) Android
(B) Asha
(C) Blackberry
(D) IOS
(A) Android

Question 84.
______________ is used by Nokia phones. This is closed source OS.
(A) Android
(B) Asha
(C) Blackberry
(D) IOS
(B) Asha

Question 85.
______________ is a closed source operating system for smartphone and tablet devices.
(A) Android
(B) Asha
(C) Blackberry
(D) IOS
(C) Blackberry

Question 86.
______________ is Apple’s closed source operating system for Apple’s iPhone, iPod Touch, iPad and second-generation Apple TVs.
(A) Android
(B) Asha
(C) Blackberry
(D) iPhone Operating System
(D) Iphone Operating System

Question 87.
______________ Phone is developed by Microsoft as a closed source operating system for mobile phones.
(A) Windows
(B) Android
(C) Linux
(D) Ubuntu
(A) Windows

Question 88.
______________ is used as the predominantly backbone of the Internet.
(A) Windows
(B) Android
(C) Linux
(D) Ubuntu
(C) Linux

Question 89.
______________ is one of the most popular GNU/Linux distribution.
(A) Windows
(B) Android
(C) Linux
(D) Ubuntu
(D) Ubuntu

Question 90.
Full form of GUI is ______________
(A) Graphical User Interface
(B) Graphic Using Internet
(C) Game Using Internet
(D) Game User Internet
(A) Graphical User Interface

Question 91.
Full form of CLI ______________
(A) Command Line Internet
(B) Command Line Interface
(C) Central Line Interface
(D) Computer Line Interface
(B) Command Line Interface

Question 92.
The ______________ is when the user interacts with the computer using images, icons, and dialog boxes.
(A) Graphical User Interface
(B) Command Line Interface
(C) Search
(D) Home
(A) Graphical User Interface

Question 93.
The ______________ option is used for quick search of the application.
(A) Graphical User Interface
(B) Command Line Interface
(C) Search
(D) Home
(C) Search

Question 94.
The ______________ folder is where all the personal documents and settings are stored.
(A) Graphical User Interface
(B) Command Line Interface
(C) Search
(D) Home
(D) Home

Question 95.
The ______________ is when user interacts with the computer using text.
(A) Graphical User Interface
(B) Command Line Interface
(C) Search
(D) Home
(B) Command Line Interface

Question 96.
The ______________ are programs that are run when user types command name.
(A) Commands
(B) Graphical User Interface
(C) Search
(D) Home
(A) Commands

Question 97.
______________ is Free and Open Source.
(A) Linux
(B) Proprietary
(C) Repositories
(D) Package
(A) Linux

Question 98.
______________ Operating System is free from viruses.
(A) Linux
(B) Proprietary
(C) Repositories
(D) Package
(A) Linux

Question 99.
______________ Operating Systems can update themselves.
(A) Linux
(B) Proprietary
(C) Repositories
(D) Package
(B) Proprietary

Question 100.
______________ is a collection of software for a Linux distribution on the server.
(A) Linux
(B) Proprietary
(C) Repositories
(D) Package
(C) Repositories

Question 101.
The ______________ manager updates the operating system as well as other softwares periodically.
(A) Linux
(B) Proprietary
(C) Repositories
(D) Package
(D) Package

Question 102.
______________ is a group of interconnected computers or devices to have communication within themselves.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(A) Computer Network

Question 103.
A ______________ consists of a collection of computers, printers and other equipment that is connected together.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(A) Computer Network

Question 104.
Full form of LAN is ______________
(A) Local Area Network
(B) Local Access Network
(C) Live Area Network
(D) Live Access Network
(A) Local Area Network

Question 105.
Full form of MAN is ______________
(A) Metropolitan Area Network
(B) Metropolitan Access network
(C) Mobile Area Network
(D) Mobile Access Network
(A) Metropolitan Area Network

Question 106.
Full form of WAN is ______________
(A) Wide Area Network
(B) World Area Network
(C) Wonder Area Network
(D) Wide Access Network
(A) Wide Area Network

Question 107.
______________ type of network covers the smallest area.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(B) Local Area Network

Question 108.
______________ covers an area larger than LAN.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(D) Metropolitan Area Network

Question 109.
______________ type of network comprises the largest of all.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(C) Wide Area Network

Question 110.
In ______________ usage area is limited to areas such as an office building, home, hospital, schools, etc.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(B) Local Area Network

Question 111.
______________ covers a short distance, and so the error and noise are minimized.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(B) Local Area Network

Question 112.
______________ type of network is easy to setup.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(B) Local Area Network

Question 113.
In ______________ data transmits at a very fast rate as the number of computers linked are limited.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(B) Local Area Network

Question 114.
______________ is a less expensive hardware and maintenance cost is also low.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(B) Local Area Network

Question 115.
______________ connects two or more separate computers that reside in the same or different cities.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(D) Metropolitan Area Network

Question 116.
Full for of ISP is ______________
(A) Internet Service Provider
(B) International Service Provider
(C) Indian Server Provider
(D) Internet Server Provider
(A) Internet Service Provider

Question 117.
______________ covers a large geographical area and may serve as an ISP.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(D) Metropolitan Area Network

Question 118.
______________ type of network is hard to design and maintain.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(D) Metropolitan Area Network

Question 119.
______________ is a computer network that extends over a large geographical area.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(C) Wide Area Network

Question 120.
In ______________ type of network the technology is high speed and relatively expensive.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(C) Wide Area Network

Question 121.
A Communication medium used for ______________ is Telephone Network or Satellite Link.
(A) Computer Network
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(C) Wide Area Network

Question 122.
______________ is the design of a computer network.
(A) Network architecture
(B) Peer-to-Peer
(C) Client-Server
(D) Client
(A) Network Architecture

Question 123.
A ______________ network has no dedicated servers.
(A) Network architecture
(B) Peer-to-Peer
(C) Client-Server
(D) Client
(B) Peer-to-Peer

Question 124.
______________ type of architecture is most suitable for larger network.
(A) Network architecture
(B) Peer-to-Peer
(C) Client-Server
(D) Client
(C) Client-Server

Question 125.
A computer which is seeking any resource from another computer is a ______________ computer.
(A) Network architecture
(B) Peer-to-Peer
(C) Client-Server
(D) Client
(D) Client

Question 126.
If a computer has a resource which is served to another computer, it is a ______________ computer.
(A) Server
(B) Peer-to-Peer
(C) Client-Server
(D) Client
(A) Server

Question 127.
______________ means connecting computer to any other computer anywhere in the world.
(A) Internet
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(A) Internet

Question 128.
The ______________ is generally defined as a global network connecting millions of computers.
(A) Internet
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(A) Internet

Question 129.
The ______________ is a massive network of networks, a networking infrastructure.
(A) Internet
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(A) Internet

Question 130.
With the help of the ______________, one can easily be in touch with anyone in the whole world by sending electronic mail, by chatting.
(A) Internet
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(A) Internet

Question 131.
It can be said that ______________ provides a very strong connection or network between computers globally.
(A) Internet
(B) Local Area Network
(C) Wide Area Network
(D) Metropolitan Area Network
(A) Internet

Question 132.
Full form of ARPANET is ______________
(A) Advanced Research Projects Agency Network
(B) Advanced Research Project Area Network
(C) Advanced Research Project Access Network
(D) Advance Recovery Project Area Network
(A) Advanced Research Projects Agency Network

Question 133.
The first workable prototype of the internet came in the late 1960’s with the creation of ______________
(A) Advanced Research Projects Agency Network
(B) Transmission Control Protocol and Internet Protocol
(C) World Wide Web
(D) Local Area Network
(A) Advanced Research Projects Agency Network

Question 134.
______________ used packet switching to allow multiple computers to communicate on a single network.
(A) Advanced Research Projects Agency Network
(B) Transmission Control Protocol and Internet Protocol
(C) World Wide Web
(D) Local Area Network
(A) Advanced Research Projects Agency Network

Question 135.
Full form of TCP/IP is ______________
(A) Transmission Control Protocol and Internet Protocol
(B) Transfer Control Protocol and Internet Protocol
(D) Transfer Control Process and Internet Password
(A) Transmission Control Protocol and Internet Protocol

Question 136.
______________ communications model that set standards for how data could be transmitted between multiple networks.
(A) Advanced Research Projects Agency Network
(B) Transmission Control Protocol and Internet Protocol
(C) World Wide Web
(D) Local Area Network
(B) Transmission Control Protocol and Internet Protocol

Question 137.
Full form of WWW is ______________
(A) World Wide Website
(B) Web Wide World
(C) World Wide Web
(D) Wide Web World
(C) World Wide Web

Question 138.
Tim Berners-Lee invented the ______________
(A) Advanced Research Projects Agency Network
(B) Transmission Control Protocol and Internet Protocol
(C) World Wide Web
(D) Local Area Network
(C) World Wide Web

Question 139.
A ______________ is a set of rules that governs the communications between computers on a network.
(A) Protocol
(B) Transmission Control Protocol & Internet Protocol
(C) Domain Name System
(D) Dynamic Host Configuration Protocol
(A) Protocol

Question 140.
______________ breaks down the message into packets and sends them out into the network.
(A) Protocol
(B) Transmission Control Protocol & Internet Protocol
(C) Domain Name System
(D) Dynamic Host Configuration Protocol
(B) Transmission Control Protocol & Internet Protocol

Question 141.
Full form of DNS is ______________
(A) Domain Name System
(B) Dynamic Name System
(C) Domain Name Service
(D) Dynamic Name Service
(A) Domain Name System

Question 142.
______________ translates network address into terms understood by humans and vice-versa.
(A) Protocol
(B) Transmission Control Protocol & Internet Protocol
(C) Domain Name System
(D) Dynamic Host Configuration Protocol
(C) Domain Name System

Question 143.
DHCP stands for ______________
(A) Dynamic Host Configuration Protocol
(B) Domain Host Configuration Protocol
(C) Dynamic Host Configuration Process
(D) Domain Host Configuration Process
(A) Dynamic Host Configuration Protocol

Question 144.
(A) Protocol
(B) Transmission Control Protocol & Internet Protocol
(C) Domain Name System
(D) Dynamic Host Configuration Protocol
(D) Dynamic Host Configuration Protocol

Question 145.
FTP stands for ______________
(A) File Transfer Protocol
(B) File Transfer Process
(C) File Time Pass
(D) File Time Protocol
(A) File Transfer Protocol

Question 146.
______________ is used to transfer and manipulate files on the internet.
(A) File Transfer Protocol
(B) HyperText Transfer Protocol
(C) Internet Message Access Protocol
(D) Internet Relay Chat
(A) File Transfer Protocol

Question 147.
Full form of HTTP is ______________
(A) Hyper Text Transfer Protocol
(B) Hyper Test Transfer Protocol
(C) Hyper Transfer Text
(D) Hyper Text Transfer Process
(A) Hyper Text Transfer Protocol

Question 148.
______________ is an internet-based protocol for sending and receiving web pages.
(A) File Transfer Protocol
(B) Hyper Text Transfer Protocol
(C) Internet Message Access Protocol
(D) Internet Relay Chat
(B) Hyper Text Transfer Protocol

Question 149.
Full form of IMAP is ______________
(A) Internet Message Access Protocol
(B) Internet Message Access Process
(C) Internet Message Access Program
(D) Information Message Access Protocol
(A) Internet Message Access Protocol

Question 150.
______________ is used for receiving e-mail messages from server on the Internet.
(A) File Transfer Protocol
(B) HyperText Transfer Protocol
(C) Internet Message Access Protocol
(D) Internet Relay Chat
(C) Internet Message Access Protocol

Question 151.
______________ maintains a copy of all the emails on server.
(A) File Transfer Protocol
(B) Hyper Text Transfer Protocol
(C) Internet Message Access Protocol
(D) Internet Relay Chat
(C) Internet Message Access Protocol

Question 152.
Full form of IRC is ______________
(A) Internet Relay Chat
(B) International Relay Chat
(C) Internet Regional Chat
(D) Internet Random Chat
(A) Internet Relay Chat

Question 153.
______________ facilitates communication in the form of text.
(A) File Transfer Protocol
(B) Hyper Text Transfer Protocol
(C) Internet Message Access Protocol
(D) Internet Relay Chat
(D) Internet Relay Chat

Question 154.
POP3 stands for ______________
(A) Post Office Protocol Version 3
(B) Post Office Process Version 3
(C) Protocol Office Post Version 3
(D) Process Office Protocol Version 3
(A) Post Office Protocol Version 3

Question 155.
______________ is used for receiving e-mail from remote mail servers.
(A) File Transfer Protocol
(B) Hyper Text Transfer Protocol
(C) Internet Message Access Protocol
(D) Post Office Protocol Version 3
(D) Post Office Protocol Version 3

Question 156.
______________ is used for sending e-mail messages to the Server on the Internet.
(A) File Transfer Protocol
(B) Hyper Text Transfer Protocol
(C) Internet Message Access Protocol
(D) Simple Mail Transfer Protocol
(D) Simple Mail Transfer Protocol

Question 157.
Full form of ITES is ______________
(A) IT Enabled Services
(B) IT Encrypted Service
(C) IT Essential Service
(D) IT Safe Service
(A) IT Enabled Services

Question 158.
IT Enabled Services (ITES), also called as ______________
(A) Web Enabled Services
(B) Word Enabled Services
(C) Wide Enabled Services
(D) Web Engineer Services
(A) Web Enabled Services

Question 159.
______________ covers the entire amount of operations which exploit Information Technology for improving efficiency of an organization.
(A) File Transfer Protocol
(B) Hyper Text Transfer Protocol
(C) Internet Message Access Protocol
(D) IT Enabled Services
(D) IT Enabled Services

Question 160.
______________ can develop interactive websites using knowledge of HTML, PHP and various
other programming languages.
(A) Web Designer
(B) Software Developer
(C) Database Manager
(D) Information Security Analyst
(A) Web Designer

Question 161.
It is possible to have career as a ______________ with the scripting skills.
(A) Web Designer
(B) Software Developer
(C) Database Manager
(D) Information Security Analyst
(B) Software Developer

Question 162.
After getting knowledge about Database management one can work as a ______________
(A) Web Designer
(B) Software Developer
(C) Database Manager
(D) Information Security Analyst
(C) Database Manager

Question 163.
______________ are responsible for ensuring that networks are watertight.
(A) Web Designer
(B) Software Developer
(C) Database Manager
(D) Information Security Analyst
(D) Information Security Analyst

Question 164.
______________ using computerized accounting software can successfully handle accounting work.
(A) Professional Accountant
(C) Animator
(D) Games Developer
(A) Professional Accountant

Question 165.
______________ after getting IT knowledge one can advise and guide others in investing the money in various investment schemes.
(A) Professional Accountant
(C) Animator
(D) Games Developer

Question 166.
It is possible to become a successful ______________ using one’s own creation and innovation.
(A) Professional Accountant
(C) Animator
(D) Games Developer
(C) Animator

Question 167.
Perhaps one of the trendiest and most fun jobs in the sector, a ______________
(A) Professional Accountant
(C) Animator
(D) Games Developer
(D) Games Developer

Question 168.
As a career opportunity, to become an ______________, one should be good in tools such as Kdenlive, Audacity.
(A) Professional Accountant
(C) Animator
(D) Audio/Video Editor
(D) Audio/Video Editor

Question 169.
______________ is the study and practice of environmentally sustainable computing or IT.
(A) Green Computing
(B) Internet of Things
(C) Cloud Computing
(D) Data Analytics
(A) Green Computing

Question 170.
The goals of ______________ are similar to green chemistry
(A) Green Computing
(B) Internet of Things
(C) Cloud Computing
(D) Data Analytics
(A) Green Computing

Question 171.
______________ is important for all classes of systems, ranging from handheld systems to largescale data centers.
(A) Green Computing
(B) Internet of Things
(C) Cloud Computing
(D) Data Analytics
(A) Green Computing

Question 172.
Full form of IOT is ______________
(A) Internet of Time
(B) Internet of Things
(C) International of Time
(D) Intelligent of Things
(B) Internet of Things

Question 173.
The ______________ is the network of physical devices, vehicles, home appliances, and other items embedded with electronics, software, sensors, actuators, and connectivity.
(A) Green Computing
(B) Internet of Things
(C) Cloud Computing
(D) Data Analytics
(B) Internet of Things

Question 174.
______________ is the delivery of computing services over the internet.
(A) Green Computing
(B) Internet of Things
(C) Cloud Computing
(D) Data Analytics
(C) Cloud Computing

Question 175.
______________ is the process of examining data sets in order to draw conclusions about the information.
(A) Green Computing
(B) Internet of Things
(C) Cloud Computing
(D) Data Analytics
(D) Data Analytics

Question 176.
______________ technologies and techniques are widely used in commercial industries to enable
organizations to make more-informed business decisions.
(A) Green Computing
(B) Internet of Things
(C) Cloud Computing
(D) Data Analytics
(D) Data Analytics

Question 177.
______________ is intelligence demonstrated by machines, in contrast to the natural intelligence displayed by humans and other animals.
(A) Artificial Intelligence
(B) Machine Learning
(C) Big Data
(D) Blockchain
(A) Artificial Intelligence

Question 178.
Computer science defines ______________ research as the study of “intelligent agents”.
(A) Artificial Intelligence
(B) Machine Learning
(C) Big Data
(D) Blockchain
(A) Artificial Intelligence

Question 179.
______________ is the scientific study of algorithms and statistical models that computer systems use to effectively perform a specific task.
(A) Artificial Intelligence
(B) Machine Learning
(C) Big Data
(D) Blockchain
(B) Machine Learning

Question 180.
______________ refers to data sets that are too large or complex for traditional data-processing application software.
(A) Artificial Intelligence
(B) Machine Learning
(C) Big Data
(D) Blockchain
(C) Big Data

Question 181.
______________ is a growing list of records, called blocks, which are linked using cryptography.
(A) Artificial Intelligence
(B) Machine Learning
(C) Big Data
(D) Blockchain
(D) Blockchain

4. Multiple Choice Two Correct Answer.

Question 1.
Computer Architecture is a specification detailing of how a set of ______________ and ______________ technology standards interact to form a computer system
(A) Software
(B) Numbers
(C) Data
(D) Commands
(E) Hardware
(A) Software (E) Hardware

Question 2.
Input unit helps users to enter ______________ and ______________ into a computer system.
(A) Software
(B) Numbers
(C) Data
(D) Commands
(E) Hardware
(C) Data (D) Commands

Question 3.
The main function of input devices is to ______________ and ______________ into computer.
(A) Software
(B) Numbers
(C) Direct Commands
(D) Data
(E) Hardware
(C) Direct Commands (D) Data

Question 4.
Keyboard is an input device that enters ______________ and ______________
(A) Software
(B) Numbers
(C) Data
(D) Characters
(E) Hardware
(B) Numbers (D) Characters

Question 5.
A Mouse can be an input device for entering ______________ and ______________
(A) Directions
(B) Commands
(C) Data
(D) Logical
(E) Comparison
(A) Directions (B) Commands

Question 6.
After receiving ______________ and ______________ from users, a computer system has to process it according to the instructions provided. Here, it has to rely on a component called the Central Processing Unit.
(A) Directions
(B) Commands
(C) Data
(D) Logical
(E) Comparison
(B) Commands (C) Data

Question 7.
Arithmetic and Logic Unit can even perform ______________ functions like the ______________ of data.
(A) Directions
(B) Commands
(C) Data
(D) Logical
(E) Comparison
(D) Logical (E) Comparison

Question 8.
There are two types of memory ______________ & ______________
(A) Primary Memory
(B) Random Access Memory
(C) Secondary Memory
(E) Data
(A) Primary Memory (C) Secondary Memory

Question 9.
Primary memory is generally of two types ______________ & ______________
(A) Primary Memory
(B) Random Access Memory
(C) Secondary Memory
(E) Data
(B) Random Access Memory (D) Read Only Memory

Question 10.
Primary Memory holds the ______________ and ______________ on which computer is currently working.
(A) Primary Memory
(B) Instruction
(C) Secondary Memory
(E) Data
(B) Instruction (E) Data

Question 11.
______________ and ______________ is often measured in Megabytes (MB) and Gigabytes (GB).
(A) Computer storage
(B) Megabytes (MB)
(C) Memory
(D) Gigabytes (GB)
(E) Data
(A) Computer storage (C) Memory

Question 12.
Computer storage and memory is often measured in ______________ and ______________
(A) Computer storage
(B) Megabytes (MB)
(C) Memory
(D) Gigabytes (GB)
(E) Data
(B) Megabytes (MB) (D) Gigabytes (GB)

Question 13.
A byte is the smallest unit, which can represent a ______________ item or a ______________
(A) Computer storage
(B) Character
(C) Memory
(D) Gigabytes (GB)
(E) Data
(B) Character (E) Data

Question 14.
Computer hardware comprises of the ______________ components that a computer system requires to ______________
(A) Application Software
(B) Physical
(C) System Software
(D) Function
(E) Hardware
(B) Physical (D) Function

Question 15.
Computer software can be classified into two types based on its utility ______________ & ______________
(A) Application Software
(B) Physical
(C) System Software
(D) Function
(E) Hardware
(A) Application Software (C) System Software

Question 16.
Linux Operating system is a program that allows different ______________ and various components of ______________
(A) Application
(B) Physical
(C) System Software
(D) Function
(E) Hardware
(A) Application (E) Hardware

Question 17.
An operating system is a software program that empowers the ______________ to communicate and operate with the ______________
(A) Application Software
(B) Physical
(C) Computer Hardware
(D) Function
(E) Computer Software
(C) Computer Hardware (E) Computer Software

Question 18.
Windows is a series of ______________ that are designed by ______________
(A) Operating Systems
(B) Open-Source Operating
(C) Microsoft
(E) Portable
(A) Operating Systems (C) Microsoft

Question 19.
Chrome OS is an ______________ system created by ______________
(A) Operating Systems
(B) Open-Source Operating
(C) Microsoft
(E) Portable

Question 20.
Linux is an open-source, ______________, ______________, operating system.
(A) Operating Systems
(B) Open-Source Operating
(C) Portable
(E) Multi-User-Multiprogramming
(C) Portable (E) Multi-User-Multiprogramming

Question 21.
Android is a free and ______________ for mobile phones provided by ______________
(A) Operating Systems
(B) Open-Source Operating
(C) Multi- Multiprogramming
(E) Portable

Question 22.
Asha is used by ______________ phones. This is ______________ OS.
(A) Nokia
(B) Microsoft
(C) Closed Source
(E) Multi-User
(A) Nokia (C) Closed Source

Question 23.
Blackberry is a closed source operating system for ______________ and ______________
(A) Smartphone
(B) Tablet Devices
(C) Microsoft
(E) Multi-User
(A) Smartphone (B)Tablet Devices

Question 24.
Windows Phone is developed by ______________ as a ______________ for mobile phones.
(A) Nokia
(B) Microsoft
(C) Closed Source Operating System
(E) Multi-User
(B) Microsoft (C) Closed Source Operating System

Question 25.
UNIX was trademarked in 1969 by a group of AT&T employees at Bell Labs as a ______________ and ______________ computer operating system.
(A) Smartphone
(B) Tablet Devices
(C) Microsoft
(E) Multi-User

Question 26.
The Search option is used for ______________ search of the ______________
(A) Quick
(B) Personal
(C) Application
(D) Settings
(E) Software
(A) Quick (C) Application

Question 27.
The Home folder is where all the ______________ documents and ______________ are stored.
(A) Quick
(B) Personal
(C) Application
(D) Settings
(E) Software
(B) Personal (D) Settings

Question 28.
Repositories is a collection of ______________ for a ______________ distribution on the server.
(A) Quick
(B) Software
(C) Application
(D) Settings
(E) Linux
(B) Software (E) Linux

Question 29.
The Package manager updates the ______________ as well as other ______________ periodically.
(A) Operating System
(B) Softwares
(C) Application
(D) Settings
(E) Linux
(A) Operating System (B) Softwares

Question 30.
Computer Network is a group of ______________ or ______________ to have communication within themselves.
(A) Interconnected Computers
(B) Devices
(C) High Speed
(D) Relatively Expensive
(E) Telephone Network
(A) Interconnected Computers (B) Devices

Question 31.
In Wide Area Network type of network the technology is ______________ and ______________
(A) Interconnected Computers
(B) Devices
(C) High Speed
(D) Relatively Expensive
(E) Telephone Network
(C) Highspeed (D) Relatively Expensive

Question 32.
A Communication medium used for WAN is ______________ or ______________
(A) Devices
(B) High Speed
(C) Relatively Expensive
(D) Telephone Network
(D) Telephone Network (E) Satellite Link

Question 33.
Two of the most widely used types of network architecture are ______________ and ______________
(A) Peer-to-Peer
(B) Devices
(C) Client/Server
(D) High Speed
(E) Relatively Expensive
(A) Peer-to-Peer (C) Client/Server

Question 34.
There are two types of machines in network, ______________ and ______________
(A) Client
(B) Devices
(C) Server
(D) High Speed
(E) Relatively Expensive
(A) Client (C) Server

Question 35.
The first workable prototype of the ______________ came in the late 1960’s with the creation of ______________
(A) Internet
(B) Advanced Research Projects Agency Network
(C) Packet
(D) Single
(E) Network
(A) Internet (B) Advanced Research Projects Agency Network

Question 36.
Advanced Research Projects Agency Network used ______________ switching to allow multiple computers to communicate on a ______________ network.
(A) Internet
(B) Advanced Research Projects Agency Network
(C) Packet
(D) Single
(E) Network
(C) Packet (D) Single

Question 37.
Transmission Control Protocol & Internet Protocol breaks down the message into ______________ and sends them out into the ______________
(A) Internet
(B) Advanced Research Projects Agency Network
(C) Packets
(D) Single
(E) Network
(C) Packets (E) Network

Question 38.
(A) Computers
(B) Internet
(C) Advanced Research Projects Agency Network
(D) Users
(E) Network
(A) Computers (D) Users

Question 39.
File Transfer Protocol is used to ______________ and ______________ files on the internet.
(A) Transfer
(B) Sending
(C) Manipulate
(D) Receiving
(E) HTML
(A) Transfer (C) Manipulate

Question 40.
HyperText Transfer Protocol is an internet-based protocol for ______________ and ______________ web pages.
(A) Transfer
(B) Sending
(C) Manipulate
(D) Receiving
(E) HTML
(B) Sending (D) Receiving

Question 41.
The outcome of an IT Enabled Service is in two forms ______________ & ______________
(A) Direct Improved Service
(B) Indirect Benefits
(C) Manipulate
(D) Receiving
(E) HTML
(A) Direct Improved Service (B) Indirect Benefits

Question 42.
Web Designer can develop interactive websites using knowledge of ______________, ______________ and various other programming languages.
(A) Direct Improved Service
(B) Indirect Benefits
(C) HTML
(D) Receiving
(E) PHP
(C) HTML (E) PHP

Question 43.
Professional Accountant using ______________ software can successfully handle ______________ work.
(A) Computerized Accounting
(B) Accounting
(C) HTML
(D) Receiving
(E) PHP
(A) Computerized Accounting (B) Accounting

Question 44.
It is possible to become a successful Animator using one’s own ______________ and ______________
(A) Creation
(B) Handheld
(C) Innovation
(D) Data
(E) Algorithms
(A) Creation (C) Innovation

Question 45.
Green computing is important for all classes of systems, ranging from ______________ systems to largescale ______________ centers.
(A) Creation
(B) Handheld
(C) Innovation
(D) Data
(E) Algorithms
(B) Handheld (D) Data

Question 46.
Machine Learning is the scientific study of ______________ and ______________ models that computer systems use to effectively perform a specific task.
(A) Creation
(B) Handheld
(C) Innovation
(D) Algorithms
(E) Statistical
(D) Algorithms (E) Statistical

Question 47.
Blockchain is a growing list of records, called ______________, which are linked using ______________
(A) Blocks
(B) Creation
(C) Handheld
(D) Innovation
(E) Cryptography
(A) Blocks (E) Cryptography

5. Multiple Choice Three Correct Answers.

Question 1.
Information technology refers to ______________, ______________, and ______________
(A) Hardware
(B) Input Unit
(C) Output Unit
(D) Software (computer programs)
(E) Computer Networks
(A) Hardware (D) Software (computer programs) (E) Computer networks

Question 2.
Computer Architecture is a specification detailing of how a set of ______________ and ______________ technology standards interact to form a ______________
(A) Software
(B) Hardware
(C) Computer System
(D) Input Unit
(E) Output Unit
(A) Software (B) Hardware (C) Computer System

Question 3.
Every computer system has the following three basic components ______________, ______________ & ______________
(A) Data
(B) Commands
(C) Input Unit
(D) Central Processing Unit
(E) Output Unit
(C) Input Unit (D) Central Processing Unit (E) Output Unit

Question 4.
Input unit helps users to enter ______________ and ______________ into a ______________
(A) Data
(B) Commands
(C) Input Unit
(D) Central Processing Unit
(E) Computer System
(A) Data (B) Commands (E) Computer System

Question 5.
The CPU further uses these three elements ______________, ______________ & ______________
(A) Arithmetic and Logic Unit
(B) Image
(C) Control Unit
(D) Memory Unit
(E) Icons
(A) Arithmetic and Logic Unit (C) Control Unit (D) Memory Unit

Question 6.
The graphical user interface is when the user interacts with the computer using ______________ , ______________, and ______________
(A) Images
(B) Icons
(C) Dialog Boxes
(D) Computers
(E) Printers
(A) Images (B) Icons (C) Dialog Boxes

Question 7.
A computer network consists of a collection of ______________, ______________ and ______________ that is connected together.
(A) Computers
(B) Printers
(C) Metropolitan Area Network
(D) Wide Area Network
(E) Other equipment
(A) Computers (B) Printers (E) Other equipment

Question 8.
______________, ______________ & ______________ are three types of network based on the geographical area they cover.
(A) Local Area Network
(B) Metropolitan Area Network
(C) Wide Area Network
(D) Web enabled services
(E) Remote services
(A) Local Area Network (B) Metropolitan Area Network (C) Wide Area Network

Question 9.
IT Enabled Services (ITES), also called ______________ or ______________ or ______________
(A) Local Area Network
(B) Wide Area Network
(C) Web Enabled Services
(D) Remote Services
(E) Tele-Working
(C) Web Enabled Services (D) Remote Services (E) Tele-Working

6. Match the following.

Question 1.

 Column ‘A’ Column ‘B’ (1) Computer (A) Input device (2) Keyboard (B) Computare (3) Arithmetic and Logic Unit (C) Arithmetic Operations (4) Memory Unit (D) Pre-programmed instructions

 Column ‘A’ Column ‘B’ (1) Computer (B) Computare (2) Keyboard (A) Input device (3) Arithmetic and Logic Unit (C) Arithmetic Operations (4) Memory Unit (D) Pre-programmed instructions

Question 2.

 Column ‘A’ Column ‘B’ (1) Primary Memory (A) Non-Volatile Memory (2) RAM (B) Volatile Memory (3) ROM (C) Internal memory (4) Binary Digit (D) 0 or 1

 Column ‘A’ Column ‘B’ (1) Primary Memory (C) Internal memory (2) RAM (B) Volatile Memory (3) ROM (A) Non-Volatile Memory (4) Binary Digit (D) 0 or 1

Question 3.

 Column ‘A’ Column ‘B’ (1) 4 bits (A) Software (2) 8 bits (B) Physical components (3) Computer hardware (C) Byte (4) Program or set of programs (D) Nibble

 Column ‘A’ Column ‘B’ (1) 4 bits (D) Nibble (2) 8 bits (C) Byte (3) Computer hardware (B) Physical components (4) Program or set of programs (A) Software

Question 4.

 Column ‘A’ Column ‘B’ (1) Open source software (A) Public domain (2) Closed source software (B) Purchase the software (3) Applications software (C) Operating system (4) System Software (D) End-user programs

 Column ‘A’ Column ‘B’ (1) Open source software (A) Public domain (2) Closed source software (B) Purchase the software (3) Applications software (D) End-user programs (4) System Software (C) Operating system

Question 5.

 Column ‘A’ Column ‘B’ (1) Apple Corporation’s (A) Mac OS (2) Google (B) Android (3) Asha (C) Nokia Phones (4) Microsoft (D) Windows Phone

 Column ‘A’ Column ‘B’ (1) Apple Corporation’s (A) Mac OS (2) Google (B) Android (3) Asha (C) Nokia Phones (4) Microsoft (D) Windows Phone

Question 6.

 Column ‘A’ Column ‘B’ (1) Ubuntu (A) Free from viruses (2) Linux Operating System (B) GNU/Linux (3) Repositories (C) Collection of Software

 Column ‘A’ Column ‘B’ (1) Ubuntu (B) GNU/Linux (2) Linux Operating System (A) Free from viruses (3) Repositories (C) Collection of Software

Question 7.

 Column ‘A’ Column ‘B’ (1) LAN (A) Covers the smallest area (2) MAN (B) The largest of all (3) WAN (C) Covers an area larger than LAN

 Column ‘A’ Column ‘B’ (1) LAN (A) Covers the smallest area (2) MAN (C) Covers an area larger than LAN (3) WAN (B) The largest of all

Question 8.

 Column ‘A’ Column ‘B’ (1) Peer-to-Peer Architecture (A) Connecting millions of computers (2) Client-Server Architecture (B) Client and server (3) Internet (C) World Wide Web (4) Tim Berners-Lee (D) Same Status

 Column ‘A’ Column ‘B’ (1) Peer-to-Peer Architecture (D) Same Status (2) Client-Server Architecture (B) Client and server (3) Internet (A) Connecting millions of computers (4) Tim Berners-Lee (C) World Wide Web

Question 9.

