Class 6

Balbharti Maharashtra State Board Class 6 English Solutions Chapter 1.2 Who’s the Greatest? Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 English Solutions Chapter 1.2 Who’s the Greatest?

Class 6 English Chapter 1.2 Who’s the Greatest? Textbook Questions and Answers

1. Listen to the stories carefully, as your teacher reads them aloud. Note down the new words, ideas or concepts. Discuss them in the class.

Question 1.
Listen to the stories carefully, as your teacher reads them aloud. Note down the new words, ideas or concepts. Discuss them in the class.

2. Guess the meaning of the following words and phrases:
untold wealth, closest to the Emperor’s heart, grave offence, banish.

Question 1.
Guess the meaning of the following words and phrases:
untold wealth, closest to the Emperor’s heart, grave offence, banish.
Answer:

1. untold wealth: limitless wealth, the magnitude of which is not revealed
2. closest to the Emperor’s heart: dear to the Emperor
3. grave offence: serious mistake
4. banish: send away into exile

3. Say with reasons, whether the following statements are true or false.

Question a.
Akbar wanted to punish the person who pulled his moustache.
Answer:
False. Akbar did tell his courtiers that someone had pulled his moustache. But it was his grandson who had lovingly pulled his moustache and Akbar did not have any intention of punishing him.

Question b.
Akbar thought he was greater than God.
Answer:
False. Akbar did not think so. It was his courtiers who said so in an attempt to praise him for receiving favours.

Question c.
Birbal thought Akbar was greater than God.
Answer:
True. Birbal thought Akbar was greater than God but only at one aspect. Unlike Akbar, God’s kingdom extended everywhere so the Almighty God could not banish anyone from his kingdom.

4. Write a sentence about three of your friends. Each time you should say what your friend cannot do, and yet, pay a compliment to your friend.

Question 1.
Write a sentence about three of your friends. Each time you should say what your friend cannot do, and yet, pay a compliment to your friend.
Answer:

• My friend Raj cannot say no to others as he does not like to hurt others.
• My friend Radha cannot hurt animals as she is concerned about their welfare.
• My friend Sai cannot be rude to others because he is extremely loving and polite.

5. Write a short note on Emperor Akbar.

Question 1.
Write a short note on Emperor Akbar.
Answer:
Emperor Akbar or Akbar the Great is known as one of the greatest rulers in the world – not just because he had a vast empire, a very strong army, untold wealth but because he was a good human being. He cared for his subjects. He had great respect for scholars, writers, poets and artists belonging to different religions. He was a patron of art and culture. The nine gems or ‘nav-ratnas’ in his court were famous which included Birbal who was known for his wit and humour. He was the one who was very dear to Akbar.

6. Convert the stories into dialogues and read the dialogues aloud in the class.

Question 1.
Convert the stories into dialogues and read the dialogues aloud in the class.
(One is done for you.)
Answer:

• Emperor Akbar: (With a serious expression.)
  I have a question for all of you. What should be the punishment for someone who pulls my moustache?
• One Nobleman: Flog him! Give him fifty lashes of the whip.
• Second Nobleman: That’s not enough. Put him in jail without food and water.
• Third Nobleman: Whip him! Beat him up! Fourth Nobleman: Hang him!
• Fifth Nobleman: Cut off his offending hands.
• Akbar: What do you say Birbal?
  What is your opinion?
• Birbal: In my opinion, given of peace to the world, the offender should be given his favourite sweetmeats.
• Courtiers: Raja Birbal, are you out of your mind? Give sweetmeats for such a grave offence?
• Birbal: Yes, who would be so bold as to pull the Emperor’s moustache? Only his own grandson!
  (Akbar burst out laughing as it was exactly what had happened in the morning.)

7. Form pairs and make a ‘pair presentation’ of any one of the two stories. To do so, each person presents only one sentence at a time, and the next one is immediately presented by the partner. Thus, each person in the pair presents alternate sentences without breaking the flow of the narration.

8. Find at least five other Akbar and Birbal stories and share them with your friends. Make a list of the stories collected by the entire class. Write your list in alphabetical order.

9. Visit a library. Find the stories of:

• Mulla Nasiruddin
• Gopal Bhand
• Tenali Raman

Share them in the class.

Class 6 English Chapter 1.2 Who’s the Greatest? Additional Important Questions and Answers

Answer in one sentence.

Question 1.
Why is Emperor Akbar or Akbar the Great known as one of the greatest rulers in the world?
Answer:
Emperor Akbar or Akbar the Great is known as one of the greatest rulers in the world, not just because he had a vast empire, a very strong army, untold wealth, but because he was a good human being.

Question 2.
Give two examples to show that Akbar was an ideal ruler.
Answer:

1. Akbar cared for his subjects.
2. He had great respect for scholars, writers, poets and artists belonging to different religions.

Question 3.
Who did Akbar have great respect for?
Answer:
Akbar had great respect for scholars, writers, poets and artists belonging to different religious.

Question 4.
Which question posed by Akbar stunned the Emperor’s court? Why?
Answer:
The question, “What should be the punishment for someone who pulls my moustache?” stunned Akbar’s court as it was unheard of.

Question 5.
Write any one punishment suggested by any one nobleman.
Answer:
One nobleman suggested that the person who pulled the Emperor’s moustache should be flogged with fifty lashes of the whip.

Question 6.
What was Birbal’s suggestion regarding punishing the offender?
Answer:
Birbal suggested that the offender should be given his favourite sweetmeats.

Question 7.
What explanation did Birbal offer for his choice of punishment?
Answer:
Birbal explained that only his own grandson would be so bold to pull the Emperor’s moustache and so giving his favourite sweetmeats would be the best punishment.

Question 8.
Why did the courtiers compete with each other in praising Akbar?
Answer:
The courtiers competed with each other in praising Akbar as they wanted to get some favours from him.

Question 9.
What dilemma did the courtiers face?
Answer:
When the courtiers praised Akbar and said that he was greater than God Almighty, Akbar asked them to prove it or face punishment.

Question 10.
What was the one thing according to Birbal which Akbar could do but God Almighty could not?
Answer:
According to Birbal when Akbar wanted to punish someone, he could banish that person out of his kingdom, but as God’s kingdom extended everywhere, the Almighty couldn’t banish anyone from his kingdom.

Reading Skills, Vocabulary and Grammar

Read the following extract and complete the activities that follow.

Question 1.
State whether the following statements are true or false.
a. Akbar was happy to hear the praises from his courtiers.
b. Akbar was angry with Birbal’s response.
Answer:
a. False
b. False

Question 2.
What information did Akbar want?
Answer:
Akbar wanted to know if the courtiers had found an answer to his question.

Question 3.
Why could God not banish anyone from his kingdom?
Answer:
God couldn’t banish anyone from his kingdom because God’s kingdom extended everywhere.

Question 4.
Why did Akbar’s face lighten up with a smile?
Answer:
Akbar’s face lightened up with a smile because Birbal had given a clever reply.

Question 5.
Why did Akbar forgive the courtiers for their stupidity?
Answer:
Akbar was so pleased with the answer given by Birbal that he forgave the courtiers for their stupidity.

Question 6.
Find the odd word:
look, royal, good, proper
Answer:
look, The rest are adjectives.

Question 7.
Complete the analogy:
Answer:
prove: proof: punish: punishment

Question 8.
Everyone was curious to see what would happen next. (State the word class of the underlined word.)
Answer:
next: adverb

Question 9.
The Almighty cannot banish anyone from his kingdom. (Add a question tag)
Answer:
The Almighty cannot banish anyone from his kingdom, can he?

Question 10.
Do you believe in false praise? Elaborate.
Answer:
No, I don’t. Appreciating people for their good qualities is a good thing but resorting to false praise for receiving favours or for some ulterior motive is definitely something which we should refrain from.

Language Study

Do as directed.

Question 1.
You are the greatest of the kings. (Underline the adjective)
Answer:
greatest.

Question 2.
Put him in jail without food and water. (State the types of nouns)
Answer:
food, water – Material noun.

Question 3.
He was an patron of art and culture. (Correct the article)
Answer:
He was a patron of art and culture.

Question 4.
I believe you. ( Begin the sentence with ‘you are )
Answer:
You are believed (by me).

Question 5.
Flag him ! (State the type of sentence)
Answer:
Exclamatory sentence.

Question 6.
Akbar looked at Birbal thoughtfully (State the part of speech of the underlined word)
Answer:
thoughtfully – Adverb.

Make sentences using the following phrases.

1. to have respect: I have great respect for my teachers who are my friends and my guide.
2. to come up with: He came up with the most silly excuse.
3. to be stunned: The whole world was stunned by the news .
4. to offer an explanation: He realised his mistake and offered an explanation for them.
5. to have an advantage: The other team in the game had an advantage because they were highly experienced.

Complete the following table.

Noun	Adjective	Verb
care	careful	care
belief	believable	believe
competition	competitive	compete
punishment	punishable	punish

Give the antonyms by providing appropriate suffixes.

1. interesting × uninteresting
2. human × inhuman
3. pleased × displeased
4. advantage × disadvantage
5. proper × improper

Give one word for:

1. very great in area or size: vast
2. to beat someone hard with a whip: flog
3. to be disturbed: agitated
4. lack of cleverness: stupidity

Did you Know?

Birbal stories are very famous and popular in India among all ages of people. They are also known as Akbar-Birbal stories. Akbar, the Great, the Mughal Emperor in India, ruled from 1560 to 1605. He himself was illeterate but he invited several learned people in his court. Among these, nine people were very famous and were known as Nav-ratnas. Birbal was the favourite of Akbar, because of his wisdom, wit and subtle humour.

Who’s the Greatest? Summary in English

Who’s the Greatest? is an interesting lesson which narrates two of the very popular Akbar and Birbal stories. Akbar would always pose interesting questions and problems in his court and Birbal, one of his nine gems or ‘nav-ratnas’ never failed to come up with an answer displaying his wit and humour.

In this lesson, one of the stories talks about Akbar’s question to his courtiers:
“What should be the punishment for someone who pulls my moustache?”
While everyone called for strict actions for the grave offence, Birbal smilingly suggested that Akbar should give the offender his favourite sweetmeats. After all he said, who would be so bold to pull the Emperor’s moustache other than his own grandson?
The next story is about the challenge Akbar posed to his courtiers who showered him with false praises and called him greater than the God Almighty.
He told the courtiers to tell him atleast one thing he could do but God Almighty would not be able to do.
Here Birbal came to the courtier’s rescue. He said:
“When you want to punish someone, you can banish that person – you can throw him out of your kingdom. But God’s kingdom extends everywhere. The Almighty cannot banish anyone from his kingdom.” Akbar was pleased with the answer.
The humour and wit in the Akbar and Birbal stories are the reasons for their popularity.

Introduction:

‘Who’s the Greatest’ narrates Akbar and Birbal’s stories which reflect Birbal’s wit, humour and intelligence.

Glossary:

1. vast (adj) – very great in area or size
2. empire (n) – a large area ruled by an emperor or supreme authority
3. scholars (n) – learned persons
4. patrons (n) – a person supporting something. Here it is art and culture
5. pose (v) – present a question
6. generations (n) – all the people born in the same period
7. agitated (adj) – angry, disturbed.
8. courtiers (n) – attendants at the court
9. offender (n) – one who commits an illegal act
10. opportunity (n) – circumstances which ensure that something can be done
11. displeasure (n) – annoyance
12. banish (v) – send away into exile
13. advantage (n) – something which provides one a favourable position

Balbharti Maharashtra State Board Class 6 English Solutions Chapter 1.1 Don’t Give Up! Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 English Solutions Chapter 1.1 Don’t Give Up!

Class 6 English Chapter 1.1 Don’t Give Up! Textbook Questions and Answers

1. Have you ever given up on something good? Share your story.

Question 1.
Have you ever given up on something good? Share your story.
Answer:
I was a very good cricketer. But on a couple of occasions, I got a feeling that my team failed due to my poor performance. I stopped pursuing the game, but today I regret my decision. I realised very late that: ‘A quitter never wins and a winner never quits’.

2. Your friend fell down learning to ride a bicycle and now has given it up altogether. What do you think will be the poet’s advice?

Question 1.
Your friend fell down learning to ride a bicycle and now has given it up altogether. What do you think will be the poet’s advice?
Answer:
‘Rise each time you fall, never give up’ would be the advice the poet would give my friend. While riding a bicycle or acquiring any new skills, we are bound to fall or face disappointments. The poet would advise him to be patient and rise stronger and achieve what he has set out to achieve with determination and resilience.

Class 6 English Chapter 1.1 Don’t Give Up! Additional Important Questions and Answers

Answer the following questions.