 Column ‘A’ Column ‘B’ (1) Domain Name System (A) Sending and receiving web pages (2) Dynamic Host Configuration Protocol (B) Transfer and manipulate files (3) File Transfer Protocol (C) Automatically assign internet addresses (4) HyperText Transfer Protocol (D) Translates Network Address

 Column ‘A’ Column ‘B’ (1) Domain Name System (D) Translates Network Address (2) Dynamic Host Configuration Protocol (C) Automatically assign internet addresses (3) File Transfer Protocol (B) Transfer and manipulate files (4) HyperText Transfer Protocol (A) Sending and receiving web pages

Question 10.

 Column ‘A’ Column ‘B’ (1) Internet Message Access Protocol (A) Receiving e-mail messages from the server (2) Internet Relay Chat (B) Used for Internet chat (3) Post Office Protocol Version 3 (C) Receiving an e-mail from remote mail servers (4) Simple Mail Transfer Protocol (D) Sending e-mail messages to the Server (5) Transmission Control Protocol & Internet Protocol (E) Breaks down the message into packets

 Column ‘A’ Column ‘B’ (1) Internet Message Access Protocol (A) Receiving e-mail messages from the server (2) Internet Relay Chat (B) Used for Internet chat (3) Post Office Protocol Version 3 (C) Receiving an e-mail from remote mail servers (4) Simple Mail Transfer Protocol (D) Sending e-mail messages to the Server (5) Transmission Control Protocol & Internet Protocol (E) Breaks down the message into packets

Question 11.

 Column ‘A’ Column ‘B’ (1) IT Enabled Services (ITES) (A) HTML & PHP (2) Web Designer and Developer (B) Web Enabled Services (3) Software Developer (C) Scripting Skill (4) Database Manager (D) SQL Skills

 Column ‘A’ Column ‘B’ (1) IT Enabled Services (ITES) (B) Web Enabled Services (2) Web Designer and Developer (A) HTML & PHP (3) Software Developer (C) Scripting Skill (4) Database Manager (D) SQL Skills

Question 12.

 Column ‘A’ Column ‘B’ (1) Information Security Analyst (A) Networks are watertight (2) Professional Accountant (B) Handle accounting work (3) Financial Advisor (C) Investing the money (4) Animator (D) Creation and innovation

 Column ‘A’ Column ‘B’ (1) Information Security Analyst (A) Networks are watertight (2) Professional Accountant (B) Handle accounting work (3) Financial Advisor (C) Investing the money (4) Animator (D) Creation and innovation

Question 13.

 Column ‘A’ Column ‘B’ (1) Green Computing (A) Computing Services (2) Internet of Things (IoT) (B) Network of Physical Devices (3) Cloud Computing (C) Green Chemistry (4) Data Analytics (D) Examining Data

 Column ‘A’ Column ‘B’ (1) Green Computing (C) Green Chemistry (2) Internet of Things (IoT) (B) Network of Physical Devices (3) Cloud Computing (A) Computing Services (4) Data Analytics (D) Examining Data

Question 14.

 Column ‘A’ Column ‘B’ (1) Artificial Intelligence (A) Blocks (2) Machine Learning (B) Too large or complex (3) Big Data (C) Algorithms and Statistical Models (4) Blockchain (D) Intelligent Agents

 Column ‘A’ Column ‘B’ (1) Artificial Intelligence (D) Intelligent Agents (2) Machine Learning (C) Algorithms and Statistical Models (3) Big Data (B) Too large or complex (4) Blockchain (A) Blocks

Question 1.
Define Information Technology.
Information Technology encompasses all of the technologies that we use in order to create, collect, process, protect and store information. Information Technology refers to “hardware, software (computer programs), and computer networks”.

Question 2.
Explain ICT.

• The full form of ICT is Information and Communication Technology.
• The information and Communication Technology concept involves the transfer and use of all kinds of information.
• Information and Communication Technology is the foundation of the economy and a driving force of social changes in the 21st century.

Question 3.
What are Data and Information?
Data can be any character, text, word, number, or raw facts.
Examples of Data:

Information is data formatted in a manner that allows it to be utilized by human beings in some significant way.
Examples of Information:
Maharashtra, 944444444114.

Question 4.
What is Computer and Computer System?

1. The word Computer is derived from the Latin word Computare.
2. An electronic device that accepts input from the user, processes it according to the instructions given to it, and gives the required result in the form of output, is a Computer.
3. The computer can process data, images, audio, video, and graphics.
4. Computer accepts data or instructions by way of input.
5. Computer stores data.
6. A computer can process data as required by the user.
7. The computer gives results in the form of output.
8. The computer controls all operations inside a computer.

Question 5.
What is Computer Architecture?

1. Computer Architecture is a specification detailing how a set of software and hardware technology standards interact to form a computer system.
2. Computer Architecture refers to how a computer system is designed and how it works.

Question 6.
Explain Input Unit

1. Input unit helps users to enter data and commands into a computer system.
2. The main function of input devices is to direct commands and data into the computer.
3. The keyboard is an input device that enters numbers and characters.
4. A mouse can be an input device for entering directions and commands.

Question 7.
Briefly explain the CPU and its element.

1. After receiving data and commands from users, a computer system has to process it according to the instructions provided. Here, it has to rely on a component called the Central Processing Unit.
2. The Central Processing Unit further uses these three elements Arithmetic and Logic Unit, Control Unit, and Memory Unit.
3. The full form of ALU is the Arithmetic and Logic Unit.
4. The arithmetic and Logic Unit part of the CPU performs arithmetic operations.
5. Arithmetic and Logic Unit can even perform logical functions like the comparison of data.
6. The Control Unit is the backbone of computers.
7. The Control Unit is responsible for coordinating tasks between all components of a computer system.
8. The Control Unit collects data from input units and sends it to processing units depending on its nature.
9. Control Unit transmits processed data to output units to facilitate users.
10. Once a user enters data using input devices, the computer system stores this data in its Memory unit.
11. The Memory unit uses a set of pre-programmed instructions to further transmit this data to other parts of the CPU.

Question 8.
Explain the types of memory.
There are two types of memory (1) Primary Memory (2) Secondary Memory

1. Primary Memory is the internal memory of the computer.
2. Primary Memory is also known as main memory.
3. Primary Memory holds the data and instructions on which computer is currently working.
4. RAM stands for Random Access Memory.
5. Random Access Memory is known as reading/write memory.
6. Random Access Memory is generally referred to as the main memory of the computer system.
7. Random Access Memory is a temporary memory.
8. Random Access Memory is also called Volatile Memory.
9. Read-Only Memory is a Permanent Type memory.
10. Read-Only Memory cannot be overwritten by the computer.
11. Read-Only Memory is also called Non-Volatile Memory.
12. Secondary Memory is an external memory of the computer.
13. Secondary Memory is used to store a huge amount of different programs and information.

Question 9.
What is the Output unit and units of memory?

1. Output units basically reproduce the data formatted by the computer for the user’s benefit.
2. The bit is a binary digit that holds only one of two values.
3. A group of 4 bits is called a Nibble.
4. A group of 8 bits is called a Byte.
5. A Byte is the smallest unit, which can represent a data item or a character.
6. 1 Byte is 8 Bits.
7. 1 KiloByte (KB) is 1,024 Bytes.
8. 1 MegaByte (MB) is 1,024 KiloBytes.
9. 1 GigaByte (GB) is 1,024 MegaBytes.
10. 1 TeraByte (TB) is 1,024 GigaBytes.
11. 1 PetaByte (PB) is 1,024 TeraBytes.
12. 1 ExaByte (EB) is 1,024 PetaBytes.

Question 10.
Explain concepts of hardware and software.

1. Computer hardware comprises the physical components that a computer system requires to function.
2. A set of instructions given to the computer is known as Program.
3. Program or set of programs are called Software.
4. Software is a generic term used to describe computer programs.
5. Open-source software refers to the software which releases code in the public domain for anyone to use.
6. The full form of FOSS is FOSS Free Open Source Software Policy.
7. Free Open Source Software Policy and enabled them to save some millions of rupees each year in licensing costs.
8. In the case of Closed Source Software user has to purchase the software before using it.

Question 11.
Write down the classification of software based on its utility.

1. Application software is a program or group of programs designed for end-users.
2. Applications software is also called end-user programs.
3. System Software is a set of instructions required for a computer to work.
4. Linux Operating system is a program that allows different applications and various components of the hardware.
5. A computer would not be able to function correctly without an operating system.
6. An operating system is a software program that empowers the computer hardware to communicate and operate with the computer software.
7. The operating system boots up the computer and makes sure that everything is operational.
8. The operating system is also what runs the cell phone and most electronic devices.
9. The operating systems usually come preloaded on any computer, tablet, laptop, or cell phone that the user buys.

Question 12.
Explain Operating Systems for Personal Computers and Mobile Phones.

1. The full form of DOS is Disk Operating System.
2. Windows is a series of operating systems that are designed by Microsoft.
3. Windows is the most commonly used operating system.
4. Apple Corporation’s registered operating system is called Mac OS.
5. Chrome OS is an open-source operating system created by Google.
6. Linux is an open-source, portable, multi- multiprogramming, operating system.
7. Android is a free and open-source operating system for mobile phones provided by Google.
8. Asha is used by Nokia phones. This is a closed source OS.
9. Blackberry is a closed source operating system for smartphone and tablet devices.
10. IOS is Apple’s closed source operating system for Apple’s iPhone, iPod Touch, iPad, and second-generation Apple TVs.
11. Windows Phone is developed by Microsoft as a closed source operating system for mobile phones.
12. Linux is used as the predominant backbone of the Internet.
13. Ubuntu is one of the most popular GNU/Linux distributions.

Question 13.
Explain GUI and CLI.

1. The full form of GUI is Graphical User Interface.
2. Full form of CLI Command Line Interface.
3. The graphical user interface is when the user interacts with the computer using images, icons, and dialog boxes.
4. The Search option is used for a quick search of the application.
5. The Home folder is where all the personal documents and settings are stored.
6. The Command-line interface is when the user interacts with the computer using text.
7. The Commands are programs that are run when a user types the command name.

Question 14.

1. Linux is Free and Open Source.
2. Linux Operating System is free from viruses.
3. Proprietary Operating Systems can update themselves.
4. The repository is a collection of software for a Linux distribution on the server.
5. The Package manager updates the operating system as well as other software periodically.

Question 15.
Define Computer networks and different types of networks.

1. Computer Network is a group of interconnected computers or devices to have communication within themselves.
2. A Computer Network consists of a collection of computers, printers, and other equipment that is connected together.
3. The full form of LAN is the Local Area Network.
4. The full form of MAN is Metropolitan Area Network.
5. The full form of WAN is a Wide Area Network.
6. Local Area Network type of network covers the smallest area.
7. Metropolitan Area Network covers an area larger than LAN.
8. Wide Area Network type of network comprises the largest of all.
9. In Local Area Network, usage area is limited to areas such as an office building, home, hospital, schools, etc.
10. Local Area Network covers a short distance, and so the error and noise are minimized.
11. Local Area Network type of network is easy to set up.
12. In Local Area Network data transmits at a very fast rate as the number of computers linked is limited.
13. Local Area Network is less expensive hardware and maintenance cost is also low.
14. Metropolitan Area Network connects two or more separate computers that reside in the same or different cities.
15. Full for of ISP is Internet Service Provider.
16. Metropolitan Area Network covers a large geographical area and may serve as an ISP.
17. Metropolitan Area Network type of network is hard to design and maintain.
18. A Wide Area Network is a computer network that extends over a large geographical area.
19. In the Wide Area Network type of network, the technology is high speed and relatively expensive.
20. A Communication medium used for Wide Area networks is Telephone networks or Satellite Link.

Question 16.
Explain Network Architecture.

1. Network architecture is the design of a computer network.
2. A Peer-to-Peer network has no dedicated servers.
3. Client-Server type of architecture is most suitable for larger networks.
4. A computer that is seeking any resource from another computer is a Client computer.
5. If a computer has a resource that is served to another computer, it is a Server computer.

Question 17.
What is Internet?

1. Internet means connecting a computer to any other computer anywhere in the world.
2. The Internet is generally defined as a global network connecting millions of computers.
3. The Internet is a massive network of networks, a networking infrastructure.
4. With the help of the Internet, one can easily be in touch with anyone in the whole world by sending electronic mail, by chatting.
5. It can be said that the Internet provides a very strong connection or network between computers globally.

Question 18.
Write down the history of the Internet.

1. The full form of ARPANET is Advanced Research Projects Agency Network.
2. The first workable prototype of the internet came in the late 1960s with the creation of the Advanced Research Projects Agency Network.
3. Advanced Research Projects Agency Network used packet switching to allow multiple computers to communicate on a single network.
4. The full form of TCP/ IP is Transmission Control Protocol and Internet Protocol.
5. Transmission Control Protocol and Internet Protocol communications model that set standards for how data could be transmitted between multiple networks.
6. The full form of WWW is World Wide Web.
7. Tim Berners-Lee invented the World Wide Web.

Question 19.
Define Protocol with examples.

1. A Protocol is a set of rules that governs the communications between computers on a network.
2. Transmission Control Protocol & Internet Protocol breaks down the message into packets and sends them out into the network.
3. The full form of DNS is Domain Name System.
4. Domain Name System translates network address into terms understood by humans and vice-versa.
5. DHCP stands for Dynamic Host Configuration Protocol.
7. FTP stands for File Transfer Protocol.
8. File Transfer Protocol is used to transfer and manipulate files on the internet.
9. The full form of HTTP is HyperText Transfer Protocol.
10. HyperText Transfer Protocol is an internet-based protocol for sending and receiving web pages.
11. The full form of IMAP is Internet Message Access Protocol.
12. Internet Message Access Protocol is used for receiving e-mail messages from servers on the Internet.
13. Internet Message Access Protocol maintains a copy of all the emails on the server.
14. The full form of IRC is Internet Relay Chat.
15. Internet Relay Chat facilitates communication in the form of text.
16. POP3 stands for Post Office Protocol Version 3.
17. Post Office Protocol Version 3 is used for receiving e-mail from remote mail servers.
18. Simple Mail Transfer Protocol is used for sending e-mail messages to the Server on the Internet.

Question 20.
Explain the meaning of ITES.

1. The full form of ITES is IT Enabled Services.
2. IT Enabled Services (ITES), also called as Web-Enabled Services.
3. IT Enabled Services covers the entire amount of operations that exploit Information Technology for improving the efficiency of an organization.

Question 21.
Discuss various careers opportunities in IT.

1. Web Designer can develop interactive websites using knowledge of HTML, PHP, and various other programming languages.
2. It is possible to have a career as a software developer with scripting skills.
3. After getting knowledge about Database management one can work as a Database Manager.
4. Information Security Analysts are responsible for ensuring that networks are watertight.
5. Professional Accountant using computerized accounting software can successfully handle accounting work.
6. Financial Advisor after getting IT knowledge one can advise and guide others in investing the money in various investment schemes.
7. It is possible to become a successful Animator using one’s own creation and innovation.
8. Perhaps one of the trendiest and most fun jobs in the sector, a games developer.
9. As a career opportunity, to become an Audio / Video Editor one should be good in tools such as Kdenlive, Audacity.

Question 22.
Write down the recent trends in IT.

1. Green Computing is the study and practice of environmentally sustainable computing or IT.
2. The goals of green computing are similar to green chemistry.
3. Green computing is important for all classes of systems, ranging from handheld systems to large-scale data centers.
4. The full form of IoT is the Internet of Things.
5. The Internet of Things is the network of physical devices, vehicles, home appliances, and other items embedded with electronics, software, sensors, actuators, and connectivity.
6. Cloud Computing is the delivery of computing services over the internet.
7. Data Analytics is the process of examining data sets in order to draw conclusions about the information.
8. Data Analytics technologies and techniques are widely used in commercial industries to enable organizations to make more informed business decisions.
9. Artificial Intelligence is intelligence demonstrated by machines, in contrast to the natural intelligence displayed by humans and other animals.
10. Computer science defines Artificial Intelligence research as the study of “intelligent agents”.
11. Machine Learning is the scientific study of algorithms and statistical models that computer systems use to effectively perform a specific task.
12. Big Data refers to data sets that are too large or complex for traditional data-processing application software.
13. Blockchain is a growing list of records, called blocks, which are linked using cryptography.

## Maharashtra Board Class 11 Physics Important Questions Chapter 9 Optics

Balbharti Maharashtra State Board 11th Physics Important Questions Chapter 9 Optics Important Questions and Answers.

## Maharashtra State Board 11th Physics Important Questions Chapter 9 Optics

Question 1.
Express the speed of EM waves in terms of permittivity and permeability of the medium.
In a material medium, the speed of EM waves is given by, c = $$\sqrt{\frac {1}{εµ}}$$
Where, ε = Permittivity and µ = permeability.
These constants depend on the electric and magnetic properties of the medium.

Question 2.
How can one classify commonly observed phenomena of light on the basis of nature of light?
Commonly observed phenomena concerning light can be broadly split into three categories:

1. Ray optics or geometrical optics: Ray optics can be used for understanding phenomena like reflection, refraction, double refraction, total internal reflection, etc.
2. Wave optics or physical optics: Wave optics explains the phenomena of light such as, interference, diffraction, polarisation, Doppler effect etc.
3. Particle nature of light: Particle nature of light can be used to explain phenomena like photoelectric effect, emission of spectral lines, Compton effect etc.

Question 3.
State the fundamental laws on which ray optics is based.
Ray optics is based on the following fundamental laws:
i. Light travels in a straight line in a homogeneous and isotropic medium.

ii. Two or more rays can intersect at a point without affecting their paths beyond that point.

iii. Laws of reflection:
a. Reflected ray lies in the plane formed by incident ray and the normal drawn at the point of incidence and the two rays are on either side of the normal.
b. Angles of incidence and reflection are equal (i = r).

iv. Laws of refraction:
a. Refracted ray lies in the plane formed by incident ray and the normal drawn at the point of incidence; and the two rays are on either side of the normal.

b. Angle of incidence (90 and angle of refraction (62) are related by Snell’s law, given by,
n1 sin θ1 = n2 sin θ2
where, n1, n2 = refractive indices of medium 1 and medium 2 respectively.

Question 4.
Explain Cartesian sign conventions using a graph.
According to Cartesian sign conventions:
i. All distances are measured from the optical centre or pole.

ii. Figures should be drawn in such a way that the incident rays travel from left to right. Thus, a real object should be shown to the left and virtual object or image to the right of pole (or optical centre).

iii. X-axis can be conveniently chosen as the principal axis with origin at the pole.

iv. Distances to the left of the pole are negative and those to the right of the pole are positive.

v. Distances above the principal axis (X-axis) are positive while those below it are negative.

Question 5.
Define and represent in a neat diagram the following terms:
i. Diverging beam
ii. Converging beam
i. A diverging beam of light corresponds to rays of light coming from real point object.

ii. A converging beam corresponds to rays of light directed to a virtual point object or image.

Question 6.
Thickness of the glass of a spectacle is 2 mm and refractive index of its glass is 1.5. Calculate time taken by light to cross this thickness. Express your answer with most convenient prefix attached to the unit ‘second’.
Speed of light in vacuum, c = 3 × 108 m/s
Given that:
Refractive index, (nglass) = 1.5
Thickness of the glass = 2 mm
= 2 × 10sup>-3 m
∵ Re fractive index (nglass) = $$\frac{\text { speed of light in vacuum }(\mathrm{c})}{\text { speed of light in glass (v) }}$$
∵ v = $$\frac{\mathrm{c}}{\mathrm{n}_{\text {glass }}}=\frac{3 \times 10^{8}}{1.5}$$ = 2 × 108 m/s
As v = $$\frac {s}{t}$$
time taken (t) to cross the thickness (s),
t = $$\frac{\mathrm{s}}{\mathrm{v}}=\frac{2 \times 10^{-3}}{2 \times 10^{8}}$$ = 1 × 10-11 s
Most convenient unit to express this small time is nano second. (1 ns = 10-9 s)
∴ t = 0.01 × 10-9 s = 0.01 ns

Question 7.
Explain the properties of the image formed after reflection of light from a plane surface.

1. The image of an object kept in front of a plane reflecting surface is virtual and laterally inverted.
2. Image is of the same size as that of the object.
3. It is situated at the same distance as that of object but on the other side of the reflecting surface.

Question 8.
Explain the formula to find the number of images formed when an object is placed in between two plane mirrors inclined at an angle θ.

1. If an object is kept between two plane mirrors inclined at an angle θ, multiple images (N) are formed due to multiple reflections from both the mirrors.
2. The number of images can be calculated using formula n = $$\frac {360}{θ}$$
3. Exact number of images seen (N) depends upon the angle between the mirrors and position of the object.
4. When n is an even integer, for all positions of the object the number of images formed are N = n – 1.
5. When n is an odd integer:
a. For an object placed at the angle bisector of the mirrors: N = n- 1
b. For an object placed off the angle bisector of the mirrors: N = n
6. If n is not an integer, N = m, where m is integral part of n.

Question 9.
Define radius of curvature of a spherical mirror.
Radius of the sphere of which a mirror is a part is called as radius of curvature of the mirror.

Question 10.
What is the focal length of a spherical mirror? Give its relation with the radius of curvature.
i. For a concave mirror focal length is the distance at which parallel incident rays converge. For a convex mirror, it is the distance from where parallel rays appear to be diverging after reflection.

ii. In case of spherical mirrors, half of radius of curvature is focal length of the mirror,
f = $$\frac {R}{2}$$

Question 11.
Show with the help of a ray diagram that focal length of convex mirror is positive while that of concave mirror is negative.
i. According to sign conventions, the incident rays are drawn from left of the mirror to the right as shown in the ray diagrams below.

ii. As the rays incident on convex mirror appear to converge at a point on the positive side of the origin, the focal length of the convex mirror is positive.

iii. However, in case of concave mirror, the rays converge at a point on negative side of the origin, the focal length of the concave mirror is negative.

Question 12.
Give relation between focal length, object distance and image distance for a small spherical mirror.
For a point object or for a small finite object, the focal length of a small spherical mirror is related to object distance and image distance as,
$$\frac {1}{f}$$ = $$\frac {1}{v}$$ + $$\frac {1}{u}$$

Question 13.
What is lateral magnification? How does it vary in different types of spherical mirrors?
i. Ratio of linear size of image to that of the object, measured perpendicular to the principal axis, is defined as the lateral magnification.
∴ m = $$\frac {h_2}{h_1}$$ = $$\frac {v}{u}$$ (for spherical lenses)
m = –$$\frac {v}{u}$$ (for spherical mirrors)

ii. For any position of the object, a convex mirror always forms virtual, erect and diminished image. Thus, lateral magnification for convex lens is always m < 1.

iii. In the case of a concave mirror, it depends upon the position of the object.

Question 14.
Complete the following table for a concave mirror?

 Position of object Position of image Lateral magnification U = ∞ v = f m = 0 u > 2f ……………. m < 1 u = f V = ∞ ……………… …………… |v| > |u| m > 1 2f > u > f ……………… m > 1

 Position of object Position of image Lateral magnification U = ∞ v = f m = 0 u > 2f 2f > v > f m < 1 u = f V = ∞ m = ∞ u < f |v| > |u| m > 1 2f > u > f v > 2f m > 1

Question 15.
Explain with proper diagram why parabolic mirrors are preferred over spherical one.
i. Unlike spherical shape, every point on a parabola is equidistant from a straight line and a point.

ii. Consider given parabola having RS as directrix and F as the focus. Points A, B, C on it are equidistant from line RS and point F.

iii. Hence A’A = AF, B’B = BF, C’C = CF, and so on.

iv. If rays of equal optical path converge at a point, that point is the location of real image corresponding to that beam of rays.

v. From figure, the paths A”AA’, B”BB’. C”CC’, etc., are equal paths when mirror is neglected.

vi. If the parabola ABC is a mirror then by definition of parabola the respective optical paths,
A”AF = B”BF = C”CF

vii. Thus, F is the single point focus for entire beam of rays parallel to the axis and there is no spherical aberration.
Hence, parabolic mirrors are preferred over spherical one as there is no spherical aberration.

Question 16.
A small object is kept symmetrically between two plane mirrors inclined at 38°. This angle is now gradually increased to 41°, the object being symmetrical all the time. Determine the number of images visible during the process.
The object is kept symmetrically between two plane mirrors. This implies the object is placed at angle bisector.
Thus, for θ = 38°,
n = $$\frac {360}{38}$$ = 9.47
As it is not integral, N = 9 (the integral part of n)
∴ For going from 38° to 41°, the mirrors go through angles 39° and 40°. Number of images formed will remain 9 for all angles between 38° and 40°.
For angles > 40°, the n goes on decreasing and when θ = 41°,
n = $$\frac {360}{41}$$ = 8.78 i.e., N = 8

Question 17.
A thin pencil of length 20 cm is kept along the principal axis of a concave mirror of curvature 30 cm. Nearest end of the pencil is 20 cm from the pole of the mirror. What will be the size of image of the pencil?
For the pencil kept along the principal axis and the end of the pencil closest to pole is at 20 cm,
say, u1 = -20 cm
Flence, the other end of the stick is at distance, u2 = (u1 + 20) = -40 cm from pole of the mirror.
As R = -30 cm, F = $$\frac {R}{2}$$ = -15 cm

∴ v2 = -24 cm
Here, negative signs indicate that images are formed on the left of the mirror.

The length of the image formed is given by,
v = v2 – v1 = -24 – (-60) = 36 cm.

Question 18.
An object is placed at 15 cm from a convex mirror having radius of curvature 20 cm. Find the position and kind of image formed by it.
Given: u = – 15 cm,
f = $$\frac {R}{2}$$ = + $$\frac {20}{2}$$ = + 10cm
To find: Nature and position of image (v)
Formula: $$\frac {1}{v}$$ + $$\frac {1}{u}$$ = $$\frac {1}{f}$$
Calculation:
From formula,
∴ $$\frac {1}{v}$$ = $$\frac {1}{f}$$ – $$\frac {1}{u}$$
= $$\frac {1}{+10}$$ – $$\frac {1}{-15}$$ = $$\frac {1}{10}$$ + $$\frac {1}{15}$$
= $$\frac {2+3}{30}$$ = $$\frac {5}{30}$$ = $$\frac {1}{6}$$
∴ v = 6 cm

Question 19.
Prove that refractive index of a glass slab is given by the formula,
n = $$\frac {Real depth}{Apparent depth}$$
i. Consider a plane parallel slab of a transparent medium of refractive index n.

ii. A point object O at real depth R appears to be at I at apparent depth A, when seen from outside (air).

iii. Consider incident ray OA and OB as shown in figure.

iv. Assuming i and r to be very small, we can write,
tan r = $$\frac {x}{A}$$ ≈ sin r and tan i = $$\frac {x}{R}$$ ≈ sin i

v. According to Snell’s law, for a ray travelling from denser medium to rarer medium,
n = $$\frac{\sin \mathrm{r}}{\sin \mathrm{i}} \approx \frac{\left(\frac{\mathrm{x}}{\mathrm{A}}\right)}{\left(\frac{\mathrm{x}}{\mathrm{D}}\right)}=\frac{\mathrm{R}}{\mathrm{A}}=\frac{\text { Real depth }}{\text { Apparent depth }}$$

Question 20.
The depth of a pond is 10 m. What is the apparent depth for a person looking normally to the water surface? nwater = 4/3.
Given: Real depth of pond, dreal = 10 m,
nw = $$\frac {4}{3}$$
To find: Apparent depth
Formula: n = $$\frac {Realdepth}{Apparent depth}$$
Calculation: From formula,
∴ Apparent depth = $$\frac {Realdepth}{n}$$ = $$\frac {10}{(\frac{4}{3})}$$
= $$\frac {10×3}{4}$$ = 7.5 m

Question 21.
A crane flying 6 m above a still, clear water lake sees a fish underwater. For the crane, the fish appears to be 6 cm below the water surface. How much deep should the crane immerse its beak to pick that fish?
For the fish, how much above the water surface does the crane appear? Refractive index of water = 4/3.
For crane, apparent depth of fish = 6 cm,
Given that refractive index (nw) = $$\frac {4}{3}$$
nw = $$\frac {Realdepth}{Apparent depth}$$
∴ Apparent depth = $$\frac {4}{3}$$ × 6 = 8 cm
Similarly, for fish, real height of crane = 6 m and
$$\frac{\mathrm{n}_{\mathrm{air}}}{\mathrm{n}_{\mathrm{w}}}=\frac{1}{\mathrm{n}_{\mathrm{w}}}=\frac{\text { Real height }}{\text { Apparent height }}$$
$$\frac {3}{4}$$ = $$\frac {6}{Apparent height}$$
i.e., Apparent height = $$\frac {4×6}{3}$$ = 8 m

Question 22.
Write a short note on Periscope.
i. Instrument used to see the objects on the surface of a water body from inside of water is called periscope.
ii. It consists of two right angled prisms. The incident rays of light are reflected twice through these prisms.
iii. Total internal reflections occur inside these prisms and a clear view of the surface of water is obtained.

Question 23.
A ray of light passes from glass (ng = 1.52) to water (nw = 1.33). What is the critical angle of incidence?
Given: ng = 1.52, nw = 1.33
To find: Critical angle (ic)
formula: sin ic = $$\frac {n_2}{n_1}$$ = $$\frac {n_w}{n_g}$$
Calculation:
From formula,
ic = sin-1 ($$\frac {1.33}{1.52}$$) = sin-1 (0.875) = 61°2′

Question 24.
There is a tiny LED bulb at the center of the bottom of a cylindrical vessel of diameter 6 cm. Height of the vessel is 4 cm. The beaker is filled completely with an optically dense liquid. The bulb is visible from any inclined position but just visible if seen along the edge of the beaker. Determine refractive index of the liquid.

As the bulb is just visible from the edge, the angle of incidence formed by ray OP must be equal to critical angle.
∴ refractive index (n) = $$\frac {1}{sin i_c}$$
From Figure,
tan ic = $$\frac {PQ}{OQ}$$ = $$\frac {4}{3}$$
∴ sin ic = $$\frac {OQ}{OP}$$ = $$\frac {3}{5}$$
∴ nliquid = $$\frac {5}{3}$$

Question 25.
What are convex and concave lenses? For which condition, convex lens will have negative focal length?

1. A lens is said to be convex if it is thicker in the middle and narrowing towards the periphery. According to Cartesian sign convention, its focal length is positive.
2. Convex lens is visualized to be internal cross section of two spheres (or one sphere or a plane surface).
3. A lens is concave if it is thicker at periphery and narrows down towards centre and has negative focal length.
4. Concave lens is visualized to be external cross section of two spheres.
5. For lenses of material optically rarer than the medium in which those are kept, convex lenses will have negative focal length and they will diverge the incident rays.

Question 26.
Which lenses can be considered as thin lenses?
Lenses for which the maximum thickness is at least 50 times smaller than all the other distances are considered as thin lenses.

Question 27.
Give the expression for the focal length of combination of lenses when
i. Lenses are kept in contact with each other
ii. Two lenses kept at a distance d apart from each other.
i. For thin lenses kept in contact:
$$\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{f}_{1}}+\frac{1}{\mathrm{f}_{2}}+\frac{1}{\mathrm{f}_{3}}$$ + ………

ii. For two lenses kept distance d apart:
$$\frac{1}{f}=\frac{1}{f_{1}}+\frac{1}{f_{2}}-\frac{d}{f_{1} f_{2}}$$

Question 28.
An object is placed infront of a convex surface separating two media of refractive index 1.1 and 1.5. The radius of curvature is 40 cm. Where is the image formed when an object is placed at 220 cm from the refracting surface?
Solution:
Given: n1 = 1.1, n2 = 1.5, R = + 40 cm,
u = -220 cm
To find: Position of image (v)
Formula: $$\frac{n_{2}}{v}-\frac{n_{1}}{u}=\frac{\left(n_{2}-n_{1}\right)}{R}$$
Calculation: From formula,

Question 29.
A glass paper-weight (n = 1.5) of radius 3 cm has a tiny air bubble trapped inside it. Closest distance of the bubble from the surface is 2 cm. Where will it appear when seen from the other end (from where it is farthest)?
From figure, distance OR = 2 cm
∴ Distance OP = 4 cm

According to sign conventions,
OP = u = -4 cm and CP = R = -3 cm
For refraction at curved surface,

Question 30.
Double-convex lenses are to be manufactured from a glass of refractive index 1.55, with both faces of the same radius of curvature. What is the radius of curvature required if the focal length is to be 20 cm?
Given: n = 1.55, f = 20 cm,
R1 = R and R2 = – R
(By sign convention)
To Find: Radius of curvature (R)
Formula: $$\frac{1}{\mathrm{f}}=(\mathrm{n}-1)\left(\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right)$$
Calculation: From formula,
$$\frac {1}{20}$$ = (1.55 – 1) $$\left[\frac{1}{R}-\left(-\frac{1}{R}\right)\right]=0.55 \times \frac{2}{R}$$
∴ R = $$\frac {1.10}{1}$$ × 20 = 22 cm

Question 31.
A dense glass double convex lens (n = 2) designed to reduce spherical aberration has |R1| : |R2| = 1:5. If a point object is kept 15 cm in front of this lens, it produces its real image at 7.5 cm. Determine R1 and R2.
Given: |R1| : |R2| = 1 : 5, u = -15 cm,
v = +7.5 cm, n = 2
To Find: Radii of curvature of double convex lens (R1) and (R2)
Formula:
i. $$\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{v}}-\frac{1}{\mathrm{u}}$$
ii. $$\frac {1}{f}$$ = (n – 1) $$\left(\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right)$$
Calculation: From formula (i),
$$\frac{1}{f}=\frac{1}{7.5}-\frac{1}{(-15)}=\frac{1}{5}$$
∴ f = +5 cm
Substituting this value in formula (ii), we get,
$$\frac{1}{5}=(2-1)\left(\frac{1}{R_{1}}-\frac{1}{R_{2}}\right)$$
∴ $$\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}=\frac{1}{5}$$
By sign conventions,
$$\frac{1}{\mathrm{R}_{1}}-\frac{1}{\left(-\mathrm{R}_{2}\right)}=\frac{1}{5}$$ ………….. (1)
Also $$\frac{\left|R_{1}\right|}{\left|R_{2}\right|}=\frac{1}{5}$$
∴ |R2| = 5 |R1| …………… (2)
Substituting in equation (1),
∴ $$\frac{1}{R_{1}}-\frac{1}{\left(-5 R_{1}\right)}=\frac{1}{5}$$
∴ $$\frac {6}{5R_1}$$ = $$\frac {1}{5}$$
∴ R1 = 6 cm
Using in equation (2),
R2 = 5 × 6 = 30 cm

Question 32.
Why are prism preferred for dispersion over two parallel surfaces? Explain its construction in brief.
i. In case of two parallel surfaces, for dispersion to be easily detectable, they must be separated over a large distance.
ii. In order to have appreciable and observable dispersion, two parallel surfaces are not useful. In such case we use prisms, in which two refracting surfaces inclined at an angle.
iii. Commonly used prisms have three rectangular surfaces forming a triangle.
iv. Two of which take part in refraction at a time. The one, not involved in refraction is called base of the prism.
v. Any section of prism perpendicular to the base is called principal section of the prism. Commonly all the rays considered during refraction lie in this plane.

Question 33.
Draw neat labelled diagrams showing refraction of a monochromatic light and white light through a prism.

Question 34.
For a prism prove that i + e = A + δ where the symbols have their usual meanings.
i. Consider a principal section ABC of a prism of absolute refractive index n kept in air as shown in figure.

ii. Let A be the refracting angle of prism and surface BC be the base.

iii. A monochromatic ray PQ obliquely strikes first reflecting surface AB such that, angle of incidence ∠PQM at Q is i.

iv. After refraction at Q, the ray deviates towards the normal and strikes second refracting surface AC at R which is the point of emergence.

v. Angles of refraction at Q (∠NQR) and at R (∠QRN) are r1 and r2 respectively.

vi. After R. the ray deviates away from normal and finally emerges along RS making e as the angle of emergence.

vii. Emergent ray RS meets an extended incident ray QT at X if traced backward. In this case, ∠TXS gives the angle of deviation.

viii. From figure,
∠AQN = ∠ARN = 90°
A + ∠QNR = 180° ………. (1)
From ∆ QNR,
r1 + r2 + ∠QNR = 180° ………. (2)
∴ A = r1 + r2 ……… (3)

ix. Angle δ forms an exterior angle for ∆ XQR.
∴ ∠XQR + ∠XRQ = δ
∴ (i – r1) + (e – r2) = δ
∴ (i + e) – (r1 + r2) = δ
From equation (3),
δ = i + e – A
∴ i + .e = A + δ

Question 35.
Explain δ versus i curve for refraction of light through a prism.
i. Variation of angle of incidence i with angle of deviation δ is as shown in figure.

ii. It shows that, with increasing values of i, the angle of deviation δ decreases initially to a certain minimum (δm) value and then increases.

iii. The curve shown in the figure is not a symmetric parabola, but the slope in the part towards right is less.

iv. Except at δ = δm there are two values of i for any given δ. From principle of reversibility of light, we can conclude that if one of these values is i, the other must be e and vice versa. Thus at δ = δm, we have i = e.

Question 36.
Show that, at condition of minimum deviation, n = $$\frac{\sin \left(\frac{\mathbf{A}+\boldsymbol{\delta}_{\mathrm{m}}}{\mathbf{2}}\right)}{\sin \left(\frac{\mathbf{A}}{\mathbf{2}}\right)}$$

i. For every angle of deviation except angle of minimum deviation, there are two values of angle of incidence.

ii. However, at angle of minimum deviation there is only one corressponding angle of incidence.

iii. From principle of reversibility in path PQRS, the values of i and e are interchangeable for every δ. Thus, at minimum deviation, i = e.

iv. This implies the angles of refraction r1 and r2 are also equal. Also, A = r1 + r2
∴ A = 2 r i.e., r = $$\frac {A}{2}$$ ……. (1)

v. In case of minimum deviation, QR is parallel to base BC and the figure is symmetric.

vi. Using i + e = A + δ,
i + i = A + δm
∴ i = $$\frac {A+δ_m}{2}$$ …………….(2)

vii. According to Snell’s law,
n = $$\frac {sin i}{sin r}$$
Thus, using equations (1) and (2),
n = $$\frac{\sin \left(\frac{\mathrm{A}+\delta_{\mathrm{m}}}{2}\right)}{\sin \left(\frac{\mathrm{A}}{2}\right)}$$
This is the prism formula.

Question 37.
For grazing emergence of a ray in a prism, find out minimum possible values for angle of incidence (i) and angle of refraction (r1) for commonly used glass prism.

i. At the point of emergence in prism, the ray travels from a denser medium into rarer.
Thus, if r2 = sin-1 ($$\frac {1}{n}$$) is the critical angle, the angle of emergence e = 90°. This is called grazing emergence.

ii. Angle of prism A is constant for a given prism and A = r1 + r2. Hence the corresponding r1 and i will have their minimum possible values.

iii. For commonly used glass prisms,
n = 1.5 (r2)max = sin-1 ($$\frac {1}{n}$$) = sin-1 ($$\frac {1}{1.5}$$) = 41.49°

iv. If, prism is symmetric (equilateral),
A = 60°
∴ r1 = 60° – 41°49′ = 18°11′
∴ n = 1.5 = $$\frac{\sin \left(\mathrm{i}_{\min }\right)}{\sin \left(18^{\circ} 11^{\prime}\right)}$$
sin (imin) = 1.5 × sin (18°11′)
∴ iimin = 27°55′ ≅ 28°.

Question 38.
Derive the formula for angle of deviation for thin prisms.
OR
Show that in a thin prism, for small angles of incidence, angle of deviation is constant (independent of angle of incidence).
For thin prisms (refracting angle < sin 10°). sin θ ≈ θ
∴ Refractive index, n = $$\frac{\sin \mathrm{i}}{\sin \mathrm{r}_{1}} \approx \frac{\mathrm{i}}{\mathrm{r}_{1}}$$
Also n = $$\frac{\sin e}{\sin \mathrm{r}_{2}} \approx \frac{\mathrm{e}}{\mathrm{r}_{2}}$$
∴ i ≈ n r1 and e ≈ nr2

ii. Substituting this in, i + e = A + δ, we get,
i + e = n (r1 + r2) = nA = A + δ
∴ S = A(n – 1)
A and n are constant for a given prism. Thus, for a thin prism, for small angles of incidence, angle of deviation is constant (independent of angle of incidence).

Question 39.
Give the expression for mean deviation for a beam of white light.
For a beam of white light, yellow colour is practically chosen to be the mean colour for violet and red.
This gives mean deviation as,
δVR = $$\frac{\delta_{\mathrm{V}}+\delta_{\mathrm{R}}}{2}$$ ≈ δY = A(nY – 1)
Where, nY = refractive index for yellow colour.

Question 40.
A fine beam of white light is incident upon the longer side of a plane parallel glass slab of breadth 5 cm at angle of incidence 60°. Calculate lateral deviation of red and violet rays and lateral dispersion between them as they emerge from the opposite side. Refractive indices of the glass for red and violet are 1.51 and 1.53 respectively.
As shown in figure,
VM = LV = lateral deviation for violet colour,
RT = LR = lateral deviation for red colour,
∴ Lateral dispersion between these colours, LVR = LV – LR

∴ rR = sin-1 (0.5735) ≈ 35°
Similarly,
sin rV = $$\frac{\sin 60^{\circ}}{1.53}=\frac{\sqrt{3}}{2 \times 1.53}=\frac{1.732}{3.06}$$
= antilog {log (1.732) – log (3.06)}
= antilog {0.2385 – 0.4857}
= antilog 11.7528}
= 0.5659
∴ sin rV = 0.566
∴ rV = sin-1 (0.566) = 34°28′
∴ Angle of deviation for red colour
= i – rR = 60° – 35° = 25°
and that for violet colur = i – rV = 60° – 34°28′
= 25°32′
From figure, in ∆ANR,
AR = $$\frac{\mathrm{AN}}{\cos \mathrm{r}_{\mathrm{R}}}=\frac{5}{\cos \left(35^{\circ}\right)}=\frac{5}{0.8192}$$ = 6.104 cm
Similarly ∆ANV,
AV = $$\frac{\mathrm{AN}}{\cos \mathrm{r}_{\mathrm{V}}}=\frac{5}{\cos \left(34^{\circ} 28^{\prime}\right)}=\frac{5}{0.8244}$$ = 6.065 cm
∴ For red colour, LR = RT = AR [sin(i – rR)]
= AR [sin (25°)]
= 6.104 × 0.4226
= 2.58 cm
For violet colour, LV = VM
= AV [sin (i – rV)]
= AV × sin (25° 32′)
= 6.065 × 0.431
= 2.61 cm
∴ LVR = LV – LR = 2.61 – 2.58 = 0.03 cm
= 0.3 mm

Question 41.
For a glass (n = 1.5) prism having refracting angle 60°, determine the range of angle of incidence for which emergent ray is possible from the opposite surface and the corresponding angles of emergence. Also calculate the angle of incidence for which i = e. How much is the corresponding angle of minimum deviation?
For an equilateral prism of glass, the minimum angle of incidence for which the emergent ray just emerges is imin = 27° 55′. Corresponding angle of emergence is, emax = 90°.
From the principle of reversibility of light, imax = 90° and emin = 27°55′
Also, for equilateral glass prism at minimum deviation,

Also, from prism formula,
i + e = A + δ
At minimum deviation,
∴ i + i = 60 + 37°10′ = 97°10′
∴ i = 48°35′

Question 42.
For a dense flint glass prism of refracting angle 10°, obtain angular deviation for extreme colours and dispersive power of dense flint glass. (nred = 1.712, nviolet = 1.792)
Given: A = 10°, nR = 1.712, nV = 1.792
To find:
i. Angular deviation for extreme colours (δV and δR)
ii. Dispersive power of flint glass (ω)
Formulae:
i. δ = A(n – 1)
ii. ω = $$\frac{\delta_{\mathrm{V}}-\delta_{\mathrm{R}}}{\left(\frac{\delta_{\mathrm{V}}+\delta_{\mathrm{R}}}{2}\right)}$$

Question 43.
The refractive indices of the material of the prism for red and yellow colour are 1.620 and 1.635 respectively. Calculate the angular dispersion and dispersive power, if refracting angle is 8°.
Solution:
Given: nR = 1.620, nY = 1.635, A = 8°
To find:
i. Angular dispersion (δV – δR)
ii. Dispersive power (ω)
Formulae:
i. δv – δr = A(nV – nR)
ii. ω = $$\frac{\mathrm{n}_{\mathrm{V}}-\mathrm{n}_{\mathrm{R}}}{\mathrm{n}_{\mathrm{Y}}-1}$$
Calculation: Since, nY = $$\frac {n_V+n_R}{2}$$
∴ nV = 2nY – nR
nV = 2 × 1.635 – 1.620 = 3.27 – 1.620
∴ nV = 1.65
From formula (i),
δV – δR = 8(1.65 – 1.620)
= 8 × 0.03 = 0.24°
∴ δV – δR = 0.24°
From formula (ii),
ω = $$\frac{1.65-1.620}{1.635-1}=\frac{0.03}{0.635}$$ = 0.0472

Question 44.
What could be the possible reasons for the upward bending of the light ray during hot days?
Possible reasons for the upward bending at the road could be:
i. Angle of incidence at the road is glancing. At glancing incidence, the reflection coefficient is very large which causes reflection.
ii. Air almost in contact with the road is not steady. The non-uniform motion of the air bends the ray upwards and once it has bent upwards, it continues to do so.

Question 45.
State some properties of rainbow.

1. It is seen during rains and on the opposite side of the Sun.
2. It is seen only during mornings and evenings and not throughout the day.
3. In the commonly seen rainbow red arch is outside and violet is inside.
4. In the rarely occurring concentric secondary rainbow, violet arch is outside and red is inside.
5. It is in the form of arc of a circle.
6. Complete circle can be seen from a higher altitude, i.e. from an aeroplane.
7. Total internal reflection is not possible in this case.

Question 46.
Why is total internal reflection not possible during formation of a rainbow ?
i. For total internal reflection, the angle of incidence in the denser medium must be greater than critical angle for the given pair of media.

ii. The relative refractive index of air with the water drop is just less than 1 and hence the critical angle is almost equal to 90°.

iii. Angle of incidence i in air, at the water drop, can’t be greater than 90°.

iv. As a result, angle of refraction r in water will always be less than the critical angle.

v. The figures shown indicates that this angle r itself acts as an angle of incidence at any point for one or more internal reflections. But this does not indicate the total internal reflection.

Question 47.
Rainbow is seen only for a definite angle range with respect to the ground. Justify.
i. For clear visibility of rainbow, a beam must have enough intensity.

ii. The curve for angle of deviation and angle of incidence is almost parallel to X-axis near minimum deviation i.e., for majority of angles of incidence in this range, the angle of deviation is nearly the same and those rays form a beam of enough intensity.

iii. Rays beyond this range suffer wide angular dispersion and thus will not have enough intensity for visibility. Hence, the rainbow is seen only for a definite angle range with respect to the ground for which the intensity of the beam is enough for the visibility.

Question 48.
How is the range of angles for which rainbows can be observed calculated?
i. Angle of deviation for the final emergent ray, can be shown to be equal to δ = π + 2i – 4r for primary rainbow and δ = 2π + 2i – 6r for the secondary rainbow.
ii. Using these relations along with Snell’s law, sin i = n sin r, derivatives of angle of deviation (δ) is obtained.
iii. Second derivative of δ comes out to be negative, which shows that it is the minima condition.
iv. Equating first derivative to zero corresponding values of i and r are obtained. Thus, from the figures shown, the corresponding angles θR and θV at the horizontal are obtained. These angles give the visible angular position for the rainbow.

Question 49.
When can one see complete circle of a rainbow? Explain in detail.
i. Figure given below illustrates formation of primary and secondary rainbows with their common centre O. It is the point where the line joining the sun and the observer meets the Earth when extended.

ii. P is location of the observer. Different colours of rainbows are seen on arches of cones of respective angles.

iii. Smallest half angle refers to the cone of violet colour of primary rainbow, which is 41°.

iv. As the Sun rises, the relative position of common centre of the rainbows with respect to observer shifts down. Hence as the Sun comes up, smaller and smaller part of the rainbows will be seen. If the Sun is above 41°, violet arch of primary rainbow cannot be seen.

v. Beyond 53°, no rainbows will be visible. That is why rainbows are visible only during mornings and evenings and in the shape of a bow.

vi. However, if observer moves up (may be in an aeroplane), the line PO itself moves up making lower part of the arches visible. After a certain minimum elevation, entire circle for all the cones can be visible.

Question 50.
Define following terms:
i. Longitudinal chromatic aberration
ii. Circle of least confusion
iii. Transverse chromatic aberration
i. Longitudinal chromatic aberration:
Due to different refractive indices and angle of deviations, violet and red colours of a white light converge at different focal points, fV and fR. The distance between fV and fR is measured as the longitudinal chromatic aberration.

ii. Circle of least confusion:
In presence of aberration the image is not a single point but always a circle. At particular location on the screen, this circle has minimum diameter. This is called circle of least confusion.

iii. Transverse chromatic aberration:
Radius of the circle of least confusion is called the transverse chromatic aberration.

Question 51.
After Cataract operation, a person is recommended with concavo-convex spectacles of curvatures 10 cm and 50 cm. Crown glass of refractive indices 1.51 for red and 1.53 for violet colours is used for this. Calculate the lateral chromatic aberration occurring due to these glasses.
For a concavo-convex lens, with convex shape facing the object, both the radii of curvature are positive as shown in the figure.

= (1.53 – 1) × 0.08 = 0.0424
∴ fv = 23.58 cm
∴ Longitudinal (lateral) chromatic aberration
= fV – fR = 24.51 – 23.58 = 0.93 cm

Question 52.
Why do we need optical instruments for?
i. Due to the limitation for focusing the eye lens it is not possible to take an object closer than a certain distance. This distance is called least distance of distance vision D. For a normal, unaided human eye D = 25cm.
ii. If an object is brought closer than this, we cannot see it clearly.
iii. If an object is too small the corresponding visual angle from 25 cm is not enough to see it and if we bring it closer than that, its image on the retina is blurred.
iv. Also, the visual angle made by cosmic objects far away from us such as stars is too small to make out minor details and we cannot bring those closer.
v. In such cases we need optical instruments like microscope and telescopes to observe these things clearly.

Question 53.
A convex lens has focal length of 2.0 cm. Find its magnifying power if image is formed at DDV.
Given: f = 2 cm, v = D = 25 cm
To find: Magnifying power (M.P.)
Formula: M.P = 1 + $$\frac {D}{f}$$
Calculation:
From formula,
M.P = 1 + $$\frac {25}{2}$$
M.P. = 1 + 12.5 = 13.5

Question 54.
A magnifying glass of focal length 10 cm is used to read letters of thickness 0.5 mm held 8 cm away from the lens. Calculate the image size. How big will the letters appear? Can you read the letters if held 5 cm away from the lens? If yes, of what size would the letters appear? If no, why not?
Given that, f = +10 cm, u = -8 cm,
From thin lens formula,
$$\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{v}}-\frac{1}{\mathrm{u}}$$
∴ $$\frac{1}{10}=\frac{1}{\mathrm{v}}-\frac{1}{-8}$$
∴ v = 40 cm
Magnification of a lens is,
m = $$\frac {v}{u}$$ = $$\frac {Object size h-i}{Object size h-0}$$
∴ $$\frac {40}{8}$$ = $$\frac {h_1}{0.5}$$
∴ h1 = 2.5 cm
This implies the height of the image is 5 times that of the object.
Magnifying power,
M = $$\frac {D}{u}$$ = $$\frac {25}{8}$$ = 3.125
∴ Image will appear to be 3.125 times bigger,
i.e., 3.125 × 0.5 = 1.5625 cm
For u = -5 cm, v will be -10 cm
For an average human being to see clearly, the image must be at or beyond 25 cm. Thus it will not possible to read the letters if held 5 cm away from the lens.

Question 55.
A compound microscope has a magnification of 15. If the object subtends an angle of 0.5° to eye, what will be the angle subtended by the image at the eye?
Given: M.P = 15, α = 0.5°
To Find: Angle(β)
Formula: M.P = $$\frac {β}{α}$$
Calculation:
From formula,
β = M.P × α = 15 × 0.5 = 7.5°

Question 56.
A compound microscope has a magnifying power of 40. Assume that the final image is formed at DDV(25 cm). If the focal length of eyepiece 10 cm, calculate the magnification produced by objective.
M.P = 40, D = 25 cm, fe = 10 cm
To Find: Magnification (m0)
Formula: M.P = m0 × Me
Calculation:
From the formula,

Question 57.
The pocket microscope used by a student consists of eye lens of focal length 6.25 cm and objective of focal length 2 cm. At microscope length 15 cm, the final image appears biggest. Estimate distance of the object from the objective and magnifying power of the microscope.
Given: fe = 6.25 cm, f0 = 2 cm, L = 15 cm
As image appears biggest, Ve = -25 cm.
To find:
i. Distance of object from objective (u0)
ii. Magnifying power (M)
Formula:
i. $$\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{v}}-\frac{1}{\mathrm{u}}$$
ii. L = |v0| + |ue|
iii. M = $$\left(\frac{v_{o}}{u_{o}}\right)\left(\frac{D}{u_{e}}\right)$$
Calculation: For eyelens, using formula (i),

∴ ue = 5 cm
From formula (ii),
|v0| = L – |ue|
= 15 – 5 = 10 cm
Using formula (i) for objective,

Question 58.
Focal length of the objective of an astronomical telescope is 1 m. Under normal adjustment, length of the telescope is 1.05 m. Calculate focal length of the eyepiece and magnifying power under normal adjustment.
Given: f0 = 1 m, L = 1.05 m
To find:
i. Focal length of eyepiece (fe)
Magnifying power under normal adjustment (M)
Formula:
i. L = f0 + fe
ii. M = $$\frac {f_0}{f_e}$$
Calculation. From formula (i),
fe = L – f0 = 1.05 – 1 = 0.05 m
From formula (ii),
M = $$\frac {1}{0.05}$$ = 20

Question 59.
Magnifying power of an astronomical telescope is 12 and the image is formed at D.D.V. If the focal length of the objective is 90 cm, what is the focal length of the eyepiece?
Given: M.P = 12, v = D, f0 = 90 cm,
To find: Focal length of eye piece (fe)
Formula: M.P = $$\frac {f_0}{f_e}$$ (1 + $$\frac {f_e}{D}$$)
Calculation:
From formula.
12 = $$\frac {90}{f_e}$$ (1 + $$\frac {f_e}{25}$$)
∴ fe = 10.71 cm

Question 60.
Two convex lenses of an astronomical telescope have focal length 1.3 m and 0.05 m respectively. Find the magnifying power and the length of the telescope.
Given: f0 = 1.3 m, fe = 0.05 m
To find:
i. Magnifying power of telescope (M.P.)
ii. Length of telescope (L)
Formulae:
i. M.P = $$\frac {f_0}{f_e}$$
ii. L = f0 + fe
Calculation: From formula (i),
M.P = $$\frac {1.3}{0.05}$$ = 26
From formula (ii),
L = 1.3 + 0.05 = 1.35 m

Question 61.
What is the angle of deviation of reflected ray if ray of light is incident on a plane mirror at an incident angle θ?
Answer: When a ray of light is incident on a plane mirror at an angle θ, the reflected ray gets deviated by an angle of (π – 2θ).

Question 62.
Does nature of the image depend upon size of the mirror?
No, nature of the image is independent of size of the mirror.

Question 63.
If a convex mirror is held in air and then dipped in oil, then what will be the change in its focal length?
Focal length of spherical mirrors are independent of the medium.

Question 64.
When ray of light falls normally on a mirror, its angle of incidence is 90°. True or false? Justify your answer.
False, when light falls normally on a mirror, its angle of incidence is zero degree.

Question 65.
In one of the performances, a magician keeps a gold ring beneath a thick glass slab (µ = $$\frac {3}{2}$$) Then he keeps a flask filled with water (µ = $$\frac {4}{3}$$), over the slab. Now when spectators one by one observe from the open end of the flask, the ring disappears at a certain angle of viewing.
i. What could be the reason behind the disappearance?
ii. At what angle of viewing the ring vanishes?
i. The ring disappears due to total internal reflection of the light at water-air interface.

ii. aµw = $$\frac {4}{3}$$
sin ic = $$\frac {1}{µ}$$
∴ ic = sin-1 ($$\frac {1}{_aµ_w}$$) = sin-1 ($$\frac {3}{4}$$) = 48.6°
Hence, for angle of viewing for which angle of incidence of ring from water to air is greater that 48.6°, the ring will vanish.

Question 66.
Why dispersion of light is not observed in glass slab but it is observed in prism?
When a light passes from one medium to another, at one interface, it changes its speed. The glass slab and prism both have two glass-air interfaces. Hence, the light undergoes refraction twice in both the cases. When the two interfaces are parallel to each other, although the colours are separated at first interface, they all travel the same path after refracting from second interface. However, in prism, the two interfaces are not parallel. Therefore, the colours separated at first interface do not travel the same path after second refraction but emerge out at different wavelengths producing spectrum.

Question 67.
A prism manufacturer is planning to build a dispersive prism out of following materials with the refracting angles as given.
i. Glass (µ = 1.5), A = 60°
ii. Plastic (µ = 1.4), A = 90°
iii. Fluorite (µ = 1.45), A = 64°
If he desires to give the prism following relations of i and δ, then which of the above combinations can be used to construct the prism?

From the given values of i and δ, δm = 37°
From prism formula, µ = $$\frac{\sin \left(\frac{\mathrm{A}+\delta_{\mathrm{m}}}{2}\right)}{\sin \left(\frac{\mathrm{A}}{2}\right)}$$

i. For Glass (µ = 1.5), A = 60°;
µ = $$\frac{\sin \left(\frac{60^{\circ}+37^{\circ}}{2}\right)}{\sin \left(30^{\circ}\right)}$$
= 1.5
Hence, this combination can be used for fabricating the desired prism.

ii. For Plastic (µ = 1.4), A = 90°;
µ = $$\frac{\sin \left(\frac{90^{\circ}+37^{\circ}}{2}\right)}{\sin \left(45^{\circ}\right)}$$
= 1.26
As Ppiastic = 1-4, this combination cannot be used.

iii. For Fluorite (µ = 1.45), A = 64°
µ = $$\frac{\sin \left(\frac{64^{\circ}+37^{\circ}}{2}\right)}{\sin \left(32^{\circ}\right)}$$
= 1.45
Hence, this combination can also be used for fabrication of prism.

Question 68.
Find the refractive index of material of following prism if the ray of light incident at angle 45° suffers minimum deviation through the prism.

A = 60°
Also, ray of light suffers minimum deviation.
∴ 2i = A + δm
∴ δm = 2i – A = 90° – 60° = 30°
From prism formula,
µ = $$\frac{\sin \left(\frac{\mathrm{A}+\delta_{\mathrm{m}}}{2}\right)}{\sin \left(\frac{\mathrm{A}}{2}\right)}$$
= $$\frac{\sin \left(\frac{60^{\circ}+30^{\circ}}{2}\right)}{\sin \left(30^{\circ}\right)}$$
= √2
Hence, refractive index of material of prism is √2.

Multiple Choice Questions

Question 1.
Time taken by light to cross a glass slab of thickness 4 mm and refractive index 3 is
(A) 4 × 10-11 s
(B) 2 × 10-11 ns
(C) 16 × 10-11 s
(D) 8 × 10-10 s
(A) 4 × 10-11 s

Question 2.
If mirrors are inclined to each other at an angle of 90°, the total number of images seen for a symmetric position of an object will be
(A) 3
(B) 4
(C) 5
(D) 3 or 4
(A) 3

Question 3.
In case of a convex mirror, the image formed is
(A) always on opposite side, virtual, erect.
(B) always on the same side, virtual, erect.
(C) always on opposite side, real, inverted.
(D) dependent on object distance.
(A) always on opposite side, virtual, erect.

Question 4.
A glass slab is placed in the path of a beam of convergent light. The point of convergence of light
(A) moves towards the glass slab.
(B) moves away from the glass slab.
(C) remains at the same point.
(D) undergoes a lateral shift.
(A) moves towards the glass slab.

Question 5.
For a person seeing an object placed in optically rarer medium,
(A) apparent depth of the object is more than real depth
(B) apparent depth is smaller than the real depth.
(C) apparent depthe might be smaller or greater depending on the position of the person.
(D) nothing can be concluded about the depth of object from given data.
(A) apparent depth of the object is more than real depth

Question 6.
Light travels from a medium of refractive index µ1 to another of refractive index µ21 > µ2). For total internal reflection of light, which is NOT true?
(A) Light must travel from medium of refractive index µ1 to µ2.
(B) Angle of incidence must be greater than the critical angle.
(C) There is no refraction of light.
(D) Light must travel from the medium of refractive index µ2 to µ1.
(D) Light must travel from the medium of refractive index µ2 to µ1.

Question 7.
Optical fibre is based on which of the following phenomenon?
(A) Reflection.
(B) Refraction.
(C) Total internal reflection.
(D) Dispersion.
(C) Total internal reflection.

Question 8.
Commonly used glass have refractive index of 1.5. What is the critical angle for such glass?
(A) 49°
(B) 42°
(C) 45°
(D) 40°
(B) 42°

Question 9.
If the refractive index of water is 4/3 and that of glass slab is 5/3. Then the critical angle of incidence for which a light ray tending to go from glass to water is totally reflected, is
(A) sin-1 ($$\frac {3}{4}$$)
(B) sin-1 ($$\frac {3}{5}$$)
(C) sin-1 ($$\frac {2}{3}$$)
(D) sin-1 ($$\frac {4}{5}$$)
(D) sin-1 ($$\frac {4}{5}$$)

Question 10.
While deriving prism formula, which of the following condition is NOT satisfied?
(A) I = e
(B) r1 = r2
(C) r = $$\frac {A}{2}$$
(D) δm = i + e + r
(D) δm = i + e + r

Question 11.
If the critical angle for the material of a prism is C and the angle of the prism is A, then there will be no emergent ray when
(A) A < 2 C
(B) A = 2 C
(C) A > 2 C
(D) A < $$\frac {C}{2}$$
(C) A > 2 C

Question 12.
Chromatic aberrations is caused due to
(A) spherical shape of lens
(B) spherical shape of mirrors
(C) angle of deviation for violet light being more than that for red light.
(D) refractive index for violet light being less than that for red light
(C) angle of deviation for violet light being more than that for red light.

Question 13.
In normal adjustment, magnifying powser of a astronomical telescope is given by
(A) $$\frac {D}{f_0}$$ $$\frac {L}{f_e}$$
(B) $$\frac {L}{D}$$ $$\frac {f_e}{f_0}$$
(C) $$\frac {f_0}{f_e}$$
(D) $$\frac {f_e}{f_0}$$
(C) $$\frac {f_0}{f_e}$$

## Maharashtra Board Class 11 Chemistry Important Questions Chapter 6 Redox Reactions

Balbharti Maharashtra State Board 11th Chemistry Important Questions Chapter 6 Redox Reactions Important Questions and Answers.

## Maharashtra State Board 11th Chemistry Important Questions Chapter 6 Redox Reactions

Question 1.
What does the term ‘redox’ refer to?
Redox is an abbreviation used for the terms ‘oxidation and reduction’.

Question 2.
Give examples of naturally occurring redox reactions.

1. Respiration
2. Rusting
3. Combustion of fuel

Question 3.
Define: Oxidant/Oxidising agent.
A reagent/substance which itself undergoes reduction and causes oxidation of another species is called oxidant/oxidising agent.

Question 4.
Define: Reductant/Reducing agent
A reagent/substance which itself undergoes oxidation bringing about the reduction of another species is called reductant/reducing agent.

Question 5.
Explain redox reaction giving an example.
Oxidation and reduction reactions occur simultaneously. Therefore, oxidation-reduction reaction is also referred as redox reaction.

In the above reaction, HgCl2 is reduced to Hg2Cl2 and SnCl2 is oxidised to SnCl4. Hence, it is a redox reaction.

Question 6.
Explain redox reaction in terms of electron transfer.
i. Redox reaction can be described in terms of electron transfer as shown below:
2Mg(s) + O2(g) → Mg2+ + 2O2-
ii. Charge development suggests that each magnesium atom loses two electrons to form Mg2+ and each oxygen atom gains two electrons to form O2-. This can be represented as follows:

iii. When Mg is oxidised to MgO, the neutral Mg atom loses electrons to form Mg2+ in MgO while the elemental oxygen gains electrons and forms O2- in MgO.
iv. Each of the above steps represents a half reaction which involves electron transfer (loss or gain).
v. Sum of these two half reactions or the overall reaction is a redox reaction.

Question 7.
Justify the following reaction as redox reaction in terms of electron transfer.
Mg + F2 → MgF2
i. Redox reaction can be described in terms of electron transfer as shown below:
Mg(s) + F2(g) → Mg2+ + 2F
ii. Charge development suggests that magnesium atom loses two electrons to form Mg2+ and each fluorine atom gains one electron to form F. This can be represented as follows:

iii. When Mg is oxidised to MgF2, the neutral Mg atom loses electrons to form Mg2+ in MgF2 while the elemental fluorine gains electrons and forms Fin MgF2.
iv. Each of the above steps represents a half reaction which involves electron transfer (loss or gain).
v. Sum of these two half reactions or the overall reaction is a redox reaction.

Question 8.
Justify that the reaction 2Na(s) + H2(g) → 2NaH(s) is a redox reaction.
Redox reaction can be described as electron transfer as shown below:
2Na(s) + H2(g) → 2Na+ + 2H
ii. Charge development suggests that each sodium atom loses one electron to form Na+ and each hydrogen atom gains one electron to form H. This can be represented as follows:

iii. When Na is oxidised to NaH, the neutral Na atom loses one electron to form Na+ in NaH while the elemental hydrogen gains one electron and forms H in NaH.
iv. Each of the above steps represents a half reaction which involves electron transfer (loss or gain).
v. Sum of these two half reactions or the overall reaction is a redox reaction.

Question 9.
Define the terms oxidation and reduction in terms of electron transfer.
i. The half reaction involving loss of electrons is called oxidation reaction.

ii. The half reaction involving gain of electrons is called reduction reaction.

Question 10.
Define the terms oxidant and reductant in terms of electron transfer.

1. Oxidant: Oxidant or oxidising agent is an electron acceptor.
2. Reductant: Reductant or reducing agent is an electron donor.