Question 1.
What should we not do if we have tried but not won?
Answer:
If we have tried but not won, we should never stop for crying or feel dejected about the same.

Question 2.
Name two elements of nature mentioned in the poem which display determination and strength.
Answer:
‘Young birds’ and the ‘oak tree’.

Question 3.
Pick out two describing words used in the poem.
Answer:
Young, sturdy

Question 4.
Circle the odd word. great good patient (blast)
Answer:
Blast, the rest are describing words.

Question 5.
Name any one personality from the pages of history who didn’t give up till he succeeded. Justify your answer.
Answer:
Our Father of the Nation, Mahatma Gandhi, did not give up or buckle under pressure in our struggle for independence. Finally, due to his relentless efforts and determination, we became free from the British rule and became an independent nation.

Question 6.
Explain the line: “If by easy work you beat, who the more will prize you?”
Answer:
The above lines from the poem ‘Don’t Give Up’ written by Phoebe Cary convey the message that if success comes to us easily it will not be considered as our achievement. Rising above challenges and failures, and emerging a winner is true success, according to the poet.

Reading Skills, Poetic Device

Read the following stanza and answer the questions that follow.

Question 1.
Pre-reading activity:
Complete the web diagram with action words from the poem.
Answer:

Question 2.
What is the central idea of the poem?
Answer:
The central idea of the poem is that we should never give up and be patient in the face of failures as we continue to keep trying. Failures are bound to occur. We should not lose heart and stop trying but gain victory from defeat with our willpower and our determination.

Question 3.
According to the poet, how has the great and good been done in this world?
Answer:
According to the poet, all that’s great and good is done just by trying, with patience and determination till we achieve our goal.

Question 4.
What happens to the young birds while they try to fly?
Answer:
The young birds fall as they try to fly.

Question 5.
Pick out lines to prove that the oak has survived many blows of stormy winds.
Answer:
‘She has risen again and grown, Loftier and prouder’.

Question 6.
Pick out a contraction from the extract.
Answer:
You’ve (It stands for you have)

Question 7.
Do you agree with the maxim: ‘Try, try, till you succeed’?
Answer:
Yes. I agree with the maxim: ‘Try, try till you succeed’. We should remember that ‘A quitter never wins and winner never quits’.
People like Mahatma Gandhi, Sachin Tendulkar, A.P.J. Abdul Kalam and others have proved the above maxim to be right, with their life and work.
We should remember that disappointments and failures are bound to occur in our journey to succeed, but we should never lose heart. We should keep trying patiently till we accomplish our goal.

Poetic Device/Appreciation:

Question 1.
Find the meaning of the following expressions.
Answer:

1. All that’s great and good: All the great achievements and accomplishments we see around us.
2. Has known many a blast: The tree has survived many blows of stormy weather.
3. The test that tries: A situation which is challenging, and which tests our endurance, our resilience and our willpower.

Poetic Devices:

Question 1.
Pick out two pairs of rhyming words from the poem.
Answer:

• won – done
• stronger – longer
• known-grown

Question 2.
Name the rhyme scheme used in the first four lines of the poem.
Answer:
abab

Question 3.
Name and explain the figure of speech used in the line.
‘That’s the test that tries you’.
Answer:
The figure of speech used in the above line is Alliteration as the sound of the alphabet’t’ is repeated for a better poetic effect.

Student’s Activity:

Question 1.
Find real life stories of some indians, abled and disabled, who have beaten all odds to become great achievers. You can also make a power point presentation with the help of your teacher.

Don’t Give Up! Summary in English

‘Don’t Give Up’ written by Phoebe Cary has a beautiful message for each one of us. The poet advises us never to be disheartened or dejected by failures. We are reminded that all the great and good things in this world is done just by patience and relentless efforts of the concerned people.

The poet gives the example of young birds who in their initial flights, fall but rise higher and stronger each time, thus proving that resilience and determination can help scale great heights.

The sturdy oak too has withstood challenges of time before rising up taller, stronger and prouder. Our achievements and our accomplishments may not be celebrated by others if it had come to us easily. But despite all odds, overcoming all challenges, rising above defeats when we achieve our goal and gain victory, that will be our true test, our real victory.

Introduction:

‘Don’t Give Up’ written by Phoebe Cary conveys the message that failures should not discourage us from achieving what we have set out to do. In a nutshell, the poet is conveying the message that we should never quit, however hard the situation and emerge a winner.

Glossary:

1. patient (adj) – a person with calm endurance
2. sturdy (adj) – strong
3. oak (n) – a deciduous forest tree
4. victory (n) – success achieved
5. test that tries (phr) – something done to discover/test our ability
6. give up (phr) – lose heart and stop trying
7. has known many a blast (phr) – has survived many blows of stormy winds
8. loftier (adj) – taller and stronger
9. you beat (phr) – you win (here)
10. resilience (n) – able to recover quickly from difficult conditions.

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 12 Simple Machines Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 Science Solutions Chapter 12 Simple Machines

Class 6 Science Chapter 12 Simple Machines Textbook Questions and Answers

1. Classify the following as a lever, a pulley and an inclined plane:
(A wedge, a needle, a staircase, a slide, the wheel of a flagpole, nutcrackers, scissors, an opener, an axe, a crane, a knife)

Question a.
Classify the following as a lever, a pulley and an inclined plane:
(A wedge, a needle, a staircase, a slide, the wheel of a flagpole, nutcrackers, scissors, an opener, an axe, a crane, a knife)
Answer:

Inclined plane	Pulley	Lever
Wedge	Wheel of flagpole	Nutcracker
Needle	Crane	Scissors
Staircase		Opener
Slide
Axe
Knife.