Question 11.
Identify oxidising and reducing agents in the following reaction.
$$\mathrm{Fe}_{(s)}+\mathrm{Cu}_{(\mathrm{aq})}^{2+} \longrightarrow \mathrm{Fe}_{(\mathrm{aq})}^{2+}+\mathrm{Cu}_{(\mathrm{s})}$$
Fe(s) acts as a reducing agent as it donates electrons while $$\mathrm{Cu}_{(\mathrm{aq})}^{2+}$$ acts as an oxidising agent as it accepts electrons.

Question 12.
Define: Displacement reaction.
A reaction in which an ion (or an atom) in a compound is replaced by an ion (or an atom) of another element is called displacement reaction.
e.g. X + YZ → XZ + Y

Question 13.
Draw structure and assign oxidation number to each atom in:
i. Br3O8
ii. C3O2
i. Br3O8

ii. C3O2

Question 14.
Deduce the oxidation number of S in the following species:
i. SO2
ii. $$\mathrm{SO}_{4}^{2-}$$
i. SO2 is a neutral molecule.
∴ Sum of oxidation numbers of all atoms of SO2 = 0
∴ (Oxidation number of S) + 2 × (Oxidation number of O) = 0
∴ Oxidation number of S + 2 × (- 2) = 0
∴ Oxidation number of S in SO2 = 0 – (- 4)
∴ Oxidation number of S in SO2 = +4

ii. $$\mathrm{SO}_{4}^{2-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms of $$\mathrm{SO}_{4}^{2-}$$ = – 2
∴ (Oxidation number of S) + 4 × (Oxidation number of O) = – 2
∴ Oxidation number of S in $$\mathrm{SO}_{4}^{2-}$$ = – 2 – 4 × (-2) = – 2 + 8
∴ Oxidation number of S in $$\mathrm{SO}_{4}^{2-}$$ = +6

Question 15.
Assign oxidation number to each element in the following compounds or ions.
i. KMnO4
ii. K2Cr2O7
iii. Ca3(PO4)2
i. KMnO4
Oxidation number of K = +1
Oxidation number of O = -2
KMnO4 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ (Oxidation number of K) + (Oxidation number of Mn) + 4 × (Oxidation number of O) = 0
∴ (+1) + Oxidation number of Mn + 4 × (-2) = 0
∴ Oxidation number of Mn + 1 – 8 = 0
∴ Oxidation number of Mn – 7 = 0
∴ Oxidation number of Mn in KMnO4 = +7

ii. K2Cr2O7
Oxidation number of K = +1
Oxidation number of O = -2
K2Cr2O7 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ 2 × (Oxidation number of K) + 2 × (Oxidation number of Cr) + 7 × (Oxidation number of O) = 0
∴ 2 × (+1) + 2 × (Oxidation number of Cr) + 7 × (-2) = 0
∴ 2 × (Oxidation number of Cr) + 2 – 14 = 0
∴ 2 × (Oxidation number of Cr) – 12 = 0
∴ 2 × (Oxidation number of Cr) = +12
∴ Oxidation number of Cr = +12/2
∴ Oxidation number of Cr in K2Cr2O7 = +6

iii. Ca3(PO4)2
Oxidation number of Ca = +2 (∵ Ca is alkaline earth metal.)
Oxidation number of O = -2
Ca3(PO4)2 is a neutral molecule.
Sum of the oxidation numbers of all atoms = 0
∴ 3 × (Oxidation number of Ca) + 2 × (Oxidation number of P) + 8 × (Oxidation number of O) = 0
∴ 3 × (+2)+ 2 × (Oxidation number of P)+ 8 × (-2) = 0
∴ 2 × (Oxidation number of P) + 6 – 16 = 0
∴ 2 × (Oxidation number of P) – 10 = 0
∴ 2 × (Oxidation number of P) = +10
∴ Oxidation number of P = +10/2
∴ Oxidation number of P in Ca3(PO4)2 = +5

Question 16.
Assign oxidation number to the atoms other than O and H in the following species.
i. $$\mathrm{SO}_{3}^{2-}$$
ii. $$\mathrm{BrO}_{3}^{-}$$
iii. $$\mathrm{ClO}_{4}^{-}$$
iv. $$\mathrm{NH}_{4}^{+}$$
v. $$\mathrm{NO}_{3}^{-}$$
vi. $$\mathrm{NO}_{2}^{-}$$
vii. SO3
viii. N2O5
The oxidation number of O atom bonded to a more electropositive atom is -2 and that of H atom bonded to electronegative atom is +1. Sum of the oxidation numbers of all atoms in ionic species is equal to charge it carries and that for neutral molecule is zero. Using these values, the oxidation numbers of atoms of the other elements in a given polyatomic species are calculated as follows:
i. $$\mathrm{SO}_{3}^{2-}$$
(Oxidation number of S) + 3 × (Oxidation number of O) = – 2
∴ Oxidation number of S + 3 × (-2) = – 2
∴ Oxidation number of S – 6 = – 2
∴ Oxidation number of S = – 2 + 6
∴ Oxidation number of S in $$\mathrm{SO}_{3}^{2-}$$ = +4

ii. $$\mathrm{BrO}_{3}^{-}$$
(Oxidation number of Br) + 3 × (Oxidation number of O) = -1
∴ Oxidation number of Br + 3 × (-2) = – 1
∴ Oxidation number of Br – 6 = – 1
∴ Oxidation number of Br = – 1 + 6
Oxidation number of Br in $$\mathrm{BrO}_{3}^{-}$$ = +5

iii. $$\mathrm{ClO}_{4}^{-}$$
(Oxidation number of Cl) + 4 × (Oxidation number of O) = – 1
∴ Oxidation number of Cl + 4 × (-2) = – 1
∴ Oxidation number of Cl – 8 = – 1
∴ Oxidation number of Cl = – 1 + 8
∴ Oxidation number of Cl in $$\mathrm{ClO}_{4}^{-}$$ = +7

iv. $$\mathrm{NH}_{4}^{+}$$
(Oxidation number of N) + 4 × (Oxidation number of H) = + 1
∴ Oxidation number of N + 4 × (+1) = +1
∴ Oxidation number of N + 4 = + 1
∴ Oxidation number of N = + 1 – 4
∴ Oxidation number of N in $$\mathrm{NH}_{4}^{+}$$ = -3

v. $$\mathrm{NO}_{3}^{-}$$
(Oxidation number of N) + 3 × (Oxidation number of O) = – 1
∴ Oxidation number of N + 3 × (-2) = – 1
∴ Oxidation number of N – 6 = – 1
∴ Oxidation number of N = – 1 + 6
∴ Oxidation number of N in $$\mathrm{NO}_{3}^{-}$$ = +5

vi. $$\mathrm{NO}_{2}^{-}$$
(Oxidation number of N) + 2 × (Oxidation number of O) = – 1
∴ Oxidation number of N + 2 × (-2) = – 1
∴ Oxidation number of N – 4 = – 1
∴ Oxidation number of N = – 1 + 4
∴ Oxidation number of N in $$\mathrm{NO}_{2}^{-}$$ = +3

vii. SO3
(Oxidation number of S) + 3 × (Oxidation number of O) = 0
∴ Oxidation number of S + 3 × (-2) = 0
∴ Oxidation number of S – 6 = 0
∴ Oxidation number of S = 0 + 6
∴ Oxidation number of S in SO3 = +6

viii. N2O5
2 × (Oxidation number of N) + 5 × (Oxidation number of O) = 0
∴ 2 × (Oxidation number of N) + 5 × (-2) = 0
∴ 2 × (Oxidation number of N) – 10 = 0
∴ 2 × (Oxidation number of N) = 0 + 10
∴ Oxidation number of N = 10/2
∴ Oxidation number of N in N2O5 = +5

Question 17.
Find the oxidation numbers of the underlined species in the following compounds or ions.

i. P$$\mathrm{F}_{6}^{-}$$
Oxidation number of F = -1
P$$\mathrm{F}_{6}^{-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms = – 1
∴ (Oxidation number of P) + 6 × (Oxidation number of F) = – 1
∴ Oxidation number of P + 6 × (-1) = -1
∴ Oxidation number of P – 6 = – 1
Oxidation number of P in P$$\mathrm{F}_{6}^{-}$$ = +5

ii. NaIO3
Oxidation number of Na = +1
Oxidation number of O = -2
NaIO3 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
(Oxidation number of Na) + (Oxidation number of I) + 3 × (Oxidation number of O) = 0
(+1) + (Oxidation number of I) + 3 × (-2) = 0
Oxidation number of I + 1 – 6 = 0
Oxidation number of I in NaIO3 = +5

iii. NaHCO3
Oxidation number of Na = +1
Oxidation number of H = +1
Oxidation number of O = -2
NaHCO3 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ (Oxidation number of Na) + (Oxidation number of H) + (Oxidation number of C) + 3 × (Oxidation number of O) = 0
∴ (+1) + (+1) + (Oxidation number of C) + 3 × (-2) = 0
∴ Oxidation number of C + 2 – 6 = 0
∴ Oxidation number of C in NaHCO3 = +4

iv. ClF3
Oxidation number of F = -1
ClF3 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ (Oxidation number of Cl) + 3 × (Oxidation number of F) = 0
∴ Oxidation number of Cl + 3 × (-1) = 0
∴ Oxidation number of Cl in ClF3 = +3

v. Sb$$\mathrm{F}_{6}^{-}$$
Oxidation number of F = -1
Sb$$\mathrm{F}_{6}^{-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms = – 1
∴ (Oxidation number of Sb) + 6 × (Oxidation number of F) = – 1
∴ Oxidation number of Sb + 6 × (-1) = -1
∴ Oxidation number of Sb in Sb$$\mathrm{F}_{6}^{-}$$ = +5

vi. NaBH4
Oxidation number of Na =+1
Oxidation number of H = -1 (for Hydride)
NaBH4 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ (Oxidation number of Na) + (Oxidation number of B) + 4 × (Oxidation number of H) = 0
∴ (+1) + (Oxidation number of B) + 4 × (-1) = 0
∴ Oxidation number of B + 1 – 4 = 0
∴ Oxidation number of B in NaBH4 = +3

vii. H2PtCl6
Oxidation number of H = +1
Oxidation number of Cl = -1
H2PtCl6 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ 2 × (Oxidation number of H) + (Oxidation number of Pt) + 6 × (Oxidation number of Cl) = 0
∴ 2 × (+1) + (Oxidation number of Pt) + 6 × (-1) = 0
(Oxidation number of Pt) + 2 – 6 = 0
∴ Oxidation number of Pt in H2PtCl6 = +4

viii. H5P3O10
Oxidation number of H = +1
Oxidation number of O = -2
H5P3O10 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ 5 × (Oxidation number of H) + 3 × (Oxidation number of P) +10 × (Oxidation number of O) = 0
∴ 5 × (+1) + 3 × (Oxidation number of P) + 10 × (-2) = 0
∴ 3 × (Oxidation number of P) + 5 – 20 = 0
Oxidation number of P = +$$\frac {15}{3}$$
∴ Oxidation number of P in H5P3O10 = +5

ix. V2$$\mathrm{O}_{7}^{4-}$$
Oxidation number of O = -2
V2$$\mathrm{O}_{7}^{4-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms = – 4
∴ 2 × (Oxidation number of V) + 7 × (Oxidation number of O) = – 4
∴ 2 × (Oxidation number of V) + 7 × (-2) = – 4
∴ 2 × (Oxidation number of V) = – 4 + 14
∴ Oxidation number of V = +$$\frac {10}{2}$$
∴ Oxidation number of V in V2$$\mathrm{O}_{7}^{4-}$$ = +5

x. CuSO4
Oxidation number of Cu = +2
Oxidation number of O = -2
CuSO4 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ (Oxidation number of Cu) + (Oxidation number of S) + 4 × (Oxidation number of O) = 0
∴ (+2) + Oxidation number of S + 4 × (-2) = 0
∴ Oxidation number of S + 2 – 8 = 0
∴ Oxidation number of S in CuSO4 = +6

xi. Bi$$\mathrm{O}_{3}^{-}$$
Oxidation number of O = -2
Bi$$\mathrm{O}_{3}^{-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms = – 1
∴ (Oxidation number of Bi) + 3 × (Oxidation number of O) = – 1
∴ Oxidation number of Bi + 3 × (-2) = – 1
∴ Oxidation number of Bi = – 1 + 6
∴ Oxidation number of Bi in Bi$$\mathrm{O}_{3}^{-}$$ = +5

xii. CH3OH
Oxidation number of H = +1
Oxidation number of O = -2
CH3OH is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ (Oxidation number of C) + 4 × (Oxidation number of H) + (Oxidation number of O) = 0
∴ (Oxidation number of C) + 4 × (+1) + (-2) = 0
∴ Oxidation number of C + 2 = 0
∴ Oxidation number of C in CH3OH = -2

xiii. H2O2
Oxidation number of O = -1 (for peroxide)
H2O2 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ 2 × (Oxidation number of H) + 2 × (Oxidation number of O) = 0
∴ 2 × (Oxidation number of H) + 2 × (-1) = 0
∴ Oxidation number of H = +$$\frac {2}{2}$$
∴ Oxidation number of H in H2O2 = +1

xiv. C4H4$$\mathrm{O}_{6}^{2-}$$
Oxidation number of H = +1
Oxidation number of O = -2
C4H4$$\mathrm{O}_{6}^{2-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms = – 2
∴ 4 × (Oxidation number of C) + 4 × (Oxidation number of H) + 6 × (Oxidation number of O) = – 2
∴ 4 × (Oxidationnumber of C) + 4 × (+1) +6 × (-2) = -2
∴ 4 × (Oxidation number of C) + 4 – 12 = -2
∴ 4 × (Oxidation number of C) = – 2 + 8
∴ Oxidation number of C = +$$\frac {6}{4}$$
∴ Oxidation number of C in C4H4$$\mathrm{O}_{6}^{2-}$$ = +1.5

xv. H2As$$\mathrm{O}_{4}^{-}$$
Oxidation number of H = +1
Oxidation number of O = -2
H2As$$\mathrm{O}_{4}^{-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms = – 1
∴ 2 × (Oxidation number of H) + (Oxidation number of As) + 4 × (Oxidation number of O) = -1
∴ 2 × (+1) + Oxidation number of As + 4 × (-2) = – 1
∴ Oxidation number of As + 2 – 8 = – 1
∴ Oxidation number of As = – 1 + 6
∴ Oxidation number of As in H2As$$\mathrm{O}_{4}^{-}$$ = +5

xvi. Mn(OH)3
Oxidation number of O = -2
Oxidation number of H = +1
Mn(OH)3 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ (Oxidation number of Mn) + 3 × (Oxidation number of O) + 3 × (Oxidation number of H) = 0
∴ Oxidation number of Mn + 3 × (-2) + 3 × (+1) = 0
∴ Oxidation number of Mn – 6 + 3 = 0
∴ Oxidation number of Mn in Mn(OH)3 = +3

xvii. $$\mathrm{I}_{3}^{-}$$
$$\mathrm{I}_{3}^{-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms = – 1
∴ 3 × Oxidation number of I = – 1
∴ Oxidation number of I in $$\mathrm{I}_{3}^{-}$$ = –$$\frac {1}{3}$$

xviii. C2H5OH
Oxidation number of O = -2
Oxidation number of H = +1
C2H5OH is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ 2 × (Oxidation number of C) + 6 × (Oxidation number of H) + (Oxidation number of O) = 0
∴ 2 × (Oxidationnumberof C) + 6 × (+1) + (-2) = 0
∴ 2 × (Oxidation number of C) = – 4
∴ Oxidation number of C = –$$\frac {4}{2}$$
∴ Oxidation number of C in C2H5OH = -2

xix. Na2CO3
Oxidation number of Na = +1
Oxidation number of O = -2
Na2CO3 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ 2 × (Oxidation number of Na) + (Oxidation number of C) + 3 × (Oxidation number of O) = 0
∴ 2 × (+1) + (Oxidation number of C) + 3 × (-2) = 0
∴ Oxidation number of C + 2 – 6 = 0
∴ Oxidation number of C in Na2CO3 = +4

xx. I$\mathrm{O}_{4}^{-}$
Oxidation number of O = -2
I$$\mathrm{O}_{4}^{-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms = – 1
∴ (Oxidation number of I) + 4 × (Oxidation number of O) = – 1
∴ Oxidation number of I + 4 × (-2) = – 1
∴ Oxidation number of I = -1 +8
∴ Oxidation number of I in I$$\mathrm{O}_{4}^{-}$$ = +7

xxi. V$$\mathrm{O}_{4}^{3-}$$
Oxidation number of O = -2
V$$\mathrm{O}_{4}^{3-}$$ is an ionic species.
∴ Sum of the oxidation numbers of all atoms = – 3
∴ (Oxidation number of V) + 4 × (Oxidation number of O) = – 3
∴ Oxidation number of V + 4 × (-2) = – 3
∴ Oxidation number of V = -3 + 8
∴ Oxidation number of V in V$$\mathrm{O}_{4}^{3-}$$ = +5

xxii. Ni2O3
Oxidation number of O = -2
Ni2O3 is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ 2 × (Oxidation number of Ni) + 3 × (Oxidation number of O) = 0
∴ 2 × (Oxidation number of Ni) + 3 × (-2) = 0
∴ 2 × (Oxidation number of Ni) = +6
∴ Oxidation number of Ni = +$$\frac {6}{2}$$
∴ Oxidation number of Ni in Ni2O3 = +3

xxiii. K3[Fe(CN)6]
Oxidation number of K = +1
Oxidation number of CN group = -1
K3[Fe(CN)6] is a neutral molecule.
∴ Sum of the oxidation numbers of all atoms = 0
∴ 3 × (Oxidation number of K) + (Oxidation number of Fe) + 6 × (Oxidation number of CN group) = 0
∴ 3 × (+1) + Oxidation number of Fe + 6 × (-1) = O
∴ Oxidation number of Fe + 3 – 6 = 0
∴ Oxidation number of Fe in K3[Fe(CN)6] = +3

Question 18.
Define: Stock notation.
Representation in which oxidation number of an atom is denoted by Roman numeral in parentheses after the chemical symbol is called Stock notation. This name was given after the German scientist, Alfred Stock. e.g. Au1+Cl1- → Au(I)Cl

Question 19.
What is the use of Stock notation?
The Stock notation is used to specify the oxidation number of the metal.

Question 20.
How will you write Stock notations for the following compounds?
i. AuCl3
ii. SnCl4
iii. SnCl2
iv. MnO2
i. AuCl3: The charge on each element is $$\mathrm{Au}^{3+} \mathrm{Cl}_{3}^{1-}$$. Hence, the stock notation is Au(III)Cl3.
ii. SnCl4: The charge on each element is $$\mathrm{Sn}^{4+} \mathrm{Cl}_{4}^{1-}$$. Hence, the stock notation is Sn(IV)Cl4.
iii. SnCl2: The charge on each element is $$\mathrm{Sn}^{2+} \mathrm{Cl}_{2}^{1-}$$. Hence, the stock notation is Sn(II)Cl2.
iv. MnO2: The charge on each element is $$\mathrm{Mn}^{4+} \mathrm{O}_{2}^{2-}$$. Hence, the stock notation is Mn(IV)O2.

Question 21.
Write the formula for each of the following ionic compounds:
i. Nickel(III) oxide
ii. Tin(IV) chloride
iii. Bismuth(V) chloride
iv. Cobalt(III) chloride
vi. Chromium(II) chloride
i. Ni2O3
ii. SnCl4
iii. BiCl5
iv. CoCl3
v. PbO2
vi. CrCl2

Question 22.
Define the terms oxidation and reduction in terms of oxidation number.
i. Oxidation is an increase in the oxidation number of an element in a given substance.
e.g. Fe(s) → $$\mathrm{Fe}_{(\mathrm{aq})}^{2+}$$
ii. Reduction is a decrease in the oxidation number of an element in a given substance. e.g. $$\mathrm{Cu}_{(\mathrm{aq})}^{2+}$$ → Cu(s)

Question 23.
Define the terms oxidant and reductant in terms of oxidation number.

1. Oxidant: Oxidant or oxidising agent is a substance which increases the oxidation number of an element in a given substance, and itself undergoes decrease in oxidation number of a constituent element in it.
2. Reductant: Reductant or reducing agent is a substance that lowers the oxidation number of an element in a given substance, and itself undergoes an increase in the oxidation number of a constituent element in it.

Question 24.
Identify whether the following reaction is redox or NOT. State oxidant and reductant therein.

i. Write oxidation number of all the atoms of reactants and products.

ii. Identify the species that undergoes change in oxidation number.

iii. The oxidation number of As increases from +3 to +5 and that of Br decreases from +5 to -1. Because oxidation number of one species increases and that of the other decreases, the reaction is a redox reaction.
iv. The oxidation number of As increases by loss of electrons and therefore, As is a reducing agent and itself is oxidised. On the other hand, the oxidation number of Br decreases and therefore, Br is an oxidising agent and itself is reduced by gain of electrons.
Result:
a. The given reaction is a redox reaction.
b. Oxidant/oxidising agent: $$\mathrm{BrO}_{3}^{-}$$
c. Reductant/reducing agent: H3AsO3

Question 25.
For the reaction, $$\mathrm{SeO}_{3(\mathrm{aq})}^{2-}+\mathrm{Cl}_{2(\mathrm{~g})}+2 \mathrm{OH}_{(\mathrm{aq})}^{-} \longrightarrow \mathrm{SeO}_{4(\mathrm{aq})}^{2-}+2 \mathrm{Cl}_{(\mathrm{aq})}^{-}+\mathrm{H}_{2} \mathrm{O}_{(l)}$$, complete the following table.

 Oxidising agent ————– Reducing agent ————– Oxidised species ————– Reduced species ————–

 Oxidising agent Cl2(g) Reducing agent $$\mathrm{Se} \mathrm{O}_{3(\mathrm{aq})}^{2-}$$ Oxidised species $$\mathrm{Se} \mathrm{O}_{4(\mathrm{aq})}^{2-}$$ Reduced species $$2 \mathrm{Cl}_{(\mathrm{aq})}^{-}$$

Question 26.
Using oxidation number concept, identify the redox reactions, identify oxidizing and reducing agents in case of redox reactions.

i. H3PO4(aq) + 3KOH(aq) → K3PO4(aq) + 3H2O(l)
a. Write oxidation number of all the atoms of reactants and products

b. Since, the oxidation numbers of all the species remain same, this is NOT a redox reaction.

Result:
The given reaction is NOT a redox reaction.

ii. Zn(s) + 2HCl(aq) → ZnCl2((aq)) + H2(g)
a. Write oxidation number of all the atoms of reactants and products.

b. Identify the species that undergoes change in oxidation number.

c. The oxidation number of Zn increases from 0 to +2 and that of H decreases from +1 to 0. Because oxidation number of one species increases and that of other decreases, the reaction is redox reaction.
d. The oxidation number of Zn increases by loss of electrons and therefore, Zn is a reducing agent and itself is oxidized. On the other hand, the oxidation number of H decreases by gain of electrons and therefore, H is oxidising an agent and itself is reduced by gain of electrons.

Result:

1. The given reaction is a redox reaction.
2. Oxidant/oxidising agent: HCl
3. Reductant/reducing agent: Zn

iii.

c. The oxidation number of Fe increases from +2 to +3 and that of Br decreases from +5 to -1. Because oxidation number of one species increases and that of the other decreases, the reaction is a redox reaction.
d. The oxidation number of Fe increases by loss of electrons and therefore, Fe is a reducing agent and itself is oxidized. On the other hand, the oxidation number of Br decreases by gain of electrons and therefore, Br is an oxidising an agent and itself is reduced.

Result:

1. The given reaction is a redox reaction.
2. Oxidant/oxidising agent: $$\mathrm{BrO}_{3}^{-}$$
3. Reductant/reducing agent: Fe2+

iv. 2Zn(s) + O2(g) → 2ZnO(s)
a. Write oxidation number of all the atoms of reactants and products.

b. Identify the species that undergoes change in oxidation number.

c. The oxidation number of Zn increases from 0 to +2 and that of O decreases from 0 to -2. Because oxidation number of one species increases and that of the other decreases, the reaction is a redox reaction.
d. The oxidation number of Zn increases by loss of electrons and therefore, Zn is a reducing agent and itself is oxidized. On the other hand, the oxidation number of O decreases by gain of electrons and therefore, O is an oxidising agent and itself is reduced.

Result:

1. The given reaction is a redox reaction.
2. Oxidant/oxidising agent: O2
3. Reductant/reducing agent: Zn

v. $$\mathrm{Sn}_{(a q)}^{2+}+\mathrm{IO}_{4(2 q)}^{-} \longrightarrow \mathrm{Sn}_{(aq)}^{4+}+\mathrm{I}_{(a \mathrm{q})}^{-}$$
a. Write oxidation number of all the atoms of reactants and products.

b. Identify the species that undergoes change in oxidation number.

c. The oxidation number of Sn increases from +2 to +4 and that of I decreases from +7 to -1. Because oxidation number of one species increases and that of the other decreases, the reaction is a redox reaction.
d. The oxidation number of Sn increases by loss of electrons and therefore, Sn is a reducing agent and itself is oxidized. On the other hand, the oxidation number of I decreases by gain of electrons and therefore, I is an oxidising agent and itself is reduced.

Result:

1. The given reaction is a redox reaction.
2. Oxidant/oxidising agent: Sn2+
3. Reductant/reducing agent: $$\mathrm{IO}_{4}^{-}$$

Question 27.
Name two methods used to balance redox reactions.

1. Oxidation number method
2. Half reaction method or ion electrode method

Question 28.
Describe the steps involved in balancing redox reactions by the oxidation number method.
i. Step 1: Write the unbalanced equation for redox reaction. Balance the equation for all atoms in the reactions, except H and O. Identify the atoms which undergo change in oxidation number and by how much. Draw the bracket to connect atoms of the elements that changes the oxidation number.

ii. Step 2: Show an increase in oxidation number per atom of the oxidised species and hence, the net increase in oxidation number. Similarly, show a decrease in the oxidation number per atom of the reduced species and the net decrease in oxidation number. Determine the factors which will make the total increase and decrease equal. Insert the coefficients into the equation.

iii. Step 3: Balance oxygen atoms by adding H2O to the side containing less O atoms, one H2O is added for one O atom. Balance H atoms by adding H+ ions to the side having less H atoms.

iv. Step 4: If the reaction occurs in basic medium, then add OH ions equal to the number of H+ ions added in step 3, on both the sides of equation. The H+ and OH ions on same side of reactions are combined to give H2O molecules.

v. Step 5: Check the equation with respect to both, the number of atoms of each element and the charges. It is balanced.
Note: For acidic medium, step 4 is omitted.

Question 29.
Using the oxidation number method write the net ionic equation for the reaction of potassium permanganate, KMnO4, with ferrous sulphate, FeSO4.
$$\mathrm{MnO}_{4(\mathrm{aq})}^{-}+\mathrm{Fe}_{(\mathrm{aq})}^{2+} \longrightarrow \mathrm{Mn}_{(\mathrm{aq})}^{2+}+\mathrm{Fe}_{(\mathrm{aq})}^{3+}$$
Step 1: Write skeletal equation and balance the elements other than O and H.
$$\mathrm{MnO}_{4(\mathrm{aq})}^{-}+\mathrm{Fe}_{(\mathrm{aq})}^{2+} \longrightarrow \mathrm{Mn}_{(\mathrm{aq})}^{2+}+\mathrm{Fe}_{(\mathrm{aq})}^{3+}$$

Step 2: Assign oxidation number to Mn and Fe, and calculate the increase and decrease in the oxidation number and make them equal.

To make the net increase and dicrease equal, we must take 5 atoms of Fe2+
$$\mathrm{MnO}_{4(\mathrm{aq})}^{-}+5 \mathrm{Fe}_{(\mathrm{aq})}^{2+} \longrightarrow \mathrm{Mn}_{(\mathrm{aq})}^{2+}+5 \mathrm{Fe}_{(\mathrm{aq})}^{3+}$$

Step 3: Balance the ‘O’ atoms by adding 4H2O to the right-hand side.
$$\mathrm{MnO}_{4(\mathrm{aq})}^{-}+5 \mathrm{Fe}_{(\mathrm{aq})}^{2+} \longrightarrow \mathrm{Mn}_{(\mathrm{aq})}^{2+}+5 \mathrm{Fe}_{(\mathrm{aq})}^{3+}+4 \mathrm{H}_{2} \mathrm{O}_{(l)}$$

Step 4: The medium is acidic. To make the charges and hydrogen atoms on the two sides equal, add 8H+ on the left-hand side.
$$\mathrm{MnO}_{4(\mathrm{aq})}^{-}+5 \mathrm{Fe}_{(\mathrm{aq})}^{2+}+8 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow \mathrm{Mn}_{(\mathrm{aq})}^{2+}+5 \mathrm{Fe}_{(\mathrm{aq})}^{3+}+4 \mathrm{H}_{2} \mathrm{O}_{(l)}$$

Step 5: Check the two sides for balance of charges and atoms. The net ionic equation obtained in step 4 is the balanced equation.
Hence, balanced equation:
$$\mathrm{MnO}_{4(\mathrm{aq})}^{-}+5 \mathrm{Fe}_{(\mathrm{aq})}^{2+}+8 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow \mathrm{Mn}_{(\mathrm{aq})}^{2+}+5 \mathrm{Fe}_{(\mathrm{aq})}^{3+}+4 \mathrm{H}_{2} \mathrm{O}_{(l)}$$

Question 30.
Balance the following reaction by oxidation number method.
CuO + NH3 → Cu + N2 + H2O
Step 1: Write skeletal equation and balance the elements other than O and H.
CuO + 2NH3 → Cu + N2 + H2O
Step 2: Assign oxidation number to Cu and N. Calculate the increase and decrease in the oxidation number and make them equal.

To make the net increase and decrease equal, we must take 3 atoms of Cu and 2 atoms of N. (There are already 2 N atoms.)
3CuO + 2NH3 → 3Cu + N2 + H2O
Step 3: Balance ‘O’ atoms by adding 3H2O to the right-hand side.
3CuO + 2NH3 → 3Cu + N2 + 3H2O
Step 4: Charges are already balanced.
Step 5: Check two sides for balance of atoms and charges. The equation obtained in step 3 is balanced.
Hence, balanced equation: 3CuO + 2NH3 → 3Cu + N2 + 3H2O

Question 31.
Balance the following redox equation by oxidation number method. The reactions occur in acidic medium.

i. $$\mathrm{H}_{2} \mathrm{O}_{2(\mathrm{aq})}+\mathrm{Cr}_{2} \mathrm{O}_{7 \text { (aq) }}^{2-} \longrightarrow \mathrm{O}_{2(\mathrm{~g})}+\mathrm{Cr}_{(\mathrm{aq})}^{3+}$$
Step 1: Write skeletal equation and balance the elements other than O and H.
$$\mathrm{H}_{2} \mathrm{O}_{2(\mathrm{aq})}+\mathrm{Cr}_{2} \mathrm{O}_{7 \text { (aq) }}^{2-} \longrightarrow \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{Cr}_{(\mathrm{aq})}^{3+}$$

Step 2: Assign oxidation number to O and Cr. Calculate the increase and decrease in the oxidation number and make them equal.

Since there are two Cr atoms, the net decrease in oxidation number is 6. In order to make the net increase and decrease equal, we must take 6 atoms of O i.e., 3H2O2.
$$3 \mathrm{H}_{2} \mathrm{O}_{2(\mathrm{aq})}+\mathrm{Cr}_{2} \mathrm{O}_{7(\mathrm{aq})}^{2-} \longrightarrow 3 \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{Cr}_{(\mathrm{aq})}^{3+}$$

Step 3: Balance ‘O’ atoms by adding 7H2O to the right-hand side.
$$3 \mathrm{H}_{2} \mathrm{O}_{2(\mathrm{aq})}+\mathrm{Cr}_{2} \mathrm{O}_{7(\mathrm{aq})}^{2-} \longrightarrow 3 \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{Cr}_{(\mathrm{aq})}^{3+}+7 \mathrm{H}_{2} \mathrm{O}_{(l)}$$

Step 4: The medium is acidic. To make the charges and hydrogen atoms on the two sides equal, add 8H+ on the left-hand side.
$$3 \mathrm{H}_{2} \mathrm{O}_{2(\mathrm{aq})}+\mathrm{Cr}_{2} \mathrm{O}_{7(\mathrm{aq})}^{2-}+8 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow 3 \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{Cr}_{(\mathrm{aq})}^{3+}+7 \mathrm{H}_{2} \mathrm{O}_{(l)}$$

Step 5: Check two sides for balance of atoms and charges.
Hence, balanced equation:
$$3 \mathrm{H}_{2} \mathrm{O}_{2(\mathrm{aq})}+\mathrm{Cr}_{2} \mathrm{O}_{7(\mathrm{aq})}^{2-}+8 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow 3 \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{Cr}_{(\mathrm{aq})}^{3+}+7 \mathrm{H}_{2} \mathrm{O}_{(l)}$$

ii. $$\mathrm{Ag}_{(\mathrm{s})}+\mathrm{NO}_{3(\mathrm{q})}^{-} \longrightarrow \mathrm{Ag}_{(\mathrm{aq})}^{+}+\mathrm{NO}_{2(\mathrm{~g})}$$

Step 1: Write skeletal equation and balance the elements other than O and H.
$$\mathrm{Ag}_{(\mathrm{s})}+\mathrm{NO}_{3(\mathrm{q})}^{-} \longrightarrow \mathrm{Ag}_{(\mathrm{aq})}^{+}+\mathrm{NO}_{2(\mathrm{~g})}$$

Step 2: Assign oxidation number to Ag and N. Calculate the increase and decrease in the oxidation number and make them equal.

Because net increase is equal to net decrease, multiplying coefficients are not required.

Step 3: Balance ‘O’ atoms by adding H2O to the right-hand side.
$$\mathrm{Ag}_{(\mathrm{s})}+\mathrm{NO}_{3(\mathrm{aq})}^{-} \longrightarrow \mathrm{Ag}_{(\mathrm{aq})}^{+}+\mathrm{NO}_{2(\mathrm{~g})}+\mathrm{H}_{2} \mathrm{O}_{(l)}$$

Step 4: The medium is acidic. To make the charges and hydrogen atoms on the two sides equal, add 2H+ on the left-hand side.
$$\mathrm{Ag}_{(\mathrm{s})}+\mathrm{NO}_{3(\mathrm{aq})}^{-}+2 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow \mathrm{Ag}_{(\mathrm{aq})}^{+}+\mathrm{NO}_{2(\mathrm{~g})}+\mathrm{H}_{2} \mathrm{O}_{(l)}$$
Thus, the equation is balanced with respect to the atoms as well as charges.

Step 5: Check two sides for balance of atoms and charges.
Hence, balanced equation: $$\mathrm{Ag}_{(\mathrm{s})}+\mathrm{NO}_{3(\mathrm{aq})}^{-}+2 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow \mathrm{Ag}_{(\mathrm{aq})}^{+}+\mathrm{NO}_{2(\mathrm{~g})}+\mathrm{H}_{2} \mathrm{O}_{(l)}$$

iii. $$\mathrm{Sn}_{(\mathfrak{a q})}^{2+}+\mathrm{IO}_{4(\mathrm{aq})}^{-} \longrightarrow \mathrm{Sn}_{(\mathrm{aq})}^{4+}+\mathrm{I}_{(\mathrm{aq})}^{-}$$

Step 1: Write skeletal equation and balance the elements other than O and H.
$$\mathrm{Sn}_{(\mathfrak{a q})}^{2+}+\mathrm{IO}_{4(\mathrm{aq})}^{-} \longrightarrow \mathrm{Sn}_{(\mathrm{aq})}^{4+}+\mathrm{I}_{(\mathrm{aq})}^{-}$$

Step 2: Assign oxidation number to Sn and I. Calculate the increase and decrease in the oxidation number and make them equal.

To make the net increase and decrease equal, we must take 4 atoms of Sn.
$$4 \mathrm{Sn}_{(\mathrm{aq})}^{2+}+\mathrm{IO}_{4(\mathrm{aq})}^{-} \longrightarrow 4 \mathrm{Sn}_{(\mathrm{aq})}^{4+}+\mathrm{I}_{(\mathrm{aq})}^{-}$$

Step 3: Balance ‘O’ atoms by adding 4H2O to the right-hand side.
$$4 \mathrm{Sn}_{(\mathrm{aq})}^{2+}+\mathrm{IO}_{4(\mathrm{aq})}^{-} \longrightarrow 4 \mathrm{Sn}_{(\text {aq })}^{4+}+\mathrm{I}_{(\text {aq })}^{-}+4 \mathrm{H}_{2} \mathrm{O}_{(l)}$$

Step 4: The medium is acidic. To make the charges and hydrogen atoms on the two sides equal, add 8H+ on the left-hand side.
$$4 \mathrm{Sn}_{(\mathrm{aq})}^{2+}+\mathrm{IO}_{4(\mathrm{aq})}^{-}+8 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow 4 \mathrm{Sn}_{(\mathrm{aq})}^{4+}+\mathrm{I}_{(\mathrm{aq})}^{-}+4 \mathrm{H}_{2} \mathrm{O}_{(l)}$$

Step 5: Check two sides for balance of atoms and charges.
Hence, balanced equation: $$4 \mathrm{Sn}_{(\mathrm{aq})}^{2+}+\mathrm{IO}_{4(\mathrm{aq})}^{-}+8 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow 4 \mathrm{Sn}_{(\mathrm{aq})}^{4+}+\mathrm{I}_{(\mathrm{aq})}^{-}+4 \mathrm{H}_{2} \mathrm{O}_{(l)}$$

iv. $$\mathrm{MnO}_{4(\mathrm{aq})}^{-}+\mathrm{IO}_{3(\mathrm{aq})}^{-} \longrightarrow \mathrm{MnO}_{2(\mathrm{~s})}+\mathrm{IO}_{4(\mathrm{aq})}^{-}$$

Step 1: Write skeletal equation and balance the elements other than O and H.
$$\mathrm{MnO}_{4(\mathrm{aq})}^{-}+\mathrm{IO}_{3(\mathrm{aq})}^{-} \longrightarrow \mathrm{MnO}_{2(\mathrm{~s})}+\mathrm{IO}_{4(\mathrm{aq})}^{-}$$

Step 2: Assign oxidation number to Mn and I. Calculate the increase and decrease in the oxidation number and make them equal.

To make the net increase and decrease equal, we must take 2 atoms of Mn and 3 atoms of I.
$$2 \mathrm{MnO}_{4(a q)}^{-}+3 \mathrm{IO}_{3(\mathrm{aq})}^{-} \longrightarrow 2 \mathrm{MnO}_{2(\mathrm{~s})}+3 \mathrm{IO}_{4(\mathrm{aq})}^{-}$$

Step 3: Balance ‘O’ atoms by adding 1H2O to the right-hand side.
$$2 \mathrm{MnO}_{4(\mathrm{aq})}^{-}+3 \mathrm{IO}_{3(\mathrm{aq})}^{-} \longrightarrow 2 \mathrm{MnO}_{2(\mathrm{~s})}+3 \mathrm{IO}_{4(\mathrm{aq})}^{-}+\mathrm{H}_{2} \mathrm{O}_{(l)}$$

Step 4: The medium is acidic. To make the charges and hydrogen atoms on the two sides equal, add 2H on the left-hand side.
$$2 \mathrm{MnO}_{4(\mathrm{aq})}^{-}+3 \mathrm{IO}_{3(\mathrm{aq})}^{-}+2 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow 2 \mathrm{MnO}_{2(\mathrm{~s})}+3 \mathrm{IO}_{4(\mathrm{aq})}^{-}+\mathrm{H}_{2} \mathrm{O}_{(l)}$$

Step 5: Check two sides for balanced of atoms and charges.
Hence, balanced equation: $$2 \mathrm{MnO}_{4(\mathrm{aq})}^{-}+3 \mathrm{IO}_{3(\mathrm{aq})}^{-}+2 \mathrm{H}_{(\mathrm{aq})}^{+} \longrightarrow 2 \mathrm{MnO}_{2(\mathrm{~s})}+3 \mathrm{IO}_{4(\mathrm{aq})}^{-}+\mathrm{H}_{2} \mathrm{O}_{(l)}$$

Question 32.
Balance the following redox equation in basic medium by oxidation number method:

i. $$\mathrm{Zn}_{(\mathrm{s})}+\mathrm{NO}_{3(\mathrm{aq})}^{-} \longrightarrow \mathrm{NH}_{3(\mathrm{aq})}+\mathrm{Zn}(\mathrm{OH})_{6(\mathrm{aq})}^{2-}$$

Step 1: Write skeletal equation and balance the elements other than 0 and H.
$$\mathrm{Zn}_{(\mathrm{s})}+\mathrm{NO}_{3(\mathrm{aq})}^{-} \longrightarrow \mathrm{NH}_{3(\mathrm{aq})}+\mathrm{Zn}(\mathrm{OH})_{6(\mathrm{aq})}^{2-}$$

Step 2: Assign oxidation number to Zn and N. Calculate the increase and decrease in the oxidation number and make them equal.

To make the net increase and decrease equal, we must take 2 atoms of Zn.
$$2 \mathrm{Zn}_{(\mathrm{s})}+\mathrm{NO}_{3(\mathrm{aq})}^{-} \longrightarrow \mathrm{NH}_{3(\mathrm{aq})}+2 \mathrm{Zn}(\mathrm{OH})_{6(\mathrm{aq})}^{2-}$$

Step 3: Balance ‘O’ atoms by adding 9H2O to the left-hand side.
$$2 \mathrm{Zn}_{(\mathrm{s})}+\mathrm{NO}_{3(\mathrm{aq})}^{-}+9 \mathrm{H}_{2} \mathrm{O}_{(l)} \longrightarrow \mathrm{NH}_{3(\mathrm{aq})}+2 \mathrm{Zn}(\mathrm{OH})_{6(\mathrm{aq})}^{2-}$$

Step 4: The medium is basic. To make hydrogen atoms on the two sides equal, add 3H on the right-hand side.

Step 5: Check two sides for balance of atoms and charges.
Hence, balanced equation:

ii. $$\mathrm{MnCl}_{2(\mathrm{aq})}+\mathrm{HO}_{2(\mathrm{aq})}^{-} \longrightarrow \mathrm{Mn}(\mathrm{OH})_{3(\mathrm{~s})}+\mathrm{Cl}_{(\mathrm{aq})}^{-}$$

Step 1: Write skeletal equation and balance the elements other than O and H.
$$\mathrm{MnCl}_{2(\mathrm{aq})}+\mathrm{HO}_{2(\mathrm{aq})}^{-} \longrightarrow \mathrm{Mn}(\mathrm{OH})_{3(\mathrm{~s})}+\mathrm{Cl}_{(\mathrm{aq})}^{-}$$

Step 2: Assign oxidation number to Mn and O. Calculate the increase and decrease in the oxidation number and make them equal.

iii. Cu(OH)2(s) + N2H4(aq) → Cu(s) + N2(g)
Step 1: Write skeletal equation and balance the elements other that O and H.
Cu(OH)2(s) + N2H4(aq) → Cu(s) + N2(g)
Step 2: Assign oxidation number to Cu and N. Calculate the increase and decrease in the oxidation number and make them equal.

To make the net increase and decrease equal, we must take 2 atoms of Cu.
2Cu(OH)2(s) + N2H4(aq) → 2Cu(s) + N2(g)
Step 3: Balance ‘O’ atoms by adding 4H20 to the right-hand side.
2Cu(OH)2(s) + N2H4(aq) → 2Cu(s) + N2(g) + 4H2O(l)
Step 4: The equation is balanced for both atoms as well as charges.
Step 5: Check two sides for balance of atoms and charges.
Hence, balanced equation: 2Cu(OH)2(s) + N2H4(aq) → 2Cu(s) + N2(g) + 4H2O(l)

Question 33.
Describe the steps involved in balancing redox reactions by ion electron method (Half reaction method).
In this method two half equations are balanced separately and then added together to give balanced equation. Following steps are involved.

• Step 1: Write unbalanced equation for the redox reaction, assign oxidation number to all the atoms in the reactants and products. Divide the equation into two half equations. One half equation involves increase in oxidation number and another involves decrease in oxidation number (Write two half equations separately).
• Step 2: Balance the atoms except O and H in each half equation. Balance oxygen atom by adding H2O to the side with less O atoms.
• Step 3: Balance H atoms by adding H+ ions to the side having less H atoms.
• Step 4: Balance the charges by adding appropriate number of electrons to the right side of oxidation half equation and to the left of reduction half equation.
• Step 5: Multiply half equation by suitable factors to equalize the number of electrons in two half equations. Add two half equations and cancel the number of electrons on both sides of equation.
• Step 6: If the reaction occurs in basic medium then add OH ions, equal to number of H+ ions on both sides of equation. The H+ and OH ions on same side of equation combine to give H2O molecules.
• Check that the equation is balanced in both, the atoms and the charges.

Question 34.
Balance the following unbalanced equation (in acidic medium) by ion electron method (half reaction method).
$$\mathrm{Mn}_{(\mathrm{aq})}^{2+}+\mathrm{ClO}_{3(\mathrm{qq})}^{-} \longrightarrow \mathrm{MnO}_{2(\mathrm{~s})}+\mathrm{ClO}_{2(\mathrm{aq})}$$
Step 1: Write imbalanced equation for the redox reaction. Assign oxidation number to all the atoms in reactants and products. Divide the equation into two half equations.

Step 2: Balance the atoms except O and H in each half equation. Balance half equations for O atoms by adding H2O to the side with less O atoms. Add 2H2O to left side of oxidation half equation and 1H2O to the right side of reduction half equation.

Step 3: Balance H atoms by adding H+ ions to the side with less H. Hence add 4H+ ions to the right side of oxidation half equation and 2H+ ions to the left side of reduction half equation.

Step 4: Now add 2 electrons to the right side of oxidation half equation and 1 electron to the left side of reduction half equation to balance the charges.

Step 5: Multiply reduction half equation by 2 to equalize number of electrons in two half equations. Then add two half equation.

$$\mathrm{Mn}_{(\mathrm{aq})}^{2+}+2 \mathrm{ClO}_{3(\mathrm{aq})}^{-} \longrightarrow \mathrm{MnO}_{2(\mathrm{~s})}+2 \mathrm{ClO}_{2(\mathrm{aq})}$$
The equation is balanced in terms of number of atoms and the charges.
Hence, balanced equation: $$\mathrm{Mn}_{(\mathrm{aq})}^{2+}+2 \mathrm{ClO}_{3(\mathrm{aq})}^{-} \longrightarrow \mathrm{MnO}_{2(\mathrm{~s})}+2 \mathrm{ClO}_{2(\mathrm{aq})}$$

Question 35.
Balance the following unbalanced equation by ion electron method (half reaction method).
$$\mathrm{H}_{2} \mathrm{O}_{2(\mathrm{aq})}+\mathrm{ClO}_{4(\mathrm{aq})}^{-} \longrightarrow \mathrm{ClO}_{2(\mathrm{aq})}^{-}+\mathrm{O}_{2(\mathrm{~g})}$$
Step 1: Write unbalanced equation for the redox reaction. Assign oxidation number to all the atoms in reactants and products. Divide the equation into two half equations.

Step 2: Balance the atoms except O and H in each half equation. Balance the half equation for O atoms by adding H2O to the side with less O atoms. Hence, add 2H2O to the right side of reduction half equation and none to the oxidation half equation

Step 3: Balance H atoms by adding H+ ions to the side with less H. Hence add 2H+ ions to the right side of oxidation half equation and 4H+ ions to the left side of reduction half equation.

Step 4: Add 2 electrons to the right side of oxidation half equation and 4 electrons to the left side of reduction half equation to balance the charges.

Step 5: Multiply oxidation half equation by 2 to equalize the number of electrons and then add two half equations.

Question 36.
Balance the following redox equations by ion-electron (half reaction method).

i. $$\mathrm{Cr}_{2} \mathrm{O}_{7(\mathrm{aq})}^{2-}+\mathrm{Fe}_{(\mathrm{aq})}^{2+} \longrightarrow \mathrm{Cr}_{(\mathrm{aq})}^{3+}+\mathrm{Fe}_{(\mathrm{aq})}^{3+}(\text { acidic })$$
Step 1: Write unbalanced equation for the redox reaction. Assign oxidation number to all the atoms in reactants and products. Divide the equation into two half equations.

Step 2: Balance the atoms except O and H in each half equation. Balance half equation for O atoms by adding 7H2O to the right side of reduction half equation.

Step 3: Balance H atoms by adding H+ ions to the side with less H. Hence, add 14H+ ions to the left side of reduction half equation.

Step 4: Now add 1 electron to the right side of oxidation half equation and 6 electrons to the left side of reduction half equation to balance the charges.

Step 5: Multiply oxidation half equation by 6 to equalize number of electrons in two half equations. Then add two half equation.

ii. $$\mathrm{SO}_{2(\mathrm{~g})}+\mathrm{Fe}_{(\mathrm{aq})}^{3+} \longrightarrow \mathrm{Fe}_{(\mathrm{aq})}^{2+}+\mathrm{SO}_{4(\mathrm{aq})}^{2-}(\text { acidic })$$
Step 1 : Write unbalanced equation for the redox reaction. Assign oxidation number to all the atoms in reactants and products in them. Divide the equation into two half equations.

Step 2: Balance the atoms except O and H in each half equation. Balance half equation for O atoms by adding 2H2O to the left side of oxidation half equation.

Step 3: Balance H atoms by adding H+ ions to the side with less H. Hence, add 4H+ ions to the right side of oxidation half equation.

Step 4: Now add 2 electrons to the right side of oxidation half equation and 1 electron to the left side of reduction half equation to balance the charges.

Step 5: Multiply reduction half equation by 2 to equalize number of electrons in two half equations. Then add two half equation.

iii. $$\mathrm{ClO}_{(\mathrm{aq})}^{-}+\mathrm{Cr}(\mathrm{OH})_{4(\mathrm{aq})}^{-} \longrightarrow \mathrm{CrO}_{4(\mathrm{aq})}^{2-}+\mathrm{Cl}_{(\mathrm{aq})}^{-} \text {(basic) }$$
Step 1: Write unbalanced equation for the redox reaction: Assign oxidation number to all the atoms in reactants and products. Divide the equation into two half equations.

Step 2: Balance the atoms except O and H in each half equation. Balance half equation for O atoms by adding 1H2O to the right side of reduction half equation.

Step 3: Balance H atoms by adding H+ ions to the side with less H. Hence, add 4H+ ions to the right side of oxidation half equation and 2H+ ions to the left side of reduction half equation.

Step 4: Now add 3 electrons to the right side of oxidation half equation and 2 electrons to the left side of reduction half equation to balance the charges.

Step 5: Multiply oxidation half equation by 2 and reduction half equation by 3 to equalize number of electrons in two half equations. Then add two half equation.

Step 6: The reaction takes place in basic medium. 20H ions, equal to the number of H+ ions (2H+ ions) are added on both sides of the equation.

iv. $$\mathrm{SeO}_{3(\mathrm{aq})}^{2-}+\mathrm{Cl}_{2(\mathrm{~g})} \longrightarrow \mathrm{SeO}_{4(a q)}^{2-}+\mathrm{Cl}_{(\mathrm{aq})}^{-} \text {(basic) }$$
Step 1: Write unbalanced equation for the redox reaction. Assign oxidation number to all the atoms in reactants and products in them. Divide the equation into two half equations.

Step 2: Balance the atoms except O and H in each half equation. Balance half equation for O atoms by adding H2O to the left side of oxidation half equation.

Step 3: Balance H atoms by adding H+ ions to the side with less H. Hence, add 2H+ ions to the right side of oxidation half equation.

Step 4: Now add 2 electrons to the right side of oxidation half equation and 2 electrons to the left side of reduction half equation to balance the charges.

Step 5: There is equal number of electrons in two half equations. Add two half equation.

Question 37.
Explain displacement reaction in terms of redox reaction by giving example.
i. Displacement reaction can be looked upon as redox reaction. Consider the following displacement reaction.

ii. Here, Zn gets oxidized to Zn2+ ion and Cu2+ ions get reduced to metallic Cu. A direct transfer of electron from zinc atom to cupric ions takes place in this case.

Question 38.
Explain construction of Daniel cell.

• The zinc and copper plates are connected by an electric wire through a switch and voltmeter.
• The solution in two containers are connected by salt bridge (U-shaped glass tube containing a gel of KCl or NH4NO3 in agar-agar).
• When switch is on, electrical circuit is complete as indicated by the deflection in the voltmeter.
• The circuit has two parts, one in the form of electrical wire which allows the flow of electrons and the other in the form of two solutions joined by salt bridge. In solution part of the circuit, the electric current is carried by movement of ions.

Question 39.
Explain working of Daniel cell.
i. When a circuit is complete, the zinc atoms on zinc plates spontaneously lose electrons which are picked up in the external circuit.
ii. The electrons flow from the zinc plate to copper plate through wire.
iii. Cu2+ ions in the second container receive these electrons through the copper plate and are reduced to copper atoms which get deposited on the copper plate.
iv. Here, zinc plate acts as anode (negative electrode) and the copper plate acts as cathode (positive electrode).

v. Thus, when two half reactions, namely, oxidation and reduction, are allowed to take place in separate containers and provision is made for completing the electrical circuit, electron transfer take place through the circuit.
vi. This results in flow of electric current in the circuit as indicated by deflection in voltmeter.
vii. Thus, in Daniel cell, electricity is generated by redox reaction.

Question 40.
Draw a neat and labelled diagram of Daniel cell.

Question 41.
Chalcopyrite (CuFeS2) is a common ore of copper. Since it has low concentration of copper, the ore is first concentrated through froth floatation process. The concentrated ore is then heated strongly with silicon dioxide (silica) and oxygen in a furnace. The product obtained, copper(I) sulphide, is further converted to copper (99.5% pure) with a final blast of air (O2) during which sulphur dioxide is released as a by-product.
i. Write a balanced reaction for the extraction of copper from copper(I) sulphide.
ii. Which species undergoes an increase in the oxidation state?
iii. Which species accepts electrons?
i. Cu2S + O2 → 2Cu + SO2
ii. Sulphur undergoes an increase in the oxidation state from -2 (in Cu2S) to +4 (in SO2).
iii. Copper accepts one electron and undergoes a decrease in the oxidation state from +1(in Cu2S) to 0 (in Cu). Oxygen accepts two electrons and undergoes a decrease in the oxidation state from 0 (in O2) to -2 (in SO2).

Question 42.
Consider the elements: Cs, Ne, I and F
i. Identify the element that exhibits only negative oxidation state.
ii. Identify the element that exhibits only positive oxidation state.
iii. Identify the element that exhibits both negative as well as positive oxidation state.
iv. Identify the element that exhibits neither the negative nor the positive oxidation state.
i. F: It is most electronegative. It shows only a negative oxidation state of -1.
ii. Cs: Alkali metals have only one electron in their valence shell and hence, exhibits only positive (+1) oxidation state.
iii. I: Because of the presence of 7 electrons in its valence shell, I shows negative oxidation state of -1 (to have stable noble gas configuration) and positive oxidation numbers of +1, +3, +5 and +7 because of the presence of d-orbitals.
iv. Ne: It is an inert gas and therefore, does not exhibit negative or positive oxidation state.

Multiple Choice Questions

1. Loss of electrons means ………….
(A) reduction
(B) oxidation
(C) precipitation
(D) complexometry
(B) oxidation

2. Reduction involves ……………
(A) gain of electrons
(C) increase in oxidation number
(D) loss of electron
(A) gain of electrons

3. Which of the following statement is INCORRECT?
(A) Oxidant is a substance which increases the oxidation number of other substance.
(B) Reductant is a substance which decreases the oxidation number of other substance.
(C) The oxidation number of oxidant decreases.
(D) In oxidation, there is decrease in oxidation number.
(D) In oxidation, there is decrease in oxidation number.

4. Which of the following is an example of oxidation process?

(D) $$\mathrm{Li}_{(\mathrm{s})} \longrightarrow \mathrm{Li}_{(\mathrm{g})}^{+}+\mathrm{e}^{-}$$

5. Which is the best description of the behaviour of chlorine in the reaction?
H2O + Cl2 → HOCl + HCl
(A) Neither oxidized not reduced
(B) Both oxidised and reduced
(C) Oxidised only
(D) Reduced only
(B) Both oxidised and reduced

6. In the reaction,
$$\begin{array}{r} 3 \mathrm{Br}_{2}+6 \mathrm{CO}_{3}^{2-}+3 \mathrm{H}_{2} \mathrm{O} \longrightarrow \ 5 \mathrm{Br}^{-}+\mathrm{BrO}_{3}^{-}+6 \mathrm{HCO}_{3}^{-} \end{array}$$ …………..
(A) Br2 is oxidised and carbonate is reduced
(B) bromine is reduced and water is oxidised
(C) bromine is neither reduced nor oxidised
(D) bromine is both reduced and oxidised
(D) bromine is both reduced and oxidised

7. A chemical reaction in which oxidation and reduction processes takes place simultaneously is known as ………… reaction.
(A) redox
(B) precipitation
(C) complexometric
(D) titration
(A) redox

8. Which of the following is a redox reaction?
(A) NaCl + KNO3 → NaNO3 + KCl
(B) CaC2O4 + 2HCl → CaCl2 + H2C2O4
(C) Mg(OH)2 + 2NH4Cl → MgCl2 + 2NH4OH
(D) Zn + 2AgCN → 2Ag + Zn(CN)2
(D) Zn + 2AgCN → 2Ag + Zn(CN)2

9. Oxidation number of metal ion is always …………..
(A) positive
(B) negative
(C) zero
(D) non zero
(A) positive

10. The oxidation number of oxygen in peroxide is …………..
(A) -2
(B) -1
(C) +1
(D) +2
(B) -1

11. The oxidation number of oxygen is …………. in oxygen difluoride.
(A) -2
(B) -1
(C) +2
(D) +1
(C) +2

12. Oxidation number of carbon in CH2F2 is ………….
(A) +1
(B) -1
(C) 0
(D) +2
(C) 0

13. In calcium hydride (CaH2), the oxidation number of hydrogen is ………….
(A) +1
(B) -1
(C) +2
(D) -2
(B) -1

14. The element with atomic number 9 can exhibit oxidation state of …………..
(A) +1
(B) +3
(C) -1
(D) +5
(C) -1

15. The highest and lowest oxidation states possible for Te (group 16) are ……………
(A) +6, -2
(B) +6, 0
(C) +4, -4
(D) +6, -6
(A) +6, -2

16. What is the oxidation state of S in Na2S2 ?
(A) +1
(B) -2
(C) -1
(D) 0
(C) -1

17. The oxidation state of S in S2O82- is ………….
(A) +2
(B) + 4
(C) +6
(D) + 7
(D) + 7

18. The oxidation state of phosphorus in Ba(H2PO2)2 is …………..
(A) +3
(B) +2
(C) +1
(D) -1
(C) +1

19. Amongst the following, identify the species having an atom with +6 oxidation state.
(A) $$\mathrm{MnO}_{4}^{-}$$
(B) $$\mathrm{Cr}(\mathrm{OH})_{3}^{6-}$$
(C) $$\mathrm{NiF}_{6}^{2-}$$
(D) CrO2Cl2
(D) CrO2Cl2

20. In which of the following compounds, the oxidation number of carbon is NOT zero?
(A) (CHCl)2
(B) HCHO
(C) CH3COOH
(D) CH2Cl2
(C) CH3COOH

21. The oxidation number of S in S8, S2F2 and H2S respectively are ………….
(A) 0, +1, -2
(B) +2, +1, -2
(C) 0, +1, +2
(D) +2, +1, -2
(A) 0, +1, -2

22. The coefficients x, y, and z in the following balanced equation
xZn + $$\mathrm{yNO}_{3}^{-}$$ + 10H+ → zZn2+ + $$\mathrm{NH}_{4}^{+}$$ + 3H2O are …………..
(A) 4, 1, 4
(B) 2, 2, 2
(C) 4, 2, 4
(D) 4, 4, 4
(A) 4, 1, 4

23. For the redox reaction:
$$\mathrm{MnO}_{4}{ }^{-}+\mathrm{C}_{2} \mathrm{O}_{4}^{2-}+\mathrm{H}^{+} \longrightarrow \mathrm{Mn}^{2+}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}$$
The CORRECT coefficients of the reactants in the balanced reaction are ……………

(A)

24. In the reaction
3CuO + 2NH3 → N2 + 3H2O + 3Cu
the change of NH3 to N2 involve ……………..
(A) loss of 6 electrons per mol of N2
(B) loss of 3 electrons per mol of N2
(C) gain of 6 electrons per mole N2
(D) gain of 3 electrons per mole N2
(A) loss of 6 electrons per mol of N2

25. When KMnO4 acts as an oxidising agent and ultimately forms $$\mathrm{MnO}_{4}^{2-}$$, MnO2, Mn2O3 and Mn2+, then the number of electrons transferred in each case is …………..
(A) 4, 3, 1, 5
(B) 1, 5, 3, 7
(C) 1, 3, 4, 5
(D) 3, 5, 7, 1
(C) 1, 3, 4, 5

26. In electrochemical cell, the magnitude and direction of the electrode potential depends on which of the following?
(A) Nature of metal and ions
(B) Concentration of ions
(C) Temperature
(D) All of these
(D) All of these

## Maharashtra Board Class 11 Biology Important Questions Chapter 12 Photosynthesis

Balbharti Maharashtra State Board 11th Biology Important Questions Chapter 12 Photosynthesis Important Questions and Answers.

## Maharashtra State Board 11th Biology Important Questions Chapter 12 Photosynthesis

Question 1.
What is the percentage of C02 in atmosphere?
Atmosphere contains only about 0.03 percent C02 by volume.

Question 2.
Define photosynthesis and give its reaction with the help of solar energy trapped by pigments like chlorophyll.
Photosynthesis is defined as synthesis of carbohydrates (glucose) from inorganic materials like CO2 and H20 with the help of solar energy trapped by pigments like chlorophyll.

Question 3.
Explain diagrammatically the ultrastructure of chloroplast.

1. The chloroplasts are discoid and lens shaped in higher plants. Chloroplast is bounded by a double membrane.
2. System of chlorophyll bearing a double-membrane sac is present inside the stroma. These are stacked one above the other to form grana.
3. Individual sacs in each granum is are known as thylakoid.
4. All the pigments chlorophylls, carotenes and xanthophylls are located in thylakoid membranes.
5. These pigments are fat soluble and are present in lipid part of membrane also they absorb light of specific spectrum in the visible regions.

Question 4.
Distinguish between grana and stroma.

 Grana Stroma 1. These are formed of stacks of thylakoids. It is the matrix of chloroplast. 2. Light reaction occurs in grana. Dark reaction occurs in stroma.

Question 5.
Describe a structure of a chlorophyll molecule.
1. Chemically chlorophyll molecule consists of two parts head of tetrapyrrole the porphyrin ring and a long hydrocarbon tail called phytol attached to the porphyrin group.
2. Both chlorophyll-a and chlorophyll-b are similar in their molecular structure, except that the methyl group (-CH3) in chlorophyll-a is replaced with an aldehyde group (-CHO) in chlorophyll-b.

Question 6.
What are Carotenoids?

1. Carotenoids are lipid compound present universally in almost all the higher plants and several microorganisms.
2. They are usually red, orange, yellow, brown, and are associated with chlorophyll. They are of two types – the carotenes and xanthophylls.
3. The carotenes (C40H56) are orange red and xanthophylls contain oxygen.
4. The light energy absorbed by the carotenoids is transferred to chlorophyll-a to be utilized in photosynthesis.
5. All photosynthetic plants have these pigments that absorb light between the red and blue region of the
spectrum.
6. Carotenoids found mainly in higher plants, absorb primarily in the violet to blue regions of the spectrum.
7. They not only absorb light energy and transfer it to chlorophyll but also protect the chlorophyll molecule from photo-oxidation.

Question 7.
Write a short note on nature of light.

1. Light is a form of energy.
2. It travels as stream of tiny particles called photons.
3. A photon contains a quantum of light.
4. Light has different wavelengths having different colors.
5. One can see electromagnetic radiation with wavelengths ranging from 390nm to 730nm. This part of the spectrum is called the Visible light.
6. It lies between wavelengths of ultraviolet and infra-red.

Question 8.
Draw neat and labelled diagram of absorption and action spectrum.
Absorption and action spectra

Question 9.
Write the chemical reaction given by Van Niel in case of bacteria that use H2S and C02 to synthesize carbohydrates. Write his postulate.
Chemical reaction given by Van Niel:
6C02 + 12H2S → C6H1206 + 6H20 + 12S ↓
Van Niel’s postulate:
Green plants use water in place of H2S and 02 is evolved in place of sulphur.

Question 10.
What was used by Ruben to confirm that the source of oxygen evolved in photosynthesis is water?
Ruben used heavy isotope of oxygen (1802) to confirm that the source of oxygen evolved in photosynthesis is water.

Question 11.
Explain Hill reaction.
In this experiment, Hill cultured isolated chloroplasts in a medium containing C02 free water, haemoglobin and ferric compound.

Question 12.
Give reason. Why photosynthesis is a redox reaction?
Photosynthesis is considered as a redox reaction as it involves both reduction and oxidation reactions.
Water is oxidized by the removal of H+ while C02 is reduced by the addition of H+.
The redox reactions of photosynthesis are necessary for the conversion of light energy into chemical energy.

Question 13.
Which are the two reactions involved in the process of photosynthesis.

1. The process of photosynthesis is an oxidation and reduction process in which water is oxidized (to release 02) and C02 is reduced to form sugar. It consists of two successive series of reactions.
2. The first reaction requires light and is called Light reaction.
3. Second reaction does not require light and is called Dark or Blackman reaction.
4. Of the two reactions, the former is a photochemical reaction, while the latter is a biochemical reaction.

Question 14.
What is light reaction?
1. The light reaction is a reaction in which solar energy is trapped by chlorophyll and stored in the form of chemical energy as ATP and in the form of reducing power as NADPH2.
2. Oxygen is evolved in the light reaction by splitting of water.

Question 15.
Define: Quantum energy
A certain minimum quantity of energy a photon must have to boost an electron is called quantum energy.

Question 16.
What is excited state?
A molecule that has absorbed a photon is in energy rich excited state. An excited state of an atom means that the valence electron has moved from its ground state orbital to high energy orbital.

Question 17.
What is ground state?
When the light source is turned off, the high energy electrons return rapidly to their normal low energy orbitals as the excited molecule reverts to its original stable condition, called the ground state.