2. Fill in the blanks using the proper word and complete the statements.

Question a.
The ………….. in the centre, the ………….. on one side and the on the ………….. other side make a lever of the first order.
Answer:
Fulcrum, load and effort

Question b.
The ………….. in the centre, the ………….. on one side and the ………….. on the other side make a lever of the second order.
Answer:
Load, fulcrum, effort

Question c.
The ………….. in the centre, the ………….. on one side and the ………….. on the other side make a lever of the third order.
Answer:
Effort, fulcrum, load

3. Which machines will you use to do the following work? Write their types.

Question a.
To remove the lid of a tin. Opener Lever of the second order
Answer:

• Work: To remove the lid of a tin.
• Machine: Opener
• Machine: Lever of the second order

Question b.
To lift bricks to the top of a tall building Crane Complex machine
Answer:

• Work: To lift bricks to the top of a tall building
• Machine: Crane
• Machine: Complex machine

Question c.
To cut vegetable Knife Wedge – Simple machine
Answer:

• Work: To cut vegetable
• Machine: Knife
• Machine: Wedge – Simple machine

Question d.
To draw water from a well Pulley Simple machine
Answer:

• Work: To draw water from a well
• Machine: Pulley
• Machine: Simple machine

Question e.
To hold a papad for roasting it. A pair of tongs Lever of the third order
Answer:

• Work: To hold a papad for roasting it.
• Machine: A pair of tongs
• Machine: Lever of the third order

4. Write the answers to the following questions in your own words. 

Question a.
What is meant by a simple machine?
Answer:

1. Machines which have only one or two parts and a simple and easy structure are simple machines.
2. Example: the bottle opener, nail cutter.
3. Simple machines can be handled easily.
4. We use many simple machines in our day to day life.

Question b.
Mention the advantages of using a machine.
Answer:

1. Machines, simple or complex, are used to get more work done in less time and with less effort.
2. Machines are used to accomplish certain tasks more easily.
3. Use of simple or complex machines depends upon the task to be carried out and the time and the efforts required to do it.

Question c.
What is meant by a complex machine?
Answer:

1. Complex machines have many parts which carry out many processes for completing a task.
2. For this purpose the parts are joined to one another.
3. Therefore, these machines are called complex machines.
4. Some of the parts of such complex machines are actually simple machines.
5. The structure of complex machine is complicated.

Question d.
What is a lever? How is the order of the lever determined?
Answer:

1. Lever is a simple machine made up of 3 parts: Load, effort and fulcrum.
2. Order of the lever are determined on the position of the effort, the fulcrum and the load.

5. Why is this so?

Question a.
Traveller’s bags have wheels.
Answer:

1. Combination of wheel and axle is a simple machine.
2. When the axle starts rotating due to force applied, the wheel fitted to it also starts rotating.
3. This makes easier for travellers to carry heavy load.
4. Instead of lifting heavy bag, to drawing it on wheels require less energy. Therefore, traveller’s bag have wheels.

Question b.
Machines have to be maintained.
Answer:

1. Parts of machines rub against one another when they are used.
2. Soiled, dusty parts create more friction. Some parts are affected by the weather, rust and corrosion.
3. Machines get damaged or become useless due to such wear and tear. Hence to avoid this, machines should be maintained properly to keep them in good working condition.

Question c.
A bicycle is said to be a complex machine.
Answer:

1. Bicycle has a complicated structure.
2. Bicycle has many parts which carry out many processes for completing a task.
3. Many parts of bicycle such as pedals, wheels, axle, handle are actually simple machines.
4. The parts of a bicycle are joined to one another – making it a complex machine.

6. Name the levers mentioned in the following passage. Identify the fulcrum, load and effort of each and say which type of lever it is.

Ravi and Savita sit on a sea-saw in a garden. In the mean time, a gardener is trimming trees in the garden. He puts the leaves and other garbage in the wheelbarrow. Later, Ravi gets thirsty and he buys lemon sherbet. The sherbet seller cuts the lemon and squeezes it using a lemon squeezer. He puts small pieces of ice in the glass with the help of the tongs.

Question a.
Name the levers mentioned in the following passage. Identify the fulcrum, load and effort of each and say which type of lever it is.

Ravi and Savita sit on a sea-saw in a garden. In the mean time, a gardener is trimming trees in the garden. He puts the leaves and other garbage in the wheelbarrow. Later, Ravi gets thirsty and he buys lemon sherbet. The sherbet seller cuts the lemon and squeezes it using a lemon squeezer. He puts small pieces of ice in the glass with the help of the tongs.
Answer:
Levers:

1. See – saw – lever of the first order.
   Load – fulcrum – effort.
2. Wheelbarrow – lever of the second order.
   Fulcrum – load – effort.
3. Lemon squeezers – lever of the second order.
   Fulcrum – load – effort.
4. Tongs – lever of the third order.
   Fulcrum – effort – load.

Activity:

Question 1.
Make a list of the various machines used in your home and neighborhood and write their types.

Question 2.
Go to a bicycle repair shop, observe how a bicycle is repaired, and note down the information.

Class 6 Science Chapter 12 Simple Machines Important Questions and Answers

Fill in the blanks.

Question 1.
Simple machines can be handled ………….. .
Answer:
easily

Question 2.
The structure of complex machine is ………….. .
Answer:
complicated

Question 3.
The more gradual the the ………….. lesser is the we bear. But, such an inclined plane is ………….. .
Answer:
slope, weight, longer

Question 4.
The steeper the ………….. , the ………….. is the inclined plane. But we have to bear a …………. weight.
Answer:
slope, shorter, greater

Question 5.
A screw is like a rolled up inclined plane made of an ………….. strip.
Answer:
iron

Question 6.
A wedge is used for ………… an object into two pieces or to ………….. the objects stuck together.
Answer:
breaking, separate

Question 7.
A farmer uses a strong …………. to remove the big stone bogged down in the farm.
Answer:
crow-bar

Question 8.
A device with a grooved wheel and thread designed to lift weights is called a …………. .
Answer:
pulley

Question 9.
When we use a pulley, force is applied in the downward direction for lifting the weight in an …………. direction.
Answer:
upward

Question 10.
Combination of an axle and a wheel is a …………. machine.
Answer:
simple

Question 11.
A needle and a nail are also kind of …………. .
Answer:
wedge

Question 12.
Machines are covered when not in use to prevent …………. settling on them.
Answer:
dust

Question 13.
In Archimedes’ screw, the pipe was placed at an angle of …………. with one end inside the …………. and the rod resting on a …………. .
Answer:
45°, water, flat surface.

Match the columns:

Question 1.

Column ‘A’	Column ‘B’
1. Pair of Scissors	a. Third order of lever
2. Tongs	b. Second order of lever
3. Opener	c. First order of lever

Answer:

Column ‘A’	Column ‘B’
1. Pair of Scissors	c. First order of lever
2. Tongs	a. Third order of lever
3. Opener	b. Second order of lever

Question 2.

Column ‘A’	Column ‘B’
1. Inclined plane	a. Needle
2. Pulley	b. Screw
3. Wedge	c. Crane

Answer:

Column ‘A’	Column ‘B’
1. Inclined plane	b. Screw
2. Pulley	c. Crane
3. Wedge	a. Needle

State whether the following statements are ‘true’ or ‘false’.