Question 18.
Explain the structure of reaction centre.
Solar energy is trapped by chlorophyll and stored in the form of chemical energy as ATP and in the form of reducing power as NADPH2. Oxygen is evolved in the light reaction by splitting of water. The components of light reaction are as follows:

Reaction centre:

1. The light absorbing pigments present in thylakoid membranes are arranged in clusters of chlorophyll and accessory pigments.
2. P-680 and P-700 are the special type of chlorophyll molecules which form the reaction centres or photocentres.
3. Solar energy is harvested by accessory pigments and other chlorophyll molecule and is passed on to the reaction centre.
4. These (accessory pigments) are known as light harvesting or antenna molecule. Their function is to absorb light energy and transmit at a very high rate to the reaction centre where the photochemical reactions occur.

Question 19.
What are the two types of photosystems?
1. Photosystems:
a. Two kinds of photosystems are present in thylakoid membranes of chloroplasts.
b. Each has its own set of light harvesting chlorophyll and carotenoid molecules.
c. Chlorophyll and accessory pigments help to capture light energy over large area and pass it on to the photocenters.
d. Thus, a photon absorbed anywhere in the harvesting zone of P-680 center can pass its energy to the P680 molecule.
e. The cluster of pigments which transfer their energy to P-680 absorb at or below 680nm.
f. Together with P-680 they form Photosystem – II.
g. Likewise, P-700 forms Photosystem – I along with pigment molecule which absorbs light at or below 700 nm.

2. Photosystem II:
a. Photolysis of water and release of oxygen takes place in this system.
b. In this process, when PS-II absorbs light, electrons are released and chlorophyll molecule is oxidized.
c. Electrons emitted by P680 (PS-II) are ultimately trapped by P700 (PS -1).
d. Oxygen is the byproduct by the photosynthesizing plants.
e. Protons accumulate inside the thylakoid resulting in a Proton gradient.
f. When the protons diffuse across the thylakoid membrane into stroma against the H+ gradient, energy, is released.
g. This is used to produce ATP.

3. Photosystem 1:
a. Upon absorption of light quanta by PS-I (P700) reaction center emits energy rich electrons.
b. These flow down a chain of electron carriers to NADP along with the proton generated by splitting of water.
c. This result in the formation of NADPH.
d. Hydrogen attached to NADPH is used for reduction of C02 in dark reaction also called as reducing power of the cell.

Question 20.
The oxidized P-680 regains its electrons by the photolysis of water. Mention the reactions related to the same.
The oxidized P-680 regains its electrons by the photolysis of water as follows:

1. 4H2O → 4H+ + 40H
2. 4OH → 4(OH) + 4e
3. 4OH → 2H20 + 02
4. 4H2O → 2H2O + 02 ↑ + 4H+ 4e Overall reaction

Question 21.
Distinguish between Photosystem I and Photosystem II

1. The movement of ions across a selectively permeable membrane, down their electrochemical gradient is called chemiosmosis.
2. The movement of hydrogen ions across a membrane during cellular respiration in mitochondria and during photosynthesis in chloroplasts, leads to the generation of ATP.
3. These membranes are thylakoids and the protons accumulate in the lumen during photosynthesis.
4. An electrochemical concentration gradient forms when hydrogen ions (protons) diffuse from an area of higher proton concentration to an area of lower proton concentration.
5. This electrochemical concentration gradient of protons across a membrane can be utilized to make
ATP.
6. ATP synthase is the enzyme that makes ATP by chemiosmosis.
7. It allows protons to pass through the membrane using the kinetic energy to phosphorylate ADP making ATP.
8. Splitting of water molecule on the inner side of the membrane results in the accumulation of hydrogen ions within the lumen of thylakoids.
9. The enzyme, NADP reductase, is located in the stroma side of the membrane.
10. For reduction of NADP to NADPH2, protons are required along with electrons that come from ferredoxin.
11. Thus, within the chloroplast, the protons in the stroma decrease in number, while in the lumen, the number of protons increases.
12. This creates a proton gradient across the thylakoid membrane.
13. Energy,generated by the subsequent spontaneous movement of protons is used for the synthesis of ATP.

Question 22.
Draw neat and labelled diagram representing ATP synthesis through chemiosmosis.

Question 23.
What is photophosphorylation?
Formation of ATP in the chloroplasts in presence of light is called photophosphorylation, light

Question 24.
Mention the light reactions occurring in in granum.

1. 24H2O → 24OH + 24H+
2. 24OH → 240H + 24e
4. 18ADP + 18Pi → 18 ATP
5. 240H → 12H2O + 6O2

Question 25.
Write the dark reaction occurring in stroma.

Question 26.
Name the following:
1. Name the first compound formed during C3 pathway.
2. Carbon fixation occurs in?
1. 3-phosphoglyceric acid.
2. Stroma

Question 27.
Where does this reaction take place?
In stroma of a chloroplast.

Question 28.
Who discovered the Carbon fixation pathway? How was the pathway studied?

1. The path of carbon fixation in dark reaction through intermediate compounds leading to the formation of sugar and starch was discovered by Calvin, Benson and their co-workers discovered the carbon fixation pathway.
2. Path of carbon was studied with the help of radioactive tracer technique using Chlorella, a unicellular green alga and radioactive 14C02.
3. With the help of radioactive carbon, it becomes possible to trace the intermediate steps of fixation of 14C02.

Question 29.
When does photorespiration occur?
1. Photorespiration occurs under the conditions like high temperature, bright light, high oxygen and low C02 concentration. It is a wasteful process linked with C3-Cycle, where instead of fixation of C02, it is given out.
2. Photorespiration is a respiratory process in many higher plants by which they take up oxygen in the light and give outiearbon dioxide.

Question 30.
Diagrammatically explain the process of photorespiration.
Mechanism:

1. Photorespiration involves three organelles chloroplast, peroxisomes and mitochondria and occurs in a series of cyclic reactions which is also called PCO cycle. (Photosynthetic Carbon Cycle)
2. Enzyme Rubisco acts as oxygenase at higher concentration of O2 and photorespiration begins.
3. When RuBP reacts with 02 rather than C02 to form a 3-carbon compound (PGA) and 2-carbon compound phosphoglycolate.
4. Phosphoglycolate is then converted to glycolate which is shuttled out of the chloroplast into the peroxisomes.
5. In Peroxisomes, glycolate is converted into glyoxylate by enzyme glycolate oxidase.
6. Glyoxylate is further converted into amino acid glycine by transamination.
7. In mitochondria, two molecules of glycine are converted into serine (amino acid) and C02 is given out.
8. Thus, it loses 25% of photosynthetically fixed carbon.
9. Serine is transported back to peroxisomes and converted into glycerate.
10. It is shuttled back to chloroplast to undergo phosphorylation and utilized in formation of 3-PGA, which get utilized in C3 pathway.

Question 31.
Explain Hatch – Slack pathway.
1. M. D. Hatch and C. R. Slack while working on sugarcane found four carbon compounds (dicarboxylic acid) as the first stable product of photosynthesis.
2. It occurs in tropical and sub-tropical grasses and some dicotyledons.
3. The first product of this cycle is a 4-carbon compound oxaloacetic acid. Hence it is also called as C4 pathway and plants are called C4 plants.
Mechanism:

1. C02 taken from atmosphere is accepted by a 3-carbon compound, phosphoenolpyruvic acid in the chloroplasts of mesophyll cells, leading to the formation of 4-C compound, oxaloacetic acid with the help of enzyme phosphoenolpyruvate carboxylase.
2. It is converted to another 4-C compound, malic acid.
3. It is transported to the chloroplasts of bundle sheath cells.
4. Malic acid (4-C) is converted to pyruvic acid (3-C) with the release of C02 in the cytoplasm.
5. Thus, concentration of C02 increases in the bundle sheath cells.
6. Chloroplasts of these cells contain enzymes of Calvin cycle.
7. Because of high concentration of C02, RuBP carboxylase participates in Calvin cycle and not photorespiration.
8. Sugar formed in Calvin cycle is transported into the phloem.
9. Pyruvic acid generated in the bundle sheath cells re-enter mesophyll cells and regenerates
phosphoenolpyruvic acid by consuming one ATP.
10. Since this conversion results in the formation of AMP (not ADP), two ATP are required to regenerate ATP from AMP. Thus, C4 pathway needs 12 additional ATP.
11. The C3 pathway requires 18 ATP for the synthesis of one glucose molecule, whereas C4 pathway requires 30 ATP.
12. Thus, C4 plants are better photosynthesizers as compared to C3 plants as there is no photorespiration in these plants.

Question 32.
Draw a neat labelled diagram of Kranz anatomy of C4 plant.

Question 33.
Name the following:
1. Name the first product of C02 fixation in Hatch – Slack Pathway.
2. C4 plant leaf shows which type of anatomy?
3. Example of a C4 Plant
1. Oxaloacetic acid.
2. Kranz Anatomy
3. Maize, Sugarcane, Sorghum, etc.

Question 34.
Short note on Kranz Anatomy of a C4 plant.

1. Anatomy of leaves of C4 plants is different from leaves of C3 plants.
2. C4 plants show Kranz anatomy.
3. In the leaves of such plants, there is a bundle sheath around the vascular bundles.
4. The chloroplasts in the bundle – sheath cells are large and without or less developed grana, where as in the mesophyll cells the chloroplasts are small but with well-developed grana.

Question 35.
Short note on: Crassulacean Acid Metabolism.
Crassulacean Acid Metabolism (CAM).

1. It is one more alternative pathway of carbon fixation found in desert plants.
2. It was first reported in the family Crassulaceae, therefore called as CAM (Crassulacean Acid Metabolism).
3. In CAM plants, stomata are scotoactive i.e. active during night, hence initial C02 fixation occurs in night.
4. Thus, C4 pathway fix C02 at night and reduce C02 in day time via the C3 pathway by using NADPH formed during the day.
5. PEP caboxylase and Rubisco are present in the mesophyll cell (no Kranz anatomy).
6. Formation of malic acid during dark is called acidification (phase I).
7. Malate is stored in vacuoles during the night.
8. Malate releases C02 during the day for C3 pathway within the same cell is called deacidification (phase II).
9. Examples of CAM plants: Kalanchoe, Opuntia, Aloe etc.
10. The Chemical reactions of the carbon dioxide fixation and its assimilation are similar to that of C4 plants.

Question 36.
1. Draw a neat labelled diagram of CAM pathway.
2. In CAM plants, why does acid concentration increase during night?

2. In CAM plants, malic acid accumulates during night, which is formed from Oxaloacetic acid in presence of the enzyme malate dehydrogenase.

Question 37.
What are the external factors which affects photosynthesis?
External factors which affect photosynthesis are as follows:
1. Light:
a. It is an essential factor as it supplies the energy necessary for photosynthesis.
b. Quality and intensity of light affects the photosynthesis.
c. Highest rate of photosynthesis takes place in red light followed by blue light.
d. The rate of photosynthesis considerably decreases in plants which are growing under a forest canopy.
e. In most of the plants, photosynthesis is maximum in bright diffused sunlight.
f. Uninterrupted and continuous photosynthesis for a very long period of time may be sustained without any visible damage to the plant.

2. Carbon dioxide:
The main source of C02 in land plants is the atmosphere, which contains only 0.3% of the gas.
b. Under normal conditions of temperature and light, carbon dioxide acts as a limiting factor in photosynthesis.
c. Increase in concentration of CO2 increases the photosynthesis.
d. Increase in C02 to about 1% is advantageous to most of the plants.
e. Higher concentration of the gas has an inhibitory effect on photosynthesis.

3. Temperature:
a. Like all other physiological processes, photosynthesis also needs a suitable temperature.
b. The optimum temperature at which the photosynthesis is maximum is 25-30 °C. Except in plants like Opuntia, photosynthesis takes place at as high as 55 °C.
c. This is the maximum temperature. Minimum temperature is temperature at which photosynthesis process just starts.
d. In the presence of sufficient light and CO2, photosynthesis increases with the rise of temperature till it becomes maximum. After that there is a decrease or fall in the rate of the process.

4. Water:
a. Water is necessary for photosynthetic process.
b. An increase in water content of the leaf results in the corresponding increase in the rate of photosynthesis.
c. Thus, the limiting effect of water is not direct but indirect.
d. It is mainly due to the fact that it helps in maintaining the turgidity of the assimilatory cells and the proper hydration of their protoplasm.

Question 38.
What are the internal factors which affects photosynthesis?
Internal factors which affects photosynthesis are as follows:
1. Chlorophyll:
a. Though presence of chlorophyll is essential for photosynthesis but rate of photosynthesis is proportional to the quantity of chlorophyll present.
b. It is because of the fact that chlorophyll merely acts as a biocatalyst and hence a small quantity is quite enough to maintain the large bulk of the reacting substances.
2. Sugar:
The final product in the photosynthesis reaction is sugar and its accumulation in the cells slow down the process of photosynthesis.
3. Internal structures:
The thickness of cuticle and epidermis of the leaf, the size and distribution of intercellular spaces and the distribution of the stomata and the development of chlorenchyma and other tissues also affects the rate of photosynthesis.

Question 39.
State and explain the Blackman’s law of limiting factor.

1. The Blackman’s law of limiting factors states that when a process is conditioned as to its rapidity by a number of separate factors, the rate of the process is controlled by the pace of the “slowest factor”.
2. The slowest factor is that factor which is present in the lowest or minimum concentration in relation to others.
3. The law of limiting factor can be explained by taking two external factors such as carbon dioxide and light.
4. For example, a plant photosynthesizing at a fixed light intensity sufficient to utilize 10mg of C2 per hour only.
5. Photosynthetic rate goes on increasing when concentration of CO2 increases.
6. Further increase in CO2 concentration will not increase the rate of photosynthesis. In this case light becomes the limiting factor. Therefore, under such circumstances rate of photosynthesis can be increased only by increasing the light intensity.
7. This proves that the rate of photosynthesis responds to one factor alone at a time and there would be a sharp break in the curve and a plateau formed exactly at the point where another factor becomes limiting.
8. If any one of the other factors which is kept constant (e.g. Light) is increased, the photosynthetic rate increases again reaching the optimum where again another factor becomes limiting.

Question 40.
Give the significance of Photosynthesis.

1. Photosynthesis is anabolic process which uses inorganic substances and produces food for all life directly or indirectly.
2. This process transforms solar energy into chemical energy.
3. The released by product 02 is necessary not only for aerobic respiration in living organisms but also used in forming protective ozone layer around earth.
4. It also helps us in providing fossil fuels, coals, petroleum and natural gas.

Question 41.

Question 1.
1. Identify ‘x’, ‘y’ and ‘z’ in the given diagrammatic representation of cyclic photophosphorylation.
2. During which steps ATP molecules are formed?

1. ‘x’ is ferredoxin, ‘y’ is cytochrome-b6 and ‘z’ is plastocyanin.
2. During conversion of ferredoxin to cytochrome-b6 and from cytochrome-b6 to cytochrome-f ATP molecules are formed.

Question 42.
Quick Review

Cyclic and Non-cyclic photophosphorylation:

 Cyclic Non-cyclic Used Photons 1 ADP 1 Phosphate group Photons 1 ADP1 Phosphate group 1 H20 1 NADP+ Produced 2 ATP 1 ATP 2 NADPH + H+ $$\frac { 1 }{ 2 }$$O2 Accomplished Captured energy in the form of ATP Captured energy in the form of ATP and NADPH2 Transfers hydrogen (as NADPH) to the dark reactions

Calvin’s Cycle:

 Used (Reactants) Produced (Products) 6CO2 12 PGAL (2 become 1 glucose) 6 RUBP 18 Phosphates (return to light reactions) 18 ATP (from light reactions) 18 ADP (returns to light reactions) 12 NADPH (from light reactions) 12 NADP+ (return to light reactions)

Abbrevations

 ATP Adenosine triphosphate RuBisCO Ribulose bisphosphate carboxylase ADP Adenosine diphosphate PGA Phosphoglyceric acid Co-Q Co-enzyme quinone PGAL Phosphoglyceraldehyde FRS Ferredoxin Reducing Substance DHAP Dihydroxyacetone phosphate PC Plastocyanin NADP Nicotinamide adenine dinucleotide phosphate PQ Plastoquinone NADPH2 Nicotinamide adenine dinucleotide hydrogen phosphate RUBP Ribulose-1, 5-bisphosphate PEPA Phosphoenol pyruvic acid RUMP Ribulose monophosphate OAA Oxaloacetic acid

Question 43.
Exercise:

Question 1.
Why photosynthesis is known as redox reaction?

1. Photosynthesis is considered as a redox reaction as it involves both reduction and oxidation reactions.
2. Water is oxidized by the removal of H+ while C02 is reduced by the addition of H.
3. The redox reactions of photosynthesis are necessary for the conversion of light energy into chemical energy.

Question 2.
Sketch and label ‘Ultrastructure of Chloroplast’.

1. The chloroplasts are discoid and lens shaped in higher plants. Chloroplast is bounded by a double membrane.
2. System of chlorophyll bearing a double-membrane sac is present inside the stroma.
3. These are stacked one above the other to form grana.
4. Individual sacs in each granum is are known as thylakoid.
5. All the pigments chlorophylls, carotenes and xanthophylls are located in thylakoid membranes.
6. These pigments are fat soluble and are present in lipid part of membrane also they absorb light of specific spectrum in the visible regions.

Question 3.
Name the various photosynthetic pigments.

1. Chemically chlorophyll molecule consists of two parts head of tetrapyrrole the porphyrin ring and a long hydrocarbon tail called phytol attached to the porphyrin group.
2. Both chlorophyll-a and chlorophyll-b are similar in their molecular structure, except that the methyl group (-CH) in chlorophyll-a is replaced with an aldehyde group (-CHO) in chlorophyll-b.
3. Carotenoids are lipid compound present universally in almost all the higher plants and several microorganisms.
4. They are usually red, orange, yellow, brown, and are associated with chlorophyll. They are of two types – the carotenes and xanthophylls.
5. The carotenes (C40H5) are orange red and xanthophylls contain oxygen.
6. The light energy absorbed by the carotenoids is transferred to chlorophyll-a to be utilized in photosynthesis.
7. All photosynthetic plants have these pigments that absorb light between the red and blue region of the
spectrum.
8. Carotenoids found mainly in higher plants, absorb primarily in the violet to blue regions of the spectrum.
9. They not only absorb light energy and transfer it to chlorophyll but also protect the chlorophyll molecule from photo-oxidation. Xanthophylls (C40H56O2) are yellow pigments found in fruits and vegetables.

Question 4.
What is the main function of accessory pigment?
1. Accessory pigments are light absorbing molecules which are found in photosynthetic organisms.
2. They transfer the absorbed light to chlorophyll-a and thus increasing the photosynthetic rate.
3. In absence of accessory pigments less amount of light will be absorbed and also there would be no protection provided to chlorophyll molecule from photo-oxidation.

Question 5.
Explain the nature of light.

1. Light is a form of energy.
2. It travels as stream of tiny particles called photons.
3. A photon contains a quantum of light.
4. Light has different wavelengths having different colors.
5. One can see electromagnetic radiation with wavelengths ranging from 390nm to 730nm. This part of the spectrum is called the Visible light.
6. It lies between wavelengths of ultraviolet and infra-red.

Question 6.
Which instrument is used for studying the absorption spectrum of photosynthetic pigments?
In absorption spectrum, absorption of different wavelengths of light pigments can be measured by spectrophotometer.

Question 7.
Explain Hill’s reaction.
Robert Hill proved that the source of oxygen evolved during photosynthesis is water and not carbon dioxide. Hence, it is called Hill’s Reaction.

1. In this experiment, Hill cultured isolated chloroplasts in a medium containing C02 free water, haemoglobin and ferric compound.
2. Ferric salts and haemoglobin were added in the medium as hydrogen and oxygen acceptors respectively.
3. When the suspension was illuminated, he observed that haemoglobin turned into oxyhaemoglobin (red colour).
4. This confirmed that water must have oxidized releasing 02, that reacted with haemoglobin. Reduction of ferric compound was also indicated by change in colour.
5. The H2O molecule oxidized to evolve 02 as a by-product. Thus, Hill proved that the source of evolving 02 is H20 and not C02.
6. This process of splitting up of water molecules under the influence of light in the presence of chlorophyll is called Photolysis of water or Hill Reaction.

Question 8.
Describe photoexcitation of chlorophyll-a.

1. Chlorophyll-a is an essential photosynthetic pigment as it converts light energy into chemical energy and acts as a reaction centre.
2. Initially, it lies at ground state or singlet state but when it absorbs or receives photons (solar energy), it gets activated and goes in excited state or excited second singlet state.
3. In the excited state, chlorophyll-a emits an electron. The emitted electron is energy rich, i.e. has extra amount of energy.
4. Due to the loss of electron (e), chlorophyll-a becomes positively charged. This is the ionized state.
5. Chlorophyll-a molecule cannot remain in the ionized state for more than 10‘9 seconds. Hence the photo-chemical reaction or electron transfer occurs very fast.
6. The energy rich electron is then transferred through various electron acceptors and donors (carriers).
7. During the transfer, the electron emits energy which is utilized for the synthesis of ATP. This shows that light energy is converted into chemical energy in the form of ATP.

Question 9.
Write the wavelengths required for proper functioning of PS-I and PS-II respectively?
1. Together with P-680 they form Photosystem – II.
2. Likewise, P-700 forms Photosystem – I along with pigment molecule which absorbs light at or below 700 nm.

Question 10.
Differentiate between PS-IandPS-II.

1. The movement of ions across a selectively permeable membrane, down their electrochemical gradient is called chemiosmosis.
2. The movement of hydrogen ions across a membrane during cellular respiration in mitochondria and during photosynthesis in chloroplasts, leads to the generation of ATP.
3. These membranes are thylakoids and the protons accumulate in the lumen during photosynthesis.
4. An electrochemical concentration gradient forms when hydrogen ions (protons) diffuse from an area of higher proton concentration to an area of lower proton concentration.
5. This electrochemical concentration gradient of protons across a membrane can be utilized to make
ATP.
6. ATP synthase is the enzyme that makes ATP by chemiosmosis. .
7. It allows protons to pass through the membrane using the kinetic energy to phosphorylate ADP making ATP.
8. Splitting of water molecule on the inner side of the membrane results in the accumulation of hydrogen ions within the lumen of thylakoids.
9. The enzyme, NADP reductase, is located in the stroma side of the membrane.
10. For reduction of NADP to NADPH2, protons are required along with electrons that come from ferredoxin.
11. Thus, within the chloroplast, the protons in the stroma decrease in number, while in the lumen, the number of protons increases.
12. This creates a proton gradient across the thylakoid membrane.
13. Energy,generated by the subsequent spontaneous movement of protons is used for the synthesis of ATP.

Question 11.
Define photophosphorylation.
Formation of ATP in the chloroplasts in presence of light is called photophosphorylation, light

Question 12.
Give graphic representation of cyclic photophosphorylation.
Cyclic photophosphorylation:
a. Illumination of photosystem-I causes electrons to move continuously out of the reaction center of photosystem-I and back to it.
b. The cyclic electron-flow is accompanied by the photophosphorylation of ADP to yield ATP. This is termed as Cyclic photophosphorylation.
c. Since this process involves only pigment system I, photolysis of water and consequent evolution of oxygen does not take place.

Question 13.
Give graphic representation of noncyclic photophosphorylation.
Non-cyclic photophosphorylation:
a. It involves both photosystems- PS-I and PS-II.
b. In this case, electron transport chain starts with the release of electrons from PS-II.
c. In this chain high energy electrons released from PS-II do not return to PS-II but, after passing through an electron transport chain, reach PS-I, which in turn donates it to reduce NADP to NADPH.
d. The reduced NADP+ (NADPH) is utilized for the reduction of CO2 in the dark reaction.
e. Electron-deficient PS-II brings about oxidation of water-molecule. Due to this, protons, electrons and oxygen atom are released.
f. Electrons are taken up by PS-II itself to return to reduced state, protons are accepted by NADP+ whereas oxygen is released.
g. As in this process, high energy electrons released from PS-II do not return to PS-II and it is accompanied with ATP formation, this is called Non-cyclic photophosphorylation.

Question 14.
Write the link between light dependent and dark reactions.
Link between light-dependent and dark reactions:

1. The light reaction gives rise to two important products, a reducing agent NADPH2 and an energy-rich compound ATP. Both these are utilized in the dark phase of photosynthesis.
2. ATP and NADPH2 molecules function as vehicles for transfer of energy of sunlight into dark reaction leaving to carbon fixation. In this reaction C02 is reduced to carbohydrate.
3. During dark reaction, ATP and NADPH2 are transformed into ADP, iP and NADP which are transferred to the grana in which light reaction takes place.

Question 15.
Write the dark reaction occurring in stroma.

Question 16.
Explain how light and dark reactions of photosynthesis are interdependent.
Link between light-dependent and dark reactions:

1. The light reaction gives rise to two important products, a reducing agent NADPH2 and an energy-rich compound ATP. Both these are utilized in the dark phase of photosynthesis.
2. ATP and NADPH2 molecules function as vehicles for transfer of energy of sunlight into dark reaction leaving to carbon fixation. In this reaction C02 is reduced to carbohydrate.
3. During dark reaction, ATP and NADPH2 are transformed into ADP, iP and NADP which are transferred to the grana in which light reaction takes place.

Question 17.
Give schematic representation of Calvin Cycle.
1. The entire process of dark reaction was traced by Dr. Melvin Calvin along with his co-worker, Dr. Benson. Hence, the process is called as Calvin cycle or Calvin- Benson cycle. Since the first stable product formed is a 3-carbon compound, it is also called as C3 pathway and the plants are called C14 plants.
2. Calvin carried out experiments on unicellular green algae (Chlorella), using radioactive isotope of carbon, C14 as a tracer. It is also called synthesis phase or second phase of photosynthesis.

The cycle is divided into the following phases:
1. Carboxylation phase:
a. Carbon dioxide reduction starts with a five-carbon sugar ribulose-l,5-bisphosphate (RuBP). It is a 5- carbon sugar with two phosphate groups attached to it.
b. RuBP reacts with CO2 to produce an unstable 6 carbon intermediate in the presence of Rubisco.
c. It immediately splits into 3 carbon compounds called 3-phosphoglyceric acid.
d. RuBisCO is a large protein molecule and comprises 16% of the chloroplast proteins.

2. Glycolytic reversal:
a. 3-phosphoglyceric acid form 1,3-diphosphoglyceric acid by utilizing ATP molecule.
b. These are then reduced to glyceraldehyde-3-phosphate (3-PGA) by NADPH supplied by the light reactions of photosynthesis.
c. In order to keep Calvin cycle continuously running there must be sufficient number of RuBP and regular supply of ATP and NADPH.
d. Out of 12 molecules of 3-phosphoglyceraldehyde, two molecules are used for synthesis of one glucose molecule.

3. Regeneration of RuBP:
a. 10 molecules of 3-phosphoglyceraldehyde are used for the regeneration of 6 molecules of RuBP at the cost of 6 ATP.
b. Therefore, six turns of Calvin cycle are needed to get one molecule of glucose.

Question 18.
Describe Calvin cycle and its significance.
Significance:
1. Carboxylation: RuBisCO is the most abundant enzyme in the world. It is responsible for fixing carbon in the form of C02 into sugar. As a result of Carboxylation, the first stable product of carbon fixation i.e. 3- PGA is synthesized.
2. Reduction/Glycolytic reversal: NADPH2 donates electrons to 1, 3-Bisphoshoglycerate to form 3- phosphoglyceraldehyde molecules. During this process ADP and NADP are generated which are used in light reaction.
3. Regeneration of RuBP: Some 3-phosphoglyceraldehyde molecules are involved in production of glucose while others are recycled to regenerate the 5-carbon compound RuBP which used to accept new carbon molecules. Thus, regeneration of RuBP is required for Calvin cycle to run continuously.

Question 19.
How was the carbon fixation pathway studied?
1. Path of carbon was studied with the help of radioactive tracer technique using Chlorella, a unicellular green alga and radioactive 14C02.
2. With the help of radioactive carbon, it becomes possible to trace the intermediate steps of fixation of 14C02.

Question 20.
Describe photorespiration with the help of diagrammatic representation.
Mechanism:

1. Photorespiration involves three organelles chloroplast, peroxisomes and mitochondria and occurs in a series of cyclic reactions which is also called PCO cycle. (Photosynthetic Carbon Cycle)
2. Enzyme Rubisco acts as oxygenase at higher concentration of O2 and photorespiration begins.
3. When RuBP reacts with 02 rather than C02 to form a 3-carbon compound (PGA) and 2-carbon compound phosphoglycolate.
4. Phosphoglycolate is then converted to glycolate which is shuttled out of the chloroplast into the peroxisomes.
5. In Peroxisomes, glycolate is converted into glyoxylate by enzyme glycolate oxidase.
6. Glyoxylate is further converted into amino acid glycine by transamination.
7. In mitochondria, two molecules of glycine are converted into serine (amino acid) and C02 is given out.
8. Thus, it loses 25% of photosynthetically fixed carbon.
9. Serine is transported back to peroxisomes and converted into glycerate.
10. It is shuttled back to chloroplast to undergo phosphorylation and utilized information of 3-PGA, which get utilized in C3 pathway.

Question 21.
Give significance of C4 pathway.

1. C4 plants have special type of leaf anatomy called Kranz anatomy.
2. In C4 plants, C02 fixation occurs twice.
3. In these plants, chloroplasts of mesophyll cells contain enzyme PEP carboxylase which fixes atmospheric C02. Thus, first C02 fixation occurs in mesophyll cells.
4. Decarboxylation of malic acid in bundle sheath cells results in increase in C02 concentration.
5. Thus, RuBisCO acts as carboxylase and brings about carboxylation of RuBP.
6. Due to this oxygenation of RuBP and photorespiration is prevented.
7. Thus, despite of having less number of bundle sheath cells carrying out Calvin cycle, C4 plants are highly productive.

Question 22.
Who proposed C4 pathway?
1. M. D. Hatch and C. R. Slack while working on sugarcane found four carbon compounds (dicarboxylic acid) as the first stable product of photosynthesis.
2. It occurs in tropical and sub-tropical grasses and some dicotyledons.
3. The first product of this cycle is a 4-carbon compound oxaloacetic acid. Hence it is also called as C4 pathway and plants are called C4 plants.
Mechanism:

1. C02 taken from atmosphere is accepted by a 3-carbon compound, phosphoenolpyruvic acid in the chloroplasts of mesophyll cells, leading to the formation of 4-C compound, oxaloacetic acid with the help of enzyme phosphoenolpyruvate carboxylase.
2. It is converted to another 4-C compound, malic acid. It is transported to the chloroplasts of bundle sheath cells.
3. Malic acid (4-C) is converted to pyruvic acid (3-C) with the release of C02 in the cytoplasm.
4. Thus, concentration of C02 increases in the bundle sheath cells.
5. Chloroplasts of these cells contain enzymes of Calvin cycle.
6. Because of high concentration of C02, RuBP carboxylase participates in Calvin cycle and not photorespiration.
7. Sugar formed in Calvin cycle is transported into the phloem.
8. Pyruvic acid generated in the bundle sheath cells re-enter mesophyll cells and regenerates
phosphoenolpyruvic acid by consuming one ATP.
9. Since this conversion results in the formation of AMP (not ADP), two ATP are required to regenerate ATP from AMP. Thus, C4 pathway needs 12 additional ATP.
10. The C3 pathway requires 18 ATP for the synthesis of one glucose molecule, whereas C4 pathway requires 30 ATP.
11. Thus, C4 plants are better photosynthesizers as compared to C3 plants as there is no photorespiration in these plants.

Question 23.
Give schematic representation of HSK pathway.
1. M. D. Hatch and C. R. Slack while working on sugarcane found four-carbon compounds (dicarboxylic acid) as the first stable product of photosynthesis.
2. It occurs in tropical and sub-tropical grasses and some dicotyledons.
3. The first product of this cycle is a 4-carbon compound oxaloacetic acid. Hence it is also called as C4 pathway and plants are called C4 plants.

Mechanism:

1. C02 taken from atmosphere is accepted by a 3-carbon compound, phosphoenolpyruvic acid in the chloroplasts of mesophyll cells, leading to the formation of 4-C compound, oxaloacetic acid with the help of enzyme phosphoenolpyruvate carboxylase.
2. It is converted to another 4-C compound, malic acid. It is transported to the chloroplasts of bundle sheath cells.
3. Malic acid (4-C) is converted to pyruvic acid (3-C) with the release of C02 in the cytoplasm. Thus, concentration of C02 increases in the bundle sheath cells.
4. Chloroplasts of these cells contain enzymes of Calvin cycle.
5. Because of high concentration of C02, RuBP carboxylase participates in Calvin cycle and not photorespiration.
6. Sugar formed in Calvin cycle is transported into the phloem.
7. Pyruvic acid generated in the bundle sheath cells re-enter mesophyll cells and regenerates
phosphoenolpyruvic acid by consuming one ATP.
8. Since this conversion results in the formation of AMP (not ADP), two ATP are required to regenerate ATP from AMP. Thus, C4 pathway needs 12 additional ATP.
9. The C3 pathway requires 18 ATP for the synthesis of one glucose molecule, whereas C4 pathway requires 30 ATP.
10. Thus, C4 plants are better photosynthesizers as compared to C3 plants as there is no photorespiration in these plants.

Question 24.
With the help of labelled diagram explain Kranz anatomy.

1. Anatomy of leaves of C4 plants is different from leaves of C3 plants.
2. C4 plants show Kranz anatomy.
3. In the leaves of such plants, there is a bundle sheath around the vascular bundles.
4. The chloroplasts in the bundle – sheath cells are large and without or less developed grana, where as in the mesophyll cells the chloroplasts are small but with well-developed grana.