Question 1.
Lever helps big vehicle to climb up and down the mountain easily.
Answer:
False

Question 2.
Combination of wheel and axle is a simple machine.
Answer:
True

Question 3.
In pulley, force can be applied in upward direction.
Answer:
False

Question 4.
Screw is an example of wedge.
Answer:
False

Question 5.
In Archimedes screw, the rod rests on flat surface.
Answer:
True

Question 6.
A slanting plank is used to lift a weight.
Answer:
True

Question 7.
A winding road or ghat is an example of lever of first order.
Answer:
False

Answer the following questions in one sentence.

Question 1.
What is a machine?
Answer:
Devices which are used to get more work done in less time and less effort are called machines.

Question 2.
What is a simple machine?
Answer:
Machines which have only one or two parts and a simple and easy structure are called simple machines.

Question 3.
What is a complex machine?
Answer:
Some machines have many parts and they carry out many processes for completing a task. For this purpose, the parts are joined to each other. They are called complex machines.

Question 4.
List the properties of simple machines.
Answer:
Properties of simple machine are:

1. They are made up of only one or two parts.
2. They have a simple and easy structure.
3. They can be handled easily.
4. There are less chances of simple machines breaking down or getting damaged.

Question 5.
List properties of complex machines.
Answer:
Properties of complex machine are:

1. These machines have many parts to carry out many processes.
2. The parts are joined to one another.
3. The structure of complex machines is complicated.
4. Some parts of complex machines are actually simple machines.

Question 6.
What is an inclined plane?
Answer:
A slanting plank which is used to lift a weight on which we bear less weight and lifting becomes easier is an inclined plane.

Question 7.
What is a screw?
Answer:
A screw is like a rolled up inclined plane made up of iron strip.

Question 8.
What is a wedge?
Answer:
A wedge is used for breaking an object into two pieces or to separate objects stuck together.

Question 9.
State examples of wedges.
Answer:
An axle, a knife, a chisel, a needle and a nail are different kinds of wedges.

Question 10.
What is a lever?
Answer:
A lever is a machine made up of 3 parts: effort, load and fulcrum.

Question 11.
What is a fulcrum?
Answer:
The support at which the rod of a lever is rested is called fulcrum of a lever. The lever rotates about the fulcrum.

Question 12.
What is a load?
Answer:
The weight lifted by a lever or the force against which the lever acts is called a load.

Question 13.
What is a load arm?
Answer:
The arm of the lever from the fulcrum to the load is called a load arm.

Question 14.
What is an effort?
Answer:
The force applied on the other end of the rod to lift the load is called an effort.

Question 15.
What is an effort arm?
Answer:
The part of the lever from the fulcrum to the effort is called an effort arm.

Question 16.
What is lever of the first order?
Answer:
The fulcrum is in the centre, the load is at one end while effort is at other end.

Question 17.
What is lever of the second order?
Answer:
The load is in the centre, the fulcrum on one side, and the effort on the other side.

Question 18.
What is lever of the third order?
Answer:
The effort is in the centre, the fulcrum on one side, and the load on the other side.

Question 19.
What is a pulley?
Answer:
A pulley is a device with a grooved wheel and thread designed to lift weights.

Question 2.
How does a pulley help us?
Answer:
If we use a pulley, force can be applied in the downward direction for lifting the weight in an upward direction. It is convenient and easy.

Give scientific reasons:

Question 1.
We use many simple machines in our day-to-day life.
Answer:
Simple machines can be handled easily and there are less chances of these machines breaking down or getting damaged. Hence, we use many simple machines in our day-to-day life.

Question 2.
Less force is required to fit a screw than to hammer a nail.
Answer:

1. A screw is like a rolled-up inclined plane of an iron strip.
2. When a screw is fitted in wood it goes in as if it is going down an inclined plane.
3. Therefore, less force is required to fit a screw than hammer a nail.

Question 3.
Big vehicles easily climb up and down the mountains than a pathway.
Answer:
A winding road or ghat that goes up a mountain is like an inclined plane wrapped around the mountain. It helps big vehicles to climb, up and down the mountain easily.

Question 4.
Oil or lubricant is released between parts of machine.
Answer:
Oil or lubricant is released between parts that rub against each other so that there is less friction between them and wearing is reduced.

Question 5.
Machines are covered when not in use.
Answer:
Machines are covered when not in use to prevent dust settling on them.

Question 6.
How are machines protected from the effect of weather?
Answer:
To prevent the effect of weather, metallic parts in a machine are painted externally and the machines are always kept dry.

Draw the neat and labelled diagram of following:

Question 1.
The screw as an inclined plane.
Answer:

Question 2.
Archimedes’ screw
Answer:

Observe the following diagram and identify the order of lever.

Question 1.
Removing the lid.
Answer:

Question 2.
Picking up an object.
Answer:

Question 3.
Lifting a paper weight.

Answer:

1. Lever of the second order
2. lever of third order
3. Level of first order.

Answer each of the question in brief:

Question 1.
With the help of the diagram explain lever of the 1st, 2nd, 3rd order.
Answer:
1. Lever of the First order: The fulcrum is in the centre, the load is at one end, while the effort is at the other end. e.g. scissors

2. Lever of the Second order: The load is in the centre, the fulcrum on one side, and the effort on the other side. e.g. lid opener

3. Lever of the Third order: The effort is in the centre, the fulcrum on one side, and the load on the other side. e.g. Tongs

Question 2.
How can machines be maintained?
Answer:

1. To maintain machines, all its parts are wiped clean.
2. Oil or lubricant is released between parts that rub against each other.
3. Machines are covered, painted externally and always kept dry.

Question 3.
What is an inclined plane? Explain longer and shorter inclined plane.
Answer:

1. A slanting plank used to lift a weight, is called an inclined plane. Because of inclined plane we will experience less weight and weight lifting become easier.
2. Longer inclined plane: When the inclined plane is longer, the slope is more gradual and lesser is the weight we bear.
3. Shorter inclined plane: When the inclined plane is shorter, the slope is steeper and greater is the weight we bear.

Question 6.
Explain the working of a giant wheel.
Answer:

1. The giant wheel is fitted to a rod at its centre. This rod is called an axle.
2. When the axle starts rotating with the help of electricity the wheel fitted to it starts rotating.
3. This combination of an axle and a wheel is a simple machine.

Observe and discuss:

Question 1.
Name the devices and discuss how they help.

Answer:

1. Needle and thread – Stitching of clothes
2. Wheelbarrow – To carry materials.
3. Opener – To open the lids of bottles.
4. Pulley – To lift bucket
5. Nail cutter – To cut nails
6. Axe – To cut wood into small pieces

Can you tell?

Question 1.
Observe the machines shown in the following pictures. For what purposes are they used? Can you name some other machines of this kind?

Answer:

1. Mixer grinder – To grind the foodstuffs
2. Scooter – To ride and reach places
3. Bicycle – To ride and reach places
4. Sewing machine – To stitch clothes
5. Wheel chair – Specially designed for handicapped patients to move around.

Question 2.
Compare the pathway and a road, available to climb the mountain, the time and strength and your convenience, required to reach the mountain top.
Answer:
We can reach the mountain top by climbing the pathway early than by the road. The time required is less but the strength required is more. The road is easy to walk and more time consuming.

Question 3.
If the point of a needle or the edge of a knife become blunt, then the needle does not penetrate the cloth and the knife does not cut into the fruit. Why is this so?
Answer:
The tip of the needle or the edge of a knife becomes blunt due to regular use. Both the knife and the needle lose their sharpness.

Use your brain power!

Question 1.
Which task can be done using a lever?
Answer:
Task such as using a nut cracker, cutting paper with scissors, can be done using a lever.

Question 2.
Some machines we use in our day to day life are shown in picture. What is the type in each of these?

Answer:

• Wheelbarrow – Lever of the third order
• Pair of tongs – Lever of the first order
• See – saw – Lever of the first
• order Cutter – Lever of the second lever
• Pair of Scissors – Lever of the first order.

Question 3.
When the pedal of the bicycle is rotating, the wheel starts rotating. How does this happen?
Answer:
Pedals of the bicycle are connected to the wheels through the axle, when the axle starts rotating, the wheels also start rotating.

Question 4.
Examples of pulley.
Answer:

1. A simple pulley is used to hoist a flag, to draw water from a well.
2. The crane which is used to lift heavy loads is an example of application of pulleys and levers working together.

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 13 Sound Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 Science Solutions Chapter 13 Sound

Class 6 Science Chapter 13 Sound Textbook Questions and Answers

1. Fill in the blanks with the proper words.

Question a.
The propagation of sound does not occur through a ………….. .
Answer:
vacuum

Question b.
Noise pollution is a …………… issue.
Answer:
social/serious

Question c.
The sound which is disagreeable to our ears is called …………… .
Answer:
noise

Question d.
Noise has adverse effects on our …………….. .
Answer:
health

2. What should we do?

Question a.
The silencer of a motorcycle is broken.
Answer:

1. If the silencer of a motorcycle is broken, vehicle should be immediately taken to the garage for repair.
2. If silencer is not maintained properly, it will continue making loud noise on the road while in motion, resulting in increasing noise pollution.

Question b.
A factory in the surrounding is producing continuous loud noise.
Answer:
Factories should be located at a proper distance away from residential areas. Authorities should be contacted who will control the decibel level.

3. Write the answers in your own words.

Question a.
What is meant by vibration?
Answer:
Vibration of an object is necessary for the production of sound. As long as the object vibrates, the sound is heard. When the vibration stops, the sound also stops.

Question b.
Explain with the help of practical examples how sound is propagated through solids.

Answer:

1. Singing
2. Chirping of birds
3. Bursting of crackers
4. Whispering
5. Whistling
6. Flute
7. Honking
8. Dog barking

Question c.
What is meant by noise pollution?
Answer:
Continuous noise which has ill effects is called noise pollution.

Question d.
What measures will you take to control noise pollution?
Answer:
Measures for preventing noise pollution:

1. As far as possible, we should avoid blowing horns.
2. The volume of the TV or radio in the house should be restricted to those watching the programmes.
3. Vehicles should be maintained properly to reduce the unnecessary sounds they produce.
4. Factories, airports, railway stations and bus stands should be located at the proper distance away from residential area.
5. Planting of trees helps reduce noise as trees act as a natural barrier.

4. Complete the table.

Question a.

Answer:

Nature of sound	Unpleasant	Pleasant
1. Speaking		✓
2. Whispering		✓
3. Aeroplane Sounds	✓
4. Horns of Vehicles	✓
5. Railway Engine	✓
6. Rustling of leaves		✓
7. Neighing of a horse	✓
8. Ticking of a clock		✓

Project:

Question 1.
Prepare a list of the harsh sounds mheard near your house. Write about those sounds which produce noise pollution.

Question 2.
Collect information about places where loud noise is prohibited and discuss why it is so.

Class 6 Science Chapter 13 Sound Important Questions and Answers

Fill in the blanks:

Question 1.
Some sounds are ……………… and are heard easily.
Answer:
loud

Question 2.
Some sounds are very ……………… and cannot be heard unless we listen attentively.
Answer:
soft

Question 3.
As long as the object ……………… the sound is heard.
Answer:
vibrates

Question 4.
When the vibration ……………… the sound also stops.
Answer:
stops

Question 5.
The intensity of sound is measured in a unit called ……………… .
Answer:
decibels(dB)

Question 6.
The voice box is located in our ……………… .
Answer:
throat

Question 7.
Sound travels in the form of ……………… through air, water and ……………. .
Answer:
waves, solids

Question 8.
The sound is propagated more clearly through a ……………… than through air.
Answer:
solid

Question 9.
Transmission of sound occurs at a different ……………… through different mediums.
Answer:
speed

Question 10.
Continuous noise which may have ill effects, is called noise ……………… .
Answer:
pollution

Question 11.
Some of the sounds that we enjoy can be a ……………… for others.
Answer:
nuisance

Question 12.
The vibration of an object is necessary for the ……………… of sound.
Answer:
production

Answer in one sentence.

Question 1.
List characteristics of sound.
Answer:
Sounds are soft, loud, pleasant and unpleasant.

Question 2.
What do you mean by unpleasant sounds?
Answer:
The sounds by which we get annoyed are called unpleasant sounds.

Question 3.
What do you mean by loud and soft sounds?
Answer:
The sounds which are heard easily, are loud sounds and the sounds which cannot be heard unless we listen attentively, are soft sounds.

Question 4.
Which movement is exhibited by diaphragm of a speaker and a tabla?
Answer:
Diaphragm of a speaker and a tabla exhibit rapid oscillatory motion which gives rise to vibrations.