Question 25.
Give reason. Why C4 plants are favoured in tropical regions?

1. C4 plants are favoured in tropical regions as they require 30 ATP to produce 1 molecule of glucose.
2. High temperature in tropical regions leads to closure of stomata to reduce rate of transpiration. Due to this availability of C02 decreases.
3. PEP carboxylase present in mesophyll cells can fix C02 even at low concentration. This helps the plant in efficient assimilation of atmospheric carbon dioxide.
4. C4 plants contain a special leaf anatomy called Kranz anatomy which minimizes the losses due to photorespiration.
5. It helps C4 plants to survive in conditions of high daytime temperatures, intense sunlight and low moisture.

Question 26.
With the help of suitable flowchart explain CAM.
Crassulacean Acid Metabolism (CAM).

1. It is one more alternative pathway of carbon fixation found in desert plants.
2. It was first reported in the family Crassulaceae, therefore called as CAM (Crassulacean Acid Metabolism).
3. In CAM plants, stomata are scotoactive i.e. active during night, hence initial C02 fixation occurs in night.
4. Thus, C4 pathway fix C02 at night and reduce C02 in day time via the C3 pathway by using NADPH formed during the day.
5. PEP caboxylase and Rubisco are present in the mesophyll cell (no Kranz anatomy).
6. Formation of malic acid during dark is called acidification (phase I).
7. Malate is stored in vacuoles during the night.
8. Malate releases C02 during the day for C3 pathway within the same cell is called deacidification (phase II).
9. Examples of CAM plants: Kalanchoe, Opuntia, Aloe etc.
10. The Chemical reactions of the carbon dioxide fixation and its assimilation are similar to that of C4 plants.

Question 27.
Describe ‘any two’ factors affecting the rate of photosynthesis.
External factors which affect photosynthesis are as follows:
1. Light:
a. It is an essential factor as it supplies the energy necessary for photosynthesis.
b. Quality and intensity of light affects the photosynthesis.
c. Highest rate of photosynthesis takes place in red light followed by blue light.
d. The rate of photosynthesis considerably decreases in plants which are growing under a forest canopy.
e. In most of the plants, photosynthesis is maximum in bright diffused sunlight.
f. Uninterrupted and continuous photosynthesis for a very long period of time may be sustained without any visible damage to the plant.

2. Carbon dioxide:
The main source of C02 in land plants is the atmosphere, which contains only 0.3% of the gas.
b. Under normal conditions of temperature and light, carbon dioxide acts as a limiting factor in photosynthesis.
c. Increase in concentration of CO2 increases the photosynthesis.
d. Increase in C02 to about 1% is advantageous to most of the plants.
e. Higher concentration of the gas has an inhibitory effect on photosynthesis.

3. Temperature:
a. Like all other physiological processes, photosynthesis also needs a suitable temperature.
b. The optimum temperature at which the photosynthesis is maximum is 25-30 °C. Except in plants like Opuntia, photosynthesis takes place at as high as 55 °C.
c. This is the maximum temperature. Minimum temperature is temperature at which photosynthesis process just starts.
d. In the presence of sufficient light and CO2, photosynthesis increases with the rise of temperature till it becomes maximum. After that there is a decrease or fall in the rate of the process.

4. Water:
a. Water is necessary for photosynthetic process.
b. An increase in water content of the leaf results in the corresponding increase in the rate of photosynthesis.
c. Thus, the limiting effect of water is not direct but indirect.
d. It is mainly due to the fact that it helps in maintaining the turgidity of the assimilatory cells and the proper hydration of their protoplasm.

Internal factors which affects photosynthesis are as follows:
1. Chlorophyll:
a. Though presence of chlorophyll is essential for photosynthesis but rate of photosynthesis is proportional to the quantity of chlorophyll present.
b. It is because of the fact that chlorophyll merely acts as a biocatalyst and hence a small quantity is quite enough to maintain the large bulk of the reacting substances.
2. Sugar:
The final product in the photosynthesis reaction is sugar and its accumulation in the cells slow down the process of photosynthesis.
3. Internal structures:
The thickness of cuticle and epidermis of the leaf, the size and distribution of intercellular spaces and the distribution of the stomata and the development of chlorenchyma and other tissues also affects the rate of photosynthesis.

Question 28.
Enlist the factors that affect the rate of photosynthesis.
External factors which affect photosynthesis are as follows:
1. Light:
a. It is an essential factor as it supplies the energy necessary for photosynthesis.
b. Quality and intensity of light affects the photosynthesis.
c. Highest rate of photosynthesis takes place in red light followed by blue light.
d. The rate of photosynthesis considerably decreases in plants which are growing under a forest canopy.
e. In most of the plants, photosynthesis is maximum in bright diffused sunlight.
f. Uninterrupted and continuous photosynthesis for a very long period of time may be sustained without any visible damage to the plant.

2. Carbon dioxide:
The main source of C02 in land plants is the atmosphere, which contains only 0.3% of the gas.
b. Under normal conditions of temperature and light, carbon dioxide acts as a limiting factor in photosynthesis.
c. Increase in concentration of CO2 increases the photosynthesis.
d. Increase in C02 to about 1% is advantageous to most of the plants.
e. Higher concentration of the gas has an inhibitory effect on photosynthesis.

3. Temperature:
a. Like all other physiological processes, photosynthesis also needs a suitable temperature.
b. The optimum temperature at which the photosynthesis is maximum is 25-30 °C. Except in plants like Opuntia, photosynthesis takes place at as high as 55 °C.
c. This is the maximum temperature. Minimum temperature is temperature at which photosynthesis process just starts.
d. In the presence of sufficient light and CO2, photosynthesis increases with the rise of temperature till it becomes maximum. After that there is a decrease or fall in the rate of the process.

4. Water:
a. Water is necessary for photosynthetic process.
b. An increase in water content of the leaf results in the corresponding increase in the rate of photosynthesis.
c. Thus, the limiting effect of water is not direct but indirect.
d. It is mainly due to the fact that it helps in maintaining the turgidity of the assimilatory cells and the proper hydration of their protoplasm.

Internal factors which affects photosynthesis are as follows:
1. Chlorophyll:
a. Though presence of chlorophyll is essential for photosynthesis but rate of photosynthesis is proportional to the quantity of chlorophyll present.
b. It is because of the fact that chlorophyll merely acts as a biocatalyst and hence a small quantity is quite enough to maintain the large bulk of the reacting substances.
2. Sugar:
The final product in the photosynthesis reaction is sugar and its accumulation in the cells slow down the process of photosynthesis.
3. Internal structures:
The thickness of cuticle and epidermis of the leaf, the size and distribution of intercellular spaces and the distribution of the stomata and the development of chlorenchyma and other tissues also affects the rate of photosynthesis.

Question 29.
Give the Blackman’s law of limiting factors.

1. The Blackman’s law of limiting factors states that when a process is conditioned as to its rapidity by a number of separate factors, the rate of the process is controlled by the pace of the “slowest factor”.
2. The slowest factor is that factor which is present in the lowest or minimum concentration in relation to others.
3. The law of limiting factor can be explained by taking two external factors such as carbon dioxide and light.
4. For example, a plant photosynthesizing at a fixed light intensity sufficient to utilize 10mg of C2 per hour only.
5. Photosynthetic rate goes on increasing when concentration of CO2 increases.
6. Further increase in CO2 concentration will not increase the rate of photosynthesis. In this case light becomes the limiting factor. Therefore, under such circumstances rate of photosynthesis can be increased only by increasing the light intensity.
7. This proves that the rate of photosynthesis responds to one factor alone at a time and there would be a sharp break in the curve and a plateau formed exactly at the point where another factor becomes limiting.
8. If any one of the other factors which is kept constant (e.g. Light) is increased, the photosynthetic rate increases again reaching the optimum where again another factor becomes limiting.

Question 44.
Multiple Choice Questions:

Question 1.
How many ATP molecules are required for synthesis of one glucose molecule using C4 pathway?
(A) 30
(B) 18
(C) 6
(D) 2
(A) 30

Question 2.
Photosynthesis is ________ reaction.
(A) oxidation
(B) reduction
(C) redox
(D) electrochemical
(C) redox

Question 3.
Photosynthesis is minimum in _______ light.
(A) green
(B) blue
(C) red
(D) yellow
(A) green

Question 4.
From the visible spectrum of light, which component is reflected by the green leaves?
(A) Blue
(B) Red
(C) Green
(D) Orange
(C) Green

Question 5.
Which of the following is not an accessory pigment?
(A) Chlorophyll-b
(B) Xanthophyll
(C) Chlorophyll-a
(D) Carotene
(C) Chlorophyll-a

Question 6.
The reaction centre of PS-II is ________ .
(A) Chi-a, 700
(B) Chi-a, 680
(C) Chi- a, 673
(D) Chi-a, 650
(B) Chi-a, 680

Question 7.
Light reactions occur in ______________ .
(A) stroma
(B) grana
(C) matrix
(D) fret
(B) grana

Question 8.
Dark reaction takes place in _____________ .
(A) Stroma
(B) Grana
(C) Matrix
(D) Thylakoid
(A) Stroma

Question 9.
In dark reaction, the first compound to accept C02 is ___________ .
(A) RUMP
(B) RUBP
(C) PGAL
(D) PGA
(B) RUBP

Question 10.
Which of the following is a photochemical reaction?
(A) Light reaction
(B) C3 pathway
(C) C4 pathway
(D) CAM pathway
(A) Light reaction

Question 11.
Which of the following is a biochemical reaction?
(A) Light reaction
(B) Cyclic electron transfer
(C) Photolysis of water
(D) Dark phase
(D) Dark phase

Question 12.
How many Calvin cycles are required to produce one molecule of glucose?
(A) 3
(B) 4
(C) 5
(D) 6
(D) 6

Question 13.
The first C02 acceptor in C4 pathway is _______ .
(A) Pyruvic acid
(B) PEPA
(C) OAA
(D) Malic acid
(B) PEPA

Question 14.
In C4 pathway, fixation of metabolic C02 occurs in which of the following cells?
(A) Bundle sheath cells
(B) Mesophyll cells
(C) Epidermal cells
(D) Cortical cells
(A) Bundle sheath cells

Question 15.
Which one of the following is C4 plant?
(A) Sunflower
(B) Soyabean
(C) Sugarcane
(D) Spinach
(C) Sugarcane

Question 16.
Due to photorespiration, approximately __________ of photosynthetically fixed C02 is lost.
(A) 25%
(B) 50%
(C) 60%
(D) 80%
(A) 25%

Question 17.
CAM plants are mostly ________________ .
(A) Tropical plants
(B) Succulents
(C) Monocots
(D) Mangroves
(B) Succulents

Question 18.
Which of the following factors is not limiting?
(A) C02 concentration
(B) Light intensity
(C) Temperature
(D) Oxygen
(D) Oxygen

Question 45.
Competitive Corner

Question 1.
In Hatch and Slack pathway, the primary C02 acceptor is _______________ .
(A) Rubisco
(B) Oxaloacetic acid
(C) Phosphoglyceric acid
(D) Phosphoenol pyruvate
(D) Phosphoenol pyruvate

Question 2.
One scientist cultured Cladophora in a suspension of Azotobacter and illuminated the culture by splitting light through a prism. He observed that bacteria accumulated mainly in the region of:
(A) Blue and red light
(B) Violet and green light
(C) Indigo and green light
(D) Orange and yellow light
Hint: Cladophora is green alga and Azotobacter is aerobic bacteria. Theodor Engelmann split light into its spectral components using a prism and detected that aerobic bacteria accumulated mainly in the region of blue and red light.
(A) Blue and red light

Question 3.
Clil-a and Chl-b shown maximum absorption in ________ regions of visible light.
(A) blue, violet and red
(B) red, indigo and green
(C) yellow, blue and red
(D) blue, violet and green
(A) blue, violet and red

Question 4.
The co-enzyme which acts as hydrogen acceptor during light reaction is ________ .
(A) PQ
(C) COQ

Question 5.
During cyclic photophosphorylation, formation of ATP occurs between which of the following two compounds?
(A) FRS → Ferredoxin
(B) Cytochrome b6 → Cytochrome f
(C) Cytochrome f → Plastocyanin
(D) Plastocyanin → Ionised Chi – a
(B) Cytochrome b6 → Cytochrome f

Question 6.
Which of the following is NOT a product of light reaction of photosynthesis?
(C) ATP
(D) Oxygen

Question 7.
A part of photosynthetically fixed CO2 goes back to the atmosphere due to _______.
(A) cyclic photophosphorylation
(B) noncyclic photophosphorylation
(C) dark reaction
(D) photorespiration
(D) photorespiration

Question 8.
The highest rate of Photosynthesis in green plants are in _____ and ______ region of light spectrum.
(A) yellow and orange
(B) green and violet
(C) red and blue
(D) violet and blue
(C) red and blue

Question 9.
Which one of the following is an essential factor for photophosphorylation?
(A) Sunlight
(B) Carbohydrate
(C) Oxygen
(D) Water
(A) Sunlight

Question 10.
Cyclic photophosphorylation will NOT take place in the absence of ________ .
(A) carotenoids
(B) chlorophyll-a
(C) xanthophylls
(D) phycoerythrin
(B) chlorophyll-a

Question 11.
Dark reaction of photosynthesis is a cyclic process as _______ is regenerated.
(A) RuBP
(B) C02
(C) Glucose
(D) PGA
(A) RuBP

Question 12.
Phosphoenol pyruvate (PEP) is the primary CO2 acceptor in:
(A) C3 plants
(B) C4 plants
(C) C2 plants
(D) C3 and C4 plants
(B) C4 plants

Question 13.
In members of family Crassulaceae ________ is regenerated from starch during night.
(A) Phosphoenol pyruvic Acid
(B) Pyruvic Acid
(C) Malic Acid
(D) Oxalo Acetic Acid
(A) Phosphoenol pyruvic Acid

Question 14.
With reference to factors affecting the rate of photosynthesis, which of the following statements are NOT correct?
(A) Light saturation for CO2 fixation occurs at 10% of full sunlight
(B) Increasing atmospheric CO2 concentration upto 0.05% can enhance C02 fixation rate
(C) C3 plants responds to higher temperatures with enhanced photosynthesis while C4 plants have much lower temperature optimum
(D) Tomato is a greenhouse crop which can be grown in CO2 enriched atmosphere for higher yield.
(C) C3 plants responds to higher temperatures with enhanced photosynthesis while C4 plants have much lower temperature optimum.

## Maharashtra Board Class 11 Physics Important Questions Chapter 8 Sound

Balbharti Maharashtra State Board 11th Physics Important Questions Chapter 8 Sound Important Questions and Answers.

## Maharashtra State Board 11th Physics Important Questions Chapter 8 Sound

Question 1.
State the different types of waves.

1. Waves which require a material medium for their propagation are called mechanical waves. Example: Sound waves, string waves, seismic waves, etc.
2. Waves which do not require material medium for their propagation are called electromagnetic waves. Example: Light waves, radio waves, y-rays, etc.
3. The wave associated with any object when it is in motion is called as matter wave.
4. Waves in which a disturbance created at one place travels to distant points and keeps travelling unless stopped by an external force are known as travelling or progressive waves.
5. Waves are also of stationary type.

Question 2.
Define the following terms. Give their SI units.
i. Period
ii. Frequency
iii. Velocity
i. Period (T):
The time taken by the particle of a medium to complete one vibration is called period of the wave.
SI unit: second (s)

ii. Frequency (n):
The number of vibrations performed by a particle per second is called frequency of a wave.
SI unit: hertz (Hz)

iii. Velocity (v):
The distance covered by a wave per unit time is called the velocity of the wave.
SI unit: m/s

Question 3.
State the properties that should be possessed by a medium for a mechanical wave to propagate through it.

1. The medium must be continuous and elastic so that it can regain its original state as soon as the deforming forces are removed.
2. The medium should possess inertia. It must be capable of storing energy and transferring it in the form of waves.
3. The frictional resistance of the medium should be negligible to avoid damped oscillations.

Question 4.
What are two types of progressive waves? State two characteristics of progressive waves.
Progressive waves are classified into two types:
a. Transverse progressive waves
b. Longitudinal progressive waves.

Characteristics of progressive waves:
1. All the vibrating particles of medium have same amplitude, period and frequency.
2.. State of oscillation i.e., phase changes from particle to particle.

Question 5.
A violin string emits sound of frequency 510 Hz. How far will the sound waves reach when string completes 250 vibrations? The velocity of sound is 340 m/s.
Given: n = 510 Hz, v = 340 m/s,
number of vibrations = 250
To find: Distance
Formula: v = nλ
Calculation:
From formula,
λ = $$\frac {v}{n}$$ = $$\frac {340}{510}$$ = $$\frac {2}{3}$$ m
Distance covered in 1 vibration = $$\frac {2}{3}$$ m
∴ Distance covered in 250 vibration
= $$\frac {2}{3}$$ × 250 = 166.7 m 3
Answer: The distance covered by sound waves is 166.7 m

Question 6.
The speed of sound in air is 330 m/s and that in glass is 4500 m/s. What is the ratio of the wavelength of sound of a given frequency in the two media?
Given: vair = 330 m/s, vglass = 4500 m/s
To find: $$\frac {λ_{air}}{λ_{glass}}$$
Formula: v = nλ
Calculation: From formula,
vair = n λair
vglass = n λglass
∴ $$\frac {λ_{air}}{λ_{glass}}$$ = $$\frac {v_{air}}{v_{glass}}$$ = $$\frac {330}{4500}$$ = 7.33 × 10-2

Question 7.
The velocity of sound in gas is 498 m/s and in air is 332 m/s. What is the ratio of wavelength of sound waves in gas to air?
vg = 498 m/s, va = 332 m/s
To find: Ratio of wavelengths ($$\frac {λ_g}{λ_a}$$)
Formula: v = nλ
Calculation:
Frequency of sound wave remains same.
From formula,
For gas λg = $$\frac {v_g}{n}$$ and for air λag = $$\frac {v_a}{n}$$
∴ $$\frac {v_g}{v_a}$$ = $$\frac {v_g}{v_a}$$ = $$\frac {498}{332}$$ = $$\frac {3}{2}$$
∴ $$\frac {v_g}{v_a}$$ = 3 : 2

Question 8.
A human ear responds to sound waves of frequencies in the range of 20 Hz to 20 kHz. What are the corresponding wavelengths, if the speed of sound in air is 330 m/s? Answer:
Given: v1 = vg = 330 m/s, n1 = 20 Hz,
n2 = 20 kHz = 20 × 10³ Hz
To find: Wavelength (λ1 and λ2)
Formula: v = nλ
Calculation:
From formula,
λ1 = $$\frac {v_1}{n_1}$$ = $$\frac {330}{20}$$ = 16.5 m
λ2 = $$\frac {v_2}{n_2}$$ = $$\frac {330}{20×10^3}$$ = 16.5 × 10-3 = 0.0165 m

Question 9.
A bat emits ultrasonic sound of frequency 1000 kHz in air. If the sound meets a water surface, what is the wavelength of (i) the reflected sound, (ii) the transmitted sound? Speed of sound in air is 340 m s-1 and in water is 1486 m s-1
Given: n = 1000 kHz = 106 Hz,
va = 340 m/s,
vw = 1486 m/s
To find: Reflected wavelength (λR),
Transmitted wavelength (λT),
Formula: v = nλ
Calculation:
In different medium, frequency of sound wave remains same.
From formula,
Sound is reflected in air,
i. ∴ λR = $$\frac {v_a}{n}$$ = $$\frac {330}{10^6}$$ = 3.4 × 10-4 m
Sound is transmitted in water,
ii. ∴ λT = $$\frac {v_w}{n}$$ = $$\frac {1486}{10^6}$$ = 1.486 × 10-3 m

Question 10.
The wavelength of a sound note is 1 m in air and 2.5 m in a liquid. Find the speed of sound in the liquid, if the speed of the sound in air is 330 m/s.
Given: λa = 1 m, λl = 2.5 m, va = 330 m/s,
To find: Speed of sound (vl)
Formula: v = nλ
Calculation:
From formula,
Since the frequency n remains the same,
va = nλa and vl = nλl
∴ $$\frac {v_l}{v_a}$$ = $$\frac {λ_l}{λ_a}$$
∴ vl = va $$\frac {λ_l}{λ_a}$$ = 330 × $$\frac {2.5}{1}$$ = 825 m/s

Question 11.
Define a polarised wave.
A wave in which the vibrations of all the particles along the path of a wave are constrained to a single plane is called a polarised wave.

Question 12.
Write down the main characteristics of longitudinal waves.
Characteristics of longitudinal waves:

1. All the particles of medium in the path of wave vibrate in a direction parallel to the direction of propagation of wave with same period and amplitude.
2. When longitudinal wave passes through a medium, the medium is divided into alternate compressions (high pressure zone) and rarefactions (low pressure zone).
3. A compression and adjacent rarefaction form one cycle of a longitudinal wave. The distance between any two consecutive points having same phase (successive compression or rarefactions) is called wavelength of the wave.
4. For propagation of longitudinal waves, the medium should possess the property of elasticity of volume (bulk modulus). Thus, longitudinal waves can travel through solids, liquids and gases. Longitudinal wave cannot travel through vacuum or empty space.
5. The compressions and rarefactions advance in the medium and are responsible for transfer of energy.
6. When longitudinal wave advances through medium, there is periodic variations in pressure and density along the path of wave and with time.
7. Since the direction of vibration of particles and direction of propagation of wave are same or parallel, longitudinal waves cannot be polarised.

Question 13.
State the mathematical expression for a transverse progressive wave travelling along the positive and negative x-axis.
i. Consider a transverse progressive wave whose particle position is described by x and displacement from equilibrium position is described by y.
Such a sinusoidal wave can be written as follows:
∴ y (x, t) = a sin (kx – ωt + ø) ……… (1)
where a, k, ω and ø are constants,
y (x, t) = displacement as a function of position (x) and time (t)
a = amplitude of the wave,
ω = angular frequency of the wave
(kx0 – ωt + ø) = argument of the sinusoidal wave and is the phase of the particle at x at time t.

ii. At a particular instant, t = t0,
y (x, t0) = a sin (kx – ωt0 + ø)
= a sin (kx + constant)
Thus at t = t0, shape of wave as a function of x is a sine wave.

iii. At a fixed location x = x0
y(x0, t) = a sin (kx0 – ωt + ø)
= a sin (constant – ωt)
Hence the displacement y, at x = x0 varies as a sine function.

iv. This means that the particles of the medium, through which the wave travels, execute simple harmonic motion around their equilibrium position.

v. For (kx – ωt + ø) to remain constant, x must increase in the positive direction as time t increases. Thus, the equation (1) represents a wave travelling along the positive x axis.

vi. Similarly, a wave travelling in the direction of the negative x axis is represented by,
y(x, t) = a sin (kx + ωt +ø) …….(2)

Question 14.
Explain the Laplace’s correction to the Newton’s formula for the velocity of sound in air.
Laplace’s correction:
Laplace suggested that the compression or rarefaction takes place too rapidly. Heat produced during compression and lost during rarefaction does not get sufficient time for dissipation. Due to this, the whole heat content remains same. Thus, it is an adiabatic process.

According to Laplace, E is the adiabatic modulus of elasticity of air medium which is given by,
E = γP ….(1)
where P = pressure of the air medium γ = ratio of specific heat of air at constant pressure (cp) and specific heat of air at constant volume (cv). i.e., γ = cp/cv.

iii. Using equation, v = $$\sqrt{\frac {E}{ρ}}$$, we have velocity of sound in air,
v = $$\sqrt{\frac {γP}{ρ}}$$, …. [From equation (1)]
For air, γ = 1.41
At NTP, P = 0.76 × 13600 × 9.8 N/m²
ρ = 1.293 kg/m³.
∴ v = $$\sqrt{\frac {1.41×0.76×13600×9.8}{1.293}}$$ = 332.35 m/s
This value is in close agreement with the experimental value.

Question 15.
What is the effect of temperature on the velocity of sound in air?
Effect of temperature on velocity of sound:
i. Let v0 and v be the velocity of sound in air at T0 and T Kelvin respectively. Let ρ0 and p be the densities of gas at temperature T0 and T respectively.

ii. Considering the number of moles n = 1 for the gas, we have,

iii. From above formula, we can conclude that velocity of sound in air increases with increase in temperature.

Question 16.
Show that for 1 °C rise in temperature, the velocity of sound in air increases by 0.61 m/s.
Let v0 = velocity of sound at 0 °C or 273 K
v = velocity of sound at t °C or (273 + 1) K
we have, v ∝ √T

Hence, velocity of sound increases by 0.61 m/s when temperature increases by 1 °C.

Question 17.
Suppose you are listening to an out-door live concert sitting at a distance of 150 m from the speakers. Your friend is listening to the live broadcast of the concert in another country and the radio signal has to travel 3000 km to reach him. Who will hear the music first and what will be the time difference between the two? Velocity of light = 3 × 108 m/s and that of sound is 330 m/s.
Distance between me and the speakers
(s1) = 150 m, distance radio signal has to travel (S2) = 3000 km, vsound 330 m/s, vlight = 3 × 108 m/s
Time taken by sound to reach me,
= $$\frac {s_1}{v_sound}$$ = $$\frac {150}{330}$$ = 0.4546 s
Time taken by the broadcasted sound (done by
EM waves = $$\frac {s_2}{v_light}$$ = $$\frac {3000km}{30×10^5km/s}$$ = $$\frac {3×1^30}{3×10^5}$$ = 10-2 s
∴My friend will hear the sound first.
The time difference will be = 0.4546 – 0.01
= 0.4446 s.

Question 18.
Consider a closed box of rigid walls so that the density’ of the air inside it is constant. On heating, the pressure of this enclosed air is increased from P0 to P. It is now observed that sound travels 1.5 times faster than at pressure P0. Calculate P/P0.
Given: vP = 1.5 vP0
To find: Ratio of pressure ($$\frac {p}{p_0}$$)

Question 19.
The densities of nitrogen and oxygen at NTP are 1.25 kg/m³ and 1.43 kg/m³ respectively. If the speed of sound in oxygen at NTP is 320 m/s, calculate the speed in nitrogen, under the same conditions of temperature and pressure, (γ for both the gases is 1.4)
Given: ρN = 1.25 kg/m³, ρ = 1.43 kg/m³,
v0 = 320 m/s,
To find: Speed in nitrogen (vN)
Formula: v = ($$\sqrt{\frac {γP}{ρ}}$$ )
Calculation: From formula,

Question 20.
Find the temperature at which the velocity of sound in air will be 1.5 times its velocity at 0 °C
Given: $$\frac {p}{p_0}$$ = 1.5, T0 = 0 °C = 273 K
To find: Temperature (T)
Formula: $$\frac {v}{v_0}$$ = $$\sqrt{\frac {T}{T_0}}$$
Calculation:
From formula,
$$\frac {T}{T_0}$$ = ($$\frac {v}{v_0}$$)²
∴ T = T0 ($$\frac {v}{v_0}$$)²
∴ T = 273 (1.5)² = 614.25 K = 341.25 °C

Question 21.
The velocity of sound in air at 27 °C is 340 m/s. Calculate the velocity of sound in air at 127 °C.
Given: T1 = 27 °C = 27 + 273 = 300 K,
v1 = 340 m/s,
T2 = 127 °C = 127 + 273 = 400 K
To find: Velocity (v2)
Formula: $$\frac {v_1}{v_2}$$ = $$\sqrt{\frac {T_1}{T_2}}$$
Calculation: From formula,
v2 = v1 $$\sqrt{\frac {T_2}{T_1}}$$ = 340, $$\sqrt{\frac {400}{300}}$$
= 340 × 1.1547
∴ v2 = 392.6 m/s

Question 22.
The wavelength of a note is 27 m in air when the temperature is 27 °C. What is the wavelength when the temperature is increased to 37 °C?
Given: λ1 = 27 m,
T1 = 27 °C = 273 + 27 = 300 K,
T2 = 37 °C = 273 + 37 = 310 K
To find: Wavelength (λ2)

Question 23.
We cannot hear an echo at every place. Give reason.

1. Echo of sound depends upon the temperature of the surrounding and distance between source and reflecting surface.
2. To hear a distinct echo at 22 °C, the minimum distance required between the source of sound and reflecting surface should be 17.2 metre.
3. The velocity of sound depends on the temperature of air. Thus, the minimum distance will change with temperature. Hence, we cannot hear an echo at every place.

Question 24.
Write a short note on reverberation.

1. Reverberation is the phenomenon in which sound waves are reflected multiple times causing a single sound to be heard more than once.
2. Sound wave gets reflected multiple times if the distance between reflecting surface and source of sound is less than 15 m.
3. During reverberation, the time interval between the successive reflections of a sound is small.
4. As a result, the reflected sound waves overlap and produce a continuously increasing loud sound which is at times difficult to understand. Measures to decrease reverberation:
5. Reverberation can be decreased by making the walls and roofs rough and by using curtains in the hall to avoid reflection of sound.
6. Chairs and wall surfaces should be covered with sound absorbing materials.
7. Porous cardboard sheets, perforated acoustic tiles, gypsum boards, thick curtains etc. should be used on the ceilings and walls.

Question 25.
Define acoustics.
The branch of physics which deals with the study of production, transmission and reception of sound is called acoustics.

Question 26.
State the conditions that must be satisfied for proper acoustics in an auditorium along-with their remedies.
i. Acoustics of an auditorium should be such that the sound is heard sufficiently loudly at all the points in the auditorium. The surface behind the speaker should be parabolic with the speaker at its focus for uniform distribution of sound in the auditorium. Reflection of sound helps to maintain good loudness through the entire auditorium.

ii. Echoes and reverberations should be reduced. More absorptive reflecting surfaces and full auditoriums help in reducing echoes.

iii. Unnecessary focusing of sound, poor audibility zone or region of silence should be avoided. Curved surface of the wall or ceiling should be avoided for this purpose.

iv. Echelon effect which arises due to the mixing of sound produced in the hall by the echoes of sound produced in front of regular structure like stairs should be reduced. Stair type construction in the hall must be avoided for this purpose.

v. To avoid outside stray sound from entering, the auditorium should be sound-proof when closed.

vi. Inside fittings, seats, etc. should not produce any sound for proper acoustics. Air conditioners instead of fans and soft action door closers should be used.

Question 27.
State the applications of acoustics observed in nature.
Application of acoustics in nature:
i. Bats apply the principle of acoustics to locate objects. They emit short ultrasonic pulses of frequency 30 kHz to 150 kHz. The resulting echoes give them information about location of the obstacle. This helps the bats to fly in even in total darkness of caves.

ii. Dolphins navigate underwater with the help of an analogous system. They emit subsonic frequencies which can be about 100 Hz. They can sense an object about 1.4 m or larger.

Question 28.
State the medical applications of acoustics.
i. High pressure and high amplitude shock waves are used to split kidney stones into smaller pieces without invasive surgery. A reflector or acoustic lens is used to focus a produced shock wave so that as much of its energy as possible converges on the stone. The resulting stresses in the stone causes the stone to break into small pieces which can then be removed easily.

ii. Ultrasonic imaging uses reflection of ultrasonic waves from regions in the interior of body. It is used for prenatal (before the birth) examination, detection of anomalous conditions like tumour etc. and the study of heart valve action.

iii. Ultrasound at a very high-power level, destroys selective pathological tissues which is helpful in treatment of arthritis and certain type of cancer.

Question 29.
State the underwater applications of acoustics.

1. SONAR (Sound Navigational Ranging) is a technique for locating objects underwater by transmitting a pulse of ultrasonic sound and detecting the reflected pulse.
2. The time delay between transmission of a pulse and the reception of reflected pulse indicates the depth of the object.
3. Motion and position of submerged objects like submarine can be measured with the help of this system.

Question 30.
State the applications of acoustics in environmental and geological studies.
i. Acoustic principle has important application to environmental problems like noise control. The quiet mass transit vehicle is designed by studying the generation and propagation of sound in the motor’s wheels and supporting structures.

ii. Reflected and refracted elastic waves passing through the Earth’s interior can be measured by applying the principles of acoustics.

iii. This is useful in studying the properties of the Earth. Principles of acoustics are applied to detect local anomalies like oil deposits etc. making it useful for geological studies.

Question 31.
A man shouts loudly close to a high wall. He hears an echo. If the man is at 40 m from the wall, how long after the shout will the echo be heard? (speed of sound in air = 330 m/s)
Given s = 40m, v = 330 m/s
To Find: time (t)
Formula: Time = distance $$\frac {distence}{speed}$$
Calculation:
The distance travelled by the sound wave
= 2 × distance from man to wall.
= 2 × 40 = 80 m.
From formula,
∴ Time taken to travel the distance
$$\frac {distence}{speed}$$ = $$\frac {80}{30}$$ = 0.24 s

Question 32.
Write a short note on pitch of sound note.

1. Pitch refers to the sharpness or shrillness of sound.
2. Increase in frequency of sound results in increase in the pitch and the sound is said to be sharper.
3. Tone refers to a single frequency of a wave.
4. A note may contain single or multiple tones.
5. High frequency is generally referred as high pitch or high tone.
6. Generally, speech of the men is of low pitch (shrill) and that of the women is of high pitch (sharp). Tones of an acoustic guitar are sharper than that of a base guitar. Sound of table is sharper than that of a dagga.

Question 33.
Write a short note on quality (timbre) of sound note.
i. Timbre of a sound refers to the quality of the sound which depends upon the mixture of tones and overtones in the sound. Same sound played on different musical instruments feels significantly different and the musical instrument from which the sound generated can be easily identified.