Question 6.
What is source of the sound?
Answer:
The object due to which sound is produced is called the source of the sound.

Question 7.
What is acoustics?
Answer:
The science of sound, resonance, production, propagation and effects of sound is called acoustics.

Question 8.
What produces sound in living beings?
Answer:
The vibration of the vocal chords in our larynx or voice box produces sound.

Question 9.
On what does quality of sound depend?
Answer:
Quality of sound produced in the larynx depends upon the tautness of the vocal chords.

Question 10.
How is sound propagated?
Answer:
The sound is propagated in the form of waves through air, water or through a solid.

Question 11.
Why is sound heard more clearly through solids?
Answer:
Transmission of sound occurs at a different speed through different mediums. Transmission of sound is faster through a solid than through a liquid and gas.

Question 12.
What is noise?
Answer:
A loud sound is harsh to ears. Such sounds produce noise.

Question 13.
List the effects of very loud or continuous noise on the people.
Answer:

1. Very loud or continuous noise can cause hearing impairment.
2. This can even lead to deafness.
3. It also causes restlessness, irritability and mental exhaustion.

Question 14.
What is noise pollution?
Answer:
Continuous noise which has ill effects is called noise pollution.

Question 15.
How can we prevent noise pollution with respect to watching TV?
Answer:
The volume of the TV or radio in the house should be restricted to those watching the programmes.

Explain the terms.

Question 1.
Propagation of sound:
Answer:
Sound is said to be propagated when sound waves spread in all directions from a source of sound.

Question 2.
Medium of propagation of sound:
Answer:
The substance around a source of sound through which sound waves spread is called the medium of propagation of sound.

Question 3.
Which sounds do you hear during the recess in the school?
Answer:
During the recess in the school, we hear.

1. laughing
2. students running
3. talking loudly
4. ringing of the bell
5. stamping on the staircase
6. shouting

Question 4.
When there is silence in the classroom, close your eyes and sit quietly. Which sounds in your surroundings can you hear now?
Answer:

1. Loud: Laughing, running, talking, horn of cars, marriage procession, school band, teacher’s voice in next classroom.
2. Pleasant: P.T. teacher’s whistle, chirping of birds.
3. Unpleasant: Shouting, bell ringing, stamping on staircase, dog barking, horns of vehicles.

Question 5.
When a song is being played on a radio or a music system in the house, place your hand on its speaker. What do you feel? Put off the music. What do you feel now?
Answer:

1. When a hand is placed on the speakers of the music system, we feel vibrations on the hand.
2. When music is put off, we don’t feel any vibrations on the hand.

Question 6.
When a metal dish falls on the floor; it makes a loud noise. What do we do to stop the noise? What is the effect of that action?
Answer:
To stop the noise of metal dish falling on the floor, quickly put hand on the dish. Vibrations of the metal dish are stopped and the noise stops.

Question 7.
What is it that vibrates when the sounds of sitar, bell, water tap, and breaking of a saucer, etc. are produced?
Answer:
Strings of the sitar, tongs of the bell, water drops hitting the floor of the basin, pieces of saucers that hit the ground vibrate to produce the sounds.

Question 8.
Take a pot full of water. Strike it lightly on the rim. What do you see? Why are waves formed on the water in the pot?
Answer:

1. We see ripples on the water.
2. When we strike the rim of the pot, our striking causes vibrations. These vibrations are transferred or moved from the pot to the water. Hence, water waves/ripples are seen on the water in the pot.

Question 9.
On rubbing balloon filled with water and another filled with air, of which balloon do we hear a clear or sound?
Answer:
We hear a clearer sound of the water balloon.

Question 10.
If a bell is rung in a vacuum container, will its sound be heard outside?
Answer:
Its sound will not be heard outside.

Observe and Discuss.

Observe the figure and answer the questions.

Question 1.
Which of these sounds is pleasant?
Answer:
The singing of the girl is a pleasant sound.

Question 2.
Which sound is a nuisance to people?
Answer:

1. Boy shouting/screaming.
2. Boy moving/ walking with a toy rattle.

Observe the figure and answer the following.

Question 1.
Make a list of all sounds implied in the picture.

Answer:

1. Chirping of bird outside the house on the tree.
2. Collision of two vehicles – honking of the vehicles.
3. Baby crying.
4. Father talking on the phone.
5. Brother playing in the house – jumping.
6. Sister playing the drum – hitting the drum.
7. Sound of TV.
8. Dog barking.
9. Mother talking to the neighbour.

Question 2.
How would this atmosphere affect a person who is not feeling well?
Answer:
This atmosphere is not convenient for a patient who is ill. He cannot take rest.

Question 3.
Would you be able to study in these conditions?
Answer:
No, students cannot study in this condition. They cannot concentrate on their study.

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 14 Light and the Formation of Shadows Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 Science Solutions Chapter 14 Light and the Formation of Shadows

Class 6 Science Chapter 14 Light and the Formation of Shadows Textbook Questions and Answers

1. Choose an appropriate word and fill in the blanks.

Question a.
A ……………. is a natural source of light.
Answer:
star

Question b.
A ………….. is an artificial source of light.
Answer:
candle

Question c.
When light passes through a prism, it gets separated into ………….. colours.
Answer:
seven

Question d.
The image obtained in the pinhole camera is …………. .
Answer:
inverted

Question e.
A shadow is formed when an …………… object comes in the way of light.
Answer:
opaque

Question f.
When a ………….. object comes in the way of light, light passes …………… it. options : seven, star, through, transparent, opaque, colors, shape, erect, inverted, luminous, candle.
Answer:
transparent, through

2. Write whether the following objects are luminous or non-luminous.

Question a.

Answer:

Object	Luminous /Non-luminous
A book	Non-luminous
A burning candle	Luminous
A wax cloth	Non-luminous
A pencil	Non-luminous
A pen	Non-luminous
A light bulb	Luminous
A tyre	Non-luminous
A torch	Luminous
Stars	Luminous
The planets	Non-luminous
A satellite	Non-luminous
The Moon	Non-luminous

3. Match the following.

Question a.

Natural sources of light	Man-made sources of light
The Sun	Tubelight
Stars in the night sky	Light bulb
Fireflies	Torch
Anglerfish	Burning candle
Honey mushroom	Oil lamps

Answer:

Transparent	Opaque	Translucent
Piece of glass Water	White plastic Tea kettle Note book Cloth Wooden cupboard	Tinted glass Oil paper Sheet of notebook Wax paper

4. Write the answers to the following.

Question a.
What things are necessary for the formation of a shadow?
Answer:
Things necessary for the formation of a shadow are:

1. A source of light
2. An object
3. A surface or screen on which the shadow is formed

Question b.
When can an object be seen?
Answer:
We can see an object when reflected rays reach our eyes.