Question 34.
Write a short note on loudness of sound.
OR
Explain how loudness affects the characteristics of sound.
Loudness:
i. Loudness depends upon the intensity of vibration.

ii. Intensity of a wave is proportional to square of the amplitude (I ∝ A²) and is measured in the (SI) unit ofW/m²

iii. The human response to intensity is not linear, i.e., a sound of double intensity is louder but not doubly loud.

iv. Under ideal conditions, for a perfectly healthy human ear, the least audible intensity is I0 = 10-12 W/m².

v. Loudness of a sound of intensity I (measured in unit bel) is given by,
L2 = log10 ($$\frac {I}{I_0}$$) ………….. (1)

vi. Decibel is the commonly used unit for loudness.

vii. As, 1 decibel or 1 dB = 0.1 bel.
∴ 1 bel = 10 dB. Thus, loudness in dB is 10 times loudness in bel.
∴ LdB = 10Lbel = 10 log10 ($$\frac {I}{I_0}$$)
For sound of least audible intensity I0
LdB = 10 log10 ($$\frac {I_0}{I_0}$$) = 10 log10 (1) = 0 ………… (2)
This corresponds to threshold of hearing.

viii. For sound of 10 dB,
10 = 10 log10 ($$\frac {I}{I_0}$$)
∴ ($$\frac {I}{I_0}$$) = 10 1 or I = 10 I0
For sound of 20 dB,
20 = 10 log10 ($$\frac {I}{I_0}$$)
= ($$\frac {I}{I_0}$$) = 10² or I = 100 I0 and so on.

ix. This implies, loudness of 20 dB sound is felt double that of 10 dB, but its intensity is 10 times that of the 10 dB sound. Similarly, 40 dB sound is left twice as loud as 20 dB sound but its intensity is 100 times as that of 20 dB sound and 10000 times that of 10 dB sound. This is the power of logarithmic or exponential scale. If we move away from a (practically) point source, the intensity of its sound varies inversely with square of the distance, i.e., I ∝ $$\frac {1}{r^2}$$.

Question 35.
When heard independently, two sound waves produce sensations of 60 dB and 55 dB respectively. How much will the sensation be if those are sounded together, perfectly in phase?
L1 = 60 dB = 10 log10 $$\frac {I_1}{I_0}$$
∴ $$\frac {I_1}{I_0}$$ = 106
∴ I1 = 106I0
Similarly, I2 = 105.5 I0
As the waves combine perfectly in phase, the vector addition of their amplitudes will be given by A² = (A1 + A2)² = A$$_1^2$$ + A$$_2^2$$ + 2A1, A2 As intensity is proportional to square of the amplitude.
∴ I = I1 + I2 + 2$$\sqrt {I_1I_2}$$ = 105 I0 (101 +100.5 + 2$$\sqrt {10^{1.5}}$$)
= 105I0(10 + 3.1623 +2 × 100.75)
= 24.41 × 105I0 = 2.441 × 106I0
∴ L = 10 log10 ($$\frac {I}{I_0}$$) = 10 log10 (2.441 × 106)
= 10[log10 (2.441) + log10(106)]
= 10(0.3876 + 6)
L = 63.876 dB ~ 64 dB

Question 36.
The noise level in a class-room in absence of the teacher is 50 dB when 50 students are present. Assuming that on the average each student outputs same sound energy per second, what will be the noise level if the number of students is increases to 100?
Loudness of sound is given as,

∴ LB – LA = 0.301 × 10 = 3.01
∴ LB = LA + 3.01 = 53.01 dB

Question 37.
Calculate the decibel increase if there is a two-fold increase in the intensity of a wave. (Given: log10 2 = 0.3010)
L = 10 log10 $$\frac {I}{I_0}$$ decibel
L’ = 10 log10 $$\frac {2I}{I_0}$$ decibel
L’ – L = 10 (log10 $$\frac {2I}{I_0}$$ – log10 ($$\frac {I}{I_0}$$)
= 10 log10 2
= 10 × 0.3010
∴ L’ – L = 3.01 dB

Question 38.
Derive the expression for apparent frequency when listener is stationary and source is moving away from the listener.

i. Consider a source of sound S moving away from a stationary listener L with velocity vs. Let the speed of sound with respect to the medium be v (always positive). The listener uses a detector for counting each wave crest that reaches it.

ii. Let at t = 0, the source at point Si which is at a distance d from the listener, emit a crest. This crest reaches the listener at time t1, given as, t1 = d/v. …………(1)

iii. Let T0 be the time period at which the waves are emitted.
At t = T0, distance travelled by the source away from the stationary listener to reach point S2 = vsT0.
∴ Distance of point S2 from the listener = d + vsT0.
At S2, The source emits second crest. This crest reaches the listener at t2, given as,
t2 = T0 + ($$\frac {d+v_sT_0}{v}$$) …………. (2)

iv. Similarly, the time taken by the (p+1)th crest (where, p is an integer, p = 1, 2, 3,…), emitted by the source at time pT0, to reach the listener is given as,
tp+1 = pT0 + ($$\frac {d+pv_sT_0}{v}$$) …………. (3)
∴ the listener’s detector counts p crests in the time interval,
tp+1 – t1 = pT0 + ($$\frac {d+pv_sT_0}{v}$$) – $$\frac {d}{v}$$
The period of wave as recorded by the listener is,

Where, n = frequency recorded by the listener (apparent frequency)
n0 = frequency emitted by the source (actual frequency).
This is the expression for apparent frequency when the listener is stationary and the source is moving away from the listener.

Question 39.
Derive an expression for apparent frequency when listener is stationary and source is moving towards the listener.

i. Consider a source of sound S moving towards a stationary listener L with velocity vs. Let the speed of sound with respect to the medium be v (always positive). The listener use a detector for counting each wave crest that reaches it.

ii. Let at t = 0, the source at point S1 which is at a distance d from the listener, emit a Crest. This crest reaches the listener at time t1, given as,
∴ t1 = d/v. ……….(1)

iii. Let T0 be the time period at which the waves are emitted.
At t = T0, distance travelled by the source away from the stationary listener to reach point S2 = vsT0.
Distance of S2 from the listener = d – vsT0.
At S2, The source emits second crest. This crest reaches the listener at
t2 = T0 + ($$\frac {d-v_sT_0}{v}$$) ………….. (2)

iv. Similarly, the time taken by the (p+1)th crest (where, p = 1,2,3,…), emitted by the source at time pT0, to reach the listener is given as,
tp+1 = pT0 + ($$\frac {d-pv_sT_0}{v}$$) ……………. (3)
∴ the listener’s detector counts p crests in the time interval,
tp+1 – t1 = pT0 + ($$\frac {d-pv_sT_0}{v}$$) – $$\frac {d}{v}$$
∴ the period of wave as recorded by the listener is,

Where, n = frequency recorded by the listener (apparent frequency)
n0 = frequency emitted by the source (actual frequency).
This is the expression for apparent frequency when the listener is stationary and the source is moving towards the listener.

Question 40.
Derive the expression for apparent frequency when the source is stationary and the listener is moving towards the source.

i. Consider a listener approaching a stationary source S with velocity vL as shown in figure. Let the speed of sound with respect to the medium be v (always positive).

ii. Let at time t = 0, the source emits the first wave when the listener L1 is at an initial distance d from the source.
At time t = t1 the listener receives the first wave at the position L2.
Distance travelled by the listener towards the stationary source during time t1 = vLt1.
Distance travelled by the sound wave during time t1 = d – vLt1
∴ time taken by the sound wave to travel this distance, t1 = $$\frac {d-v_Lt_1}{v}$$
∴ t1 = $$\frac {d}{v+v_L}$$ ………….. (1)

iii. Let at time t = T0 (time period of the waves emitted by the source), the source emits a second wave.
At t = t2, the listener receives the second wave. Distance travelled by the listener towards the stationary source during time t2 = vLt2.
Distance travelled by the sound wave during time t2 = d – vLt2
∴ time taken by the sound wave to travel this distance = $$\frac {d-v_Lt_2}{v}$$
However, this time should be counted after T0, as the second wave was emitted at t = T0.
∴ t2 = T0 + $$\frac {d-v_Lt_2}{v}$$
∴ t2 = $$\frac {vT_0+d}{v+v_L}$$ …………. (2)

iv. Similarly, for the third wave, we get,
t3 = 2T0 + $$\frac {d-v_Lt_3}{v}$$
∴ t3 = $$\frac {2vT_0+d}{v+v_L}$$ …………. (3)

v. Extending this argument to the (p + 1)th wave, we get,
tp+1 = pT0 + $$\frac {d-v_Lt_{p+1}}{v}$$
∴ tp+1 = $$\frac {pvT_0+d}{v+v_L}$$ …………. (4)

vi. The observed or recorded period T is the time duration between instances of receiving successive waves.

This is the expression for apparent frequency when the source is stationary and the listener is moving towards the source.

Question 41.
Derive the expression for apparent frequency when the source is stationary and the listener is moving away from the source.

i. Consider a listener moving away a stationary source S with velocity VL. Let the speed of sound with respect to the medium be y (always positive).

ii. Let at time t = 0, the source emits the first wave when the listener L1 is at an initial distance d from the source.
At time t = t1 the listener receives the first wave at the position L2.
Distance travelled by the listener away from the stationary source during time t1 = vLt1.
Distance travelled by the sound wave during time t1 = d + vLt1
∴ time taken by the sound wave to travel this distance,
t1 = $$\frac {d+v_Lt_1}{v}$$
∴ t1 = $$\frac {d}{v-v_L}$$ ………….. (1)

iii. Let at time t = T0 (time period of the waves emitted by the source), the source emits a second wave.
At t = t2, the listener receives the second wave. Distance travelled by the listener away from the stationary source during time t2 = vLt2.
∴ Distance travelled by the sound wave during time t2 = d + vLt2.
∴ time taken by the sound wave to travel this distance = $$\frac {d+v_Lt_2}{v}$$
However, this time should be counted after T0, as the second wave was emitted at t = T0.
∴ t2 = T0 $$\frac {d+v_Lt_2}{v}$$ ………….. (2)
∴ t2 = $$\frac {vT_0+d}{v-v_L}$$

iv. Similarly for the third wave, we get
t3 = 2T0 $$\frac {d+v_Lt_3}{v}$$
∴ t3 = $$\frac {2vT_0+d}{v-v_L}$$ …………..(3)

v. Extending this argument to the (p + 1)th wave, we get,
tp+1 = pT0 + $$\frac {d+v_Lt_{p+1}}{v}$$
∴ tp+1 = $$\frac {pvT_0+d}{v-v_L}$$ …………..(4)

vi. The observed or recorded period T is the time duration between instances of receiving successive waves.

This is the expression for apparent frequency when the source is stationary and the listener is moving away from the source.

Question 42.
State the common properties between Doppler effect of sound and light.
i. The recorded frequency is different than the emitted frequency in case of relative motion between listener (or observer) and source (of sound or light waves).

ii. In case of relative approach, recorded frequency > emitted frequency.

iii. In case of relative recede, recorded frequency < emitted frequency.

iv. For values of listener velocity (vL) or source velocity (vs) much smaller then wave speed (speed of sound or light).
n = n0 (1±$$\frac {v_r}{v}$$)
Where, vr = relative velocity
n = actual frequency of the source
n0 = apparent frequency of the source
v = velocity of sound in air.
(upper sign is used during relative approach and lower sign is during relative recede.)

v. If velocities of source and observer (listener) are along different lines, their respective components along the line joining them should be chosen for longitudinal Doppler effect and the same mathematical treatment is applicable.

Question 43.
State the major difference between Doppler effects of sound and light.

1. Speed of light being absolute, only relative velocity between the observer and the source matter irrespective of who is in motion. However, for obtaining exact Doppler shift for sound waves, it is absolutely important to know who is in motion.
2. In case of light, classical and relativistic Doppler effects are different while sound only has classical doppler effect.
3. Presence of wind affects the velocity of sound which affects the Doppler shift in sound.

Question 44.
A train, standing at the outer signal of a railway station blows a whistle of frequency 400 Hz in still air. (i) What is the frequency of the whistle for a platform observer when the train (a) approaches the platform with a speed of 10 m s-1 (b) recedes from the platform with a speed of 10 m s-1? (ii) What is the speed of sound in each case? The speed of sound in still air can be taken as 340 m s-1.
Given: vs = 10 m/s, v = 340 m/s, n0 = 400 Hz
Apparent frequency (n), velocity of sound (vs) in each case
Formulae:
i. n = n0 ($$\frac {v}{v-v_s}$$)
ii. n = n0 $$\frac {v}{v+v_s}$$
Calculation:
a. As the train approaches the platform, using formula (i),
n = 400 ($$\frac {340}{340-10}$$) = 421.12 Hz

b. As the train recedes from the platform, using formula (ii),
n = 400 ($$\frac {340}{340+10}$$) = 388.57 Hz

ii. The relative motion of source and observer results in the apparent change in the frequency but has no effect on the speed of sound. Hence, the speed of sound remains unchanged in both the cases.

Question 45.
A train blows a whistle of frequency 640 Hz in air. Find the difference in apparent frequencies of the whistle for a stationary observer, when the train moves towards and away from the observer with the speed of 72 km/hour. (Speed of sound in air = 340 m/s)
Given: vs = 72 km/ hr = 20 m/s, n0 = 640 Hz,
v = 340 m/s
To find: Difference in apparent frequencies
(nA – n’A)
Formulae:
i. When the train moves towards the stationary observer then,
nA = n0 ($$\frac {v}{v-v_s}$$)
ii. When the train moves away the stationary observer then,
n’A = n0 ($$\frac {v}{v+v_s}$$)
Calculation: From formula (i),
nA = 640 ($$\frac {340}{340-20}$$)
∴ nA = 680 Hz
From formula (ii),
n’A = 640 ($$\frac {340}{340+20}$$)
∴ n’A = 604.4 Hz
Difference between nA and n’A
= nA – n’A = 75.6 Hz

Question 46.
The speed limit for a vehicle on road is 120 km/hr. A policeman detects a drop of 10% in the pitch of horn of a car as it passes him. Is the policeman justified in punishing the car driver for crossing the speed limit? (Given: Velocity of sound=340 m/s).
Given: Speed limit, vL = 120 km/hr
n’A = nA – $$\frac {10}{100}$$ nA = 0.9 nA
Velocity of sound, v = 340 m/s
To Find: Velocity of source (vs)
i. nA = ($$\frac {v}{v-v_s}$$)n
ii. n’A = ($$\frac {v}{v+v_s}$$)n
Calculation:
Dividing formula (i) by (ii),

Question 47.
A stationary source produces a note of frequency 350 Hz. An observer in a car moving towards the source measures the frequency of sound as 370 Hz. Find the speed of the car. What will be the frequency of sound as measured by the observer in the car if the car moves away from the source at the same speed? (Assume speed of sound = 340 m/s)
Given: n0 = 350 Hz, v = 340 m/s,
nA = 370 Hz
To find: Speed (vL), Frequency (nA)
Formulae:
i. When the car moves towards the stationary source then,
nA = n0 ($$\frac {v+v_s}{v}$$)

ii. When the car moves away from the stationary source then,
nA = n0 ($$\frac {v-v_L}{v}$$)
Calculation: From formula (i),
370 = 35o ($$\frac {340+v_L}{340}$$)
∴ 359.43 =340 +vL
∴ vL = 19.43 m/s
From formula (ii),
∴ nA = 35o ($$\frac {340-20}{340}$$) = $$\frac {35}{34}$$ × 320
∴ nA = 329.41 Hz

Question 48.
A train, standing in a station-yard, blows a whistle of frequency 400 Hz in still air. The wind starts blowing in the direction from the yard to the station with a speed of 10 m s-1. What are the frequency, wavelength, and speed of sound for an observer standing on the station’s platform? Is the situation exactly identical to the case when the air is still and the observer runs towards the yard at a speed of 10 m s-1? The speed of sound in still air can be taken as 340 m s-1.
Blowing of wind changes the velocity of sound. As the wind is blowing in the direction of sound, effective speed of sound ve = v + vw = 340 + 10 = 350 m/s
As the source and listener both are at rest, frequency is unchanged, i.e., n = 400 Hz.
∴ wavelength, λ = $$\frac {v_e}{n}$$ = $$\frac {350}{400}$$ = 0.875 m
For still air, vw = 0 and ve = v = 340 m/s
Also, as observer runs towards the stationary train vL = 10 m/s and vs = 0
The frequency now heard by the observer,
n = n0 ($$\frac {v+v_L}{v}$$) = 400 ($$\frac {340+10}{340}$$)
= 411.76 Hz
As the source is at rest, wavelength does not change i.e., λ’ = λ = 0.875 m
Comparing the answers, it can be stated that, the situations in two cases are different.

Question 49.
A SONAR system fixed in a submarine operates at a frequency 40 kHz. An enemy submarine moves towards the SONAR with a speed of 360 km h-1. What is the frequency of sound reflected by the submarine? Take the speed of sound in water to be 1450 m s-1.
Frequency of SONAR (source)
n = 40 kHz = 40 × 10³ Hz
Speed of sound waves, v = 1450 m s-1
Speed of the listener, vL = 360 km h-1
= 360 × $$\frac {5}{18}$$ ms-1
= 100 m s-1
Since, the source is at rest and the observer moves towards the source (SONAR).
We have,
n = n0 ($$\frac {v+v_L}{v}$$) = 40 × 10³ × ($$\frac {1450+100}{14540}$$)
∴ n = 4.276 × 10⁴ Hz
This frequency n’ is reflected by the enemy ship and is observed by the SONAR (which now acts as observer). Therefore, in this case vs = 100 m s-1
Apparent frequency,
n = n0 ($$\frac {v}{v-v_s}$$)
= 4.276 × 10⁴ × ($$\frac {1450}{1450-100}$$) = 4.59 × 10⁴ Hz
∴ n = 45.9 kHz

Question 50.
A rocket is moving at a speed of 220 m s-1 towards a stationary target. While moving, it emits a wave of frequency 1200 Hz. Some of the sound reaching the target gets reflected back to the rocket as an echo. Calculate (i) the frequency of the sound as detected by the target and (ii) the frequency of the echo as detected by the rocket (velocity of sound = 330 m/s)
Given: vs = 220 m/s, vL = 0 m/s, n = 1200 Hz
To find: Apparent frequency (n)
i. n = n0 ($$\frac {v}{v-v_s}$$)
ii. n = n0 $$\frac {v+v_L}{v}$$
Calculation: For first case, observer is stationary and source i.e., rocket is moving towards the target.
Hence, using formula (i),
frequency of sound as detected by the target,
n = 1200 ($$\frac {330}{330-220}$$) = 3600 Hz
For second case, target acts as a source with frequency 3600 Hz as it is the source of echo. While rocket detector acts as an observer. This means, vs = 0 and VL = 220 m/s
Using formula (ii),
frequency of echo as detected by the rocket,
n = 3600 ($$\frac {330+220}{330}$$) = 600 Hz

Question 51.
A bat is flying about in a cave, navigating via ultrasonic beeps. Assume that the sound emission frequency of the bat is 40 kHz. During one fast swoop directly towards a flat wall surface, the bat is moving at 0.03 times the speed of sound in air. What frequency does the bat hear reflected off the wall?
Here, frequency of sound emitted by bat,
n = 40 kHz
Velocity of bat, vs = 0.03 v
where v is velocity of sound.
The bat is moving towards the flat wall. This is the case of source in motion and the observer at rest.
Therefore, the frequency of sound reflected at the wall is,
n = ns ($$\frac {v}{v-v_s}$$) = n × ($$\frac {v}{v-0.03v}$$)
= n × $$\frac {1}{0.97}$$ = $$\frac {n}{0.97}$$
The frequency n’ is reflected by the wall and is again received by the bat moving towards the wall. This is the case of an observer moving towards the source with velocity vL = 0.03 v.
The frequency observed by bat,

Question 52.
A bat, flying at velocity VB = 12.5 m/s, is followed by a car running at velocity Vc = 50 m/s. Actual directions of the velocities of the car and the bat are as shown in the figure below, both being in the same horizontal plane (the plane of the figure). To detect the car, the bat radiates ultrasonic waves of frequency 36 kHz. Speed of sound at surrounding temperature is 350 m/s.

There is an ultrasonic frequency detector fitted in the car. Calculate the frequency recorded by this detector. The ultrasonic waves radiated by the bat are reflected by the car. The bat detects these waves and from the detected frequency, it knows about the speed of the car. Calculate the frequency of the reflected waves as detected by the bat. (sin 37° = cos 53° ~ 0.6, sin 53° = cos 37° ~ 0.8)
The components of velocities of the bat and the car, along the line joining them, are
vc cos 53° ~ 50 × 0.6 = 30 m s-1 and
vB cos 37° ~ 12.5 × 0.8 = 10 m s-1

Doppler shifted frequency n = n0 ($$\frac {v±v_1}{v±v_s}$$)
upper signs to be used during approach, lower signs during recede.
Case I: Frequency radiated by the bat
n0 = 36 × 10³ Hz,
The source (bat) is receding, while the listener (car) is approaching
vS = vB cos 37° = 10 m/s and
VL = vC cos 53° = 30 m/s
∴ Frequency detected by the detector in the car,
n = n0 ($$\frac {v+v_L}{v+v_s}$$)
∴ n = 36 × 10³ ($$\frac {350+30}{350+10}$$) = 36 × 10³ × $$\frac {38}{36}$$
∴ n = 38 × 10³ Hz = 38 kHz

Case II: The car is the source.
Emitted frequency by the car, is given as,
n0 = 38 × 10³ Hz,
Car, the source, is approaching the listener (bat).
Now bat-the listener is receding while car the source is approaching,
∴ vs = vc cos 53° = 30 m/s
∴ vL = vB cos 37° = 10 m/s
∴ n = n0 ($$\frac {v-v_L}{v-v_s}$$)
∴ n = 38 × 10³ ($$\frac {350-10}{350-30}$$) = 38 × 10³ × $$\frac {34}{33}$$
= 39.15 × 10³ Hz
∴ n = 39.15 kHz

Question 53.
Source of sound is placed at one end of a copper bar of length 1 km. Two sounds are heard at the other end at an interval of 2.75 seconds, (speed of sound in air = 330 m/s)
i. Why do we hear two sounds?
ii. Find the velocity of sound in copper.
i. Two sounds are heard because sound travels through air as well as through copper.

ii. In air, t1 = $$\frac {distence}{time}$$ = $$\frac {1000}{330}$$ = 3.03 s
As the time interval is 2.75 seconds and sound travels faster in copper.
∴ In copper, t2 = 3.03 – 2.75 = 0.28 s
∴ velocity of sound in copper = $$\frac {1000}{0.28}$$ = 3571 m/s

Question 54.
If all the persons mentioned in the table below are listening to a match commentary on the same channel at their respective locations positioning at same distance from television, then will they hear the same line of the commentary at same instant of time? Justify your answer.

 Name of a person Location Humidity Aijun Bangalore 65 % Virendra Hyderabad 56% Vikas Delhi 54% Nilesh Mumbai 75%

As the order of humidity for the above locations is Mumbai > Bangalore > Hyderabad > Delhi.
As velocity of sound increases with increase in humidity, the order of velocity of sound at their respective locations is Mumbai > Bangalore > Hyderabad > Delhi.
Hence, the order of persons who would listen the line of commentary first to last is Nilesh, Arjun, Virendra, Vikas.

Question 55.
Speed of sound is greater during day than at night. True or False? Justify your answer.
True. At night, the amount of CO2 in atmosphere increases the density of atmosphere. Since, Speed of sound is inversely proportional to the square root of density. Hence, speed of sound is greater during day than in night.

Question 56.
Case I: During summer (33 °C), Prakash was waiting for a train at the platform, train arrived tt seconds after he heard train’s whistle.
Case II: During winter (19 °C), train arrived t2 seconds after Prakash heard the sound of train’s whistle.
ii. Calculate the velocity of sound in both the cases.
(velocity of sound in air at 0 °C = 330 m/s)
i. Velocity of sound is directly proportional to square root of absolute temperature.
Hence, whistle’s sound will be first heard by Prakash in summer than in winter.
Therefore, the time interval between sound and train reaching Prakash in summer will be more than in winter.
i.e.,t1 > t2

ii. When t = 33 °C
∴ v1 = v0 + 0.61t
= 330 + 0.61 × 33
∴ v1 = 350.13 m/s
When t = 19 °C
v2 = v0 + 0.61t
= 330 + 0.61 × 19
v2 = 341.59 m/s

Question 57.
You are at a large outdoor concert, seated 300 m from speaker system. The concert is also being broadcast live. Consider a listener 5000 km away who receives the broadcast. Who will hear the music first, you or listener and by what time difference? (Speed of light = 3 × 108 m/s and speed of sound in air = 343 m/s)
s1 = 300 m,
v1 = 343 m/s,
∴ t1 = $$\frac {s_1}{v_1}$$ = $$\frac {300}{343}$$ = 0.8746 s
Now,
s2 = 5000 km = 5 × 106 m,
v2 = c = 3 × 108 m/s
∴ t2 = $$\frac {s_2}{c}$$ = $$\frac {5×10^6}{3×10^8}$$ = 0.0167 s
∴ t2 < t1
∴ Listener will hear the music first.
Time difference = t1 – t2
= 0.8746 – 0.0167
= 0.8579 s
The listener will hear the music first, about 0.8579 s before the person present at the concert.

Question 58.
When a source of sound moves towards a stationary observer, then the pitch increases. Give reason.
When a source of sound moves towards a stationary observer, then the increase in pitch is due to actual or apparent change in wavelength. When the source of sound moves towards an observer at rest, waves get compressed and the effective velocity of sound waves relative to source becomes less than the actual velocity. Hence the wavelength of sound waves an decreases which results into increase in pitch.

Question 59.
In the examples given below, state if the wave motion is transverse, longitudinal or a combination of both?

1. Light waves travelling from Sun to Earth.
2. ultrasonic waves in air produced by a vibrating quartz crystal.
3. Waves produced by a motor boat sailing in water.

1. Light waves (from Sun to Earth) are electromagnetic waves which are transverse in nature.
2. Ultrasonic waves in air are basically sound waves of frequency greater than the audible frequencies. Therefore, these waves are longitudinal.
3. The water surface is cut laterally and pushed backwards by the propeller of motor boat. Therefore, the waves produced are a mixture of longitudinal and transverse waves.

Question 60.
Internet my friend
https://hyperphysics.phys-astr.gsu.edu/ hbase/hframe.html

Multiple Choice Questions

Question 1.
Water waves are …………….
(A) longitudinal
(B) transverse
(C) both longitudinal and transverse
(D) neither longitudinal nor transverse
(C) both longitudinal and transverse

Question 2.
Sound travels fastest in ……………..
(A) water
(B) air
(C) steel
(D) kerosene oil
(C) steel

Question 3.
At room temperature, velocity of sound in air at 10 atmospheric pressure and at 1 atmospheric pressure will be in the ratio ……………..
(A) 10 : 1
(B) 1 : 10
(C) 1 : 1
(D) cannot say
(C) 1 : 1

Question 4.
In a gas, velocity of sound varies directly as ………………
(A) square root of isothermal elasticity.
(B) square of isothermal elasticity.
(C) square root of adiabatic elasticity.
(C) square root of adiabatic elasticity.

Question 5.
At a given temperature, velocity of sound in oxygen and in hydrogen has the ratio …………………
(A) 4 : 1
(B) 1 : 4
(C) 1 : 1
(D) 2 : 1
(B) 1 : 4

Question 6.
With decrease in water vapour content in air, velocity of sound …………………..
(A) increases
(B) decreases
(C) remains constant
(D) cannot say
(B) decreases

Question 7.
The temperature at which speed of sound in air becomes double its value at 0 °C is ……………….
(A) 546 °C
(B) 819 °C
(C) 273 °C
(D) 1092 °C
(B) 819 °C

Question 8.
The velocity of sound in air at NTP is 330 m/s. What will be its value when temperature is doubled and pressure is halved?
(A) 330 m/s
(B) 165 m/s
(C) 330 √2 m/s
(D) $$\frac {330}{√2}$$ m/s
(D) $$\frac {330}{√2}$$ m/s

Question 9.
A series of ocean waves, each 5.0 m from crest to crest, moving past the observer at a rate of 2 waves per second have wave velocity
(A) 2.5 m/s
(B) 5.0 m/s
(C) 8.0 m/s
(D) 10.0 m/s
(D) 10.0 m/s

Question 10.
A radio station broadcasts at 760 kHz. What is the wavelength of the station?
(A) 395 m
(B) 790 m
(C) 760 m
(D) 197.5 m
(A) 395 m

Question 11.
If the bulk modulus of water is 2100 MPa, what is the speed of sound in water?
(A) 1450 m/s
(B) 2100 m/s
(C) 0.21 m/s
(D) 21 m/s
(A) 1450 m/s

Question 12.
If speed of sound in air at 0°C is 331 m/s. What will be its value at 35° C?
(A) 331 m/s
(B) 366 m/s
(C) 351.6 m/s
(D) 332 m/s.
(C) 351.6 m/s

Question 13.
For a progressive wave, in the usual notation
(A) v = λT
(B) n = $$\frac {v}{λ}$$
(C) T = λv
(D) λ = $$\frac {1}{n}$$
(B) n = $$\frac {v}{λ}$$

Question 14.
At normal temperature, for an echo to be heard the reflecting surface should be at a minimum distance of ………………. m.
(A) 34.4
(B) 17.2
(C) 10
(D) 20
(B) 17.2

Question 15.
In a transverse wave, are regions of negative displacement.
(A) rarefactions
(B) compressions
(C) crests
(D) troughs
(D) troughs

Question 16.
If pressure of air gets doubled at constant temperature then velocity of sound in air ……………….
(A) gets doubled
(B) remains unchanged
(C) √2 times initial velocity
(D) becomes half
(B) remains unchanged

Question 17.
Wave motion has ……………………
(A) single periodicity.
(B) double periodicity.
(C) only periodicity in space.
(D) only periodicity in time.
(B) double periodicity.

Question 18.
The speed of the mechanical wave depends upon ………………
(A) elastic properties of the medium only.
(B) density of the medium only.
(C) elastic properties and density of the medium
(D) initial speed.
(C) elastic properties and density of the medium

Question 19.
Longitudinal waves CANNOT be …………………
(A) reflected
(B) refracted
(C) scattered
(D) polarised
(D) polarised

Question 20.
Wavelength of the transverse wave is 30 cm. If the particle at some instant has displacement 2 cm, find the displacement of the particle 15 cm away at the same instant.
(A) 2 cm
(B) 17 cm
(C) -2 cm
(D) -17 cm
(C) -2 cm

Question 21.
The wavelength of sound in air is 1.5 m and that in liquid is 2 m. If the velocity of sound in air is 330 m/s, the velocity of sound in liquid is
(A) 330 m/s
(B) 440 m/’s
(C) 495 m/s
(D) 660 m/s
(B) 440 m/’s

Question 22.
The velocity of sound in a gas is 340 m/s at the pressure P, what will be the velocity of the gas when only pressure is doubled and temperature same?
(A) 170 m/s
(B) 243 m/s
(C) 340 m/s
(D) 680 m/s
(C) 340 m/s

Question 23.
Choose the correct statement.
(A) For 1 °C rise in temperature, velocity of sound increases by 0.61 m/s.
(B) For 1 °C rise in temperature, velocity of sound decreases by 0.61 m/s.
(C) For 1 °C rise in temperature, velocity of sound decreases by $$\frac {1}{273}$$ m/s.
(D) For 1 °C rise in temperature, velocity of sound increases by $$\frac {1}{273}$$ m/s.
(A) For 1 °C rise in temperature, velocity of sound increases by 0.61 m/s.

Question 24.
A sound note emitted from a certain source has a velocity of 300 m/s in air and 1050 m/s in water. If the wavelength of sound note in air is 2 m, the wavelength in water is …………
(A) 2 m
(B) 6 m
(C) 7 m
(D) 12 m
(C) 7 m

Question 25.
A thunder clap was heard 6 seconds after a lightening flash was seen. If the speed of sound in air is 340 m/s at the time of observation, the distance of the listener from the thunder clap is ………………
(A) 56.6 m
(B) 346 m
(C) 1020 m
(D) 2040 m
(D) 2040 m

Question 26.
The speed of sound in air at NTP is 330 m/s. The period of sound wave of wavelength 66 cm is …………………
(A) 0.2 s
(B) 0.1
(C) 0.1 × 10-2 s
(D) 0.2 × 10-2 s
(D) 0.2 × 10-2 s

Question 27.
If the velocity of sound in hydrogen is 1248 m/s, the velocity of sound in oxygen is [Given: MO = 32 and MH = 2]
(A) 1248 m/s
(B) 624 m/s
(C) 312 m/s
(D) 300 m/s
(C) 312 m/s

Question 28.
If the source is moving away from the observer, then the apparent frequency …………..
(A) will increase
(B) will remain the same
(C) will be zero
(D) will decrease
(D) will decrease

Question 29.
The working of SONAR is based on …………………
(A) resonance
(B) speed of a star
(C) Doppler effect
(D) speed of rotation of sun
(A) v = $$\sqrt{\frac {m}{T}}$$
(B) v = $$\sqrt{\frac {T}{m}}$$
(C) v = ($$\frac {m}{T}$$)$$\frac {3}{2}$$
(D) v = ($$\frac {T}{m}$$)$$\frac {3}{2}$$
(B) v = $$\sqrt{\frac {T}{m}}$$