Question c.
What is a shadow?
Answer:

1. If an opaque object comes in the way of a light source, light does not pass through it.
2. As a result the light does not reach a wall or any other surface on the other side of the object.
3. That part remains dark. This dark part is called the shadow of the object.

Project:

Question 1.
Prepare a Newton’s disc.

Question 2.
Find out how to save electricity with the help of the sunlight we receive during the day.

Question 3.
Read a biography of Sir C. V. Raman and find out about the discoveries he made.

Class 6 Science Chapter 14 Light and the Formation of Shadows Important Questions and Answers

Fill in the blanks.

Question 1.
The ……………. is the main natural source of light.
Answer:
Sun

Question 2.
The light emitted by an electric torch is more …………….. than that obtained from a candle.
Answer:
intense

Question 3.
The left and right sides of the original object appear to be …………….. in the mirror.
Answer:
exchanged

Question 4.
The image is as far behind the mirror as the object is in ……………… of it.
Answer:
front

Question 5.
The …………….. of the image is the same as that of the object.
Answer:
height

Question 6.
The materials through which light passes is said to be …………… .
Answer:
transparent

Question 7.
The materials through which light does not pass is said to be ………….. .
Answer:
opaque

Question 8.
The materials through which light passes partially is said to be ………….. .
Answer:
translucent

Question 9.
If an ………….. object comes in the way of a light source, light does not pass it.
Answer:
opaque, through

Question 10.
The shadow of an object formed due to sunlight is ………….. in the mornings and evenings and ……………. in the afternoon.
Answer:
long, short

Question 11.
The shadow of an object is formed only when ………….. does not pass through the object.
Answer:
light

Question 12.
Stars are ………….. .
Answer:
luminous

Question 13.
Planets, satellites are ………….. .
Answer:
non-luminous

Question 14.
The largest sundial is at ………….., New Delhi.
Answer:
Jantar Mantar

Question 15.
………….. is celebrated as National Science Day.
Answer:
28th February

Question 16.
Light travels in a straight line. This is called ………….. .
Answer:
linear propagation of light

Question 17.
The image formed on the diaphragm of the pinhole camera is ………….. .
Answer:
inverted

Question 18.
The kind of shadow an object forms depends upon the ………….. between the ………….., the object and the ………….. or the ………….. on which the shadow is formed.
Answer:
relative distance, source of light, surface, screen

State whether following statements are True or False.

Question 1.
Light travels in a straight line.
Answer:
True

Question 2.
Stars are luminous.
Answer:
True

Question 3.
Image in a pinhole camera is inverted.
Answer:
True

Question 4.
In the afternoon, shadows are long.
Answer:
False

Question 5.
Fireflies are a natural source of light.
Answer:
True

Question 6.
We see the candle clearly when we bend the tube.
Answer:
False

Question 7.
We can see our image clearly in running water.
Answer:
False

Question 8.
Tracing paper is transparent.
Answer:
False

Question 9.
The light obtained from an electric torch is more intense than that obtained from a candle.
Answer:
True

Question 10.
28tn February is celebrated as “National Science day” since 1987 in India.
Answer:
True

Question 11.
Classify the following into natural and man-made/artificial sources of light. (tubelight, light bulb, torch, burning candle, the sun, fireflies, anglerfish, honey mushroom, stars in the night sky, oil lamps, lanterns)
Answer:

Natural sources of light	Man-made sources of light
The Sun Stars in the night sky Fireflies Anglerfish Honey mushroom	Tubelight Light bulb Torch Burning candle Oil lamps Lanterns

Question 12.
Identify the transparent, opaque and translucent objects from among the following. (piece of glass, wax paper, tinted glass, oil paper, white plastic, a tea kettle, a notebook, cloth, water, a wooden cupboard, sheet of notebook.)
Answer:

Transparent	Opaque	Translucent
Piece of glass Water	White plastic Tea kettle Notebook Cloth Wooden cupboard	Tinted glass Oil-paper Sheet of notebook Wax paper

Question 13.
Classify the following into the type of images they form: Clear image, faint image, no image. (still clear water, cemented wall, wooden surface, new steel dish, flower, glossy granite cladding of a wall, mirror, butter paper).
Answer:

Clear Image	Faint Image	No Image
Still clear water, New steel dish, Glossy granite cladding of a wall, Mirror	Butter paper	Wooden surface Flower Cemented wall

Question 14.
Relate images formed with the surfaces.
Answer:

1. The clear images are formed on plane surfaces.
2. Faint or no images are formed on rough surfaces.

Answer in one sentence.

Question 1.
What are luminous objects?
Answer:
The objects which emit light i.e. which themselves are a source of light, are called luminous objects.

Question 2.
What determines the intensity of light?
Answer:
The intensity of light is determined by the extent to which the objects emit light.

Question 3.
What are non-luminous objects?
Answer:
The objects that are not sources of light themselves are called as non-luminous objects.

Question 4.
What are artificial sources of light?
Answer:
Man-made objects which emit light are artificial sources of light.

Question 5.
What are natural sources of light?
Answer:
Natural substances, materials which emit light are called natural sources of light.

Question 6.
What is linear propagation of light?
Answer:
Property of light travelling in a straight line is linear propagation of light.

Question 7.
What is reflection of light?
Answer:
The rays of light falling on an object from a source of light are thrown back from the substance of that object. This is reflection of light.

Question 8.
How do we see objects around us?
Answer:
The rays of light falling on an object from a source of light are thrown back from the surface of that object. This is called reflection of light. We see the object when the reflected rays reach our eyes.

Question 9.
What is moonlight?
Answer:
Sunlight reflected from the surface of the moon reaching us, in which we see the moon is called the moonlight.

Question 10.
What type of image is formed in the mirror?
Answer:
The image formed in the mirror is ‘laterally inverted’ i.e. right side appears as left side and left side appears as right side.

Question 11.
What change do you see in the image if you decrease or increase your distance from the mirror?
Answer:
When the distance between object and mirror is increased the size of image decreases where as, when the distance is decreased the image size increases.

Question 12.
What difference do you find in the height of the image in the mirror and yourself?
Answer:
The size of the image in the mirror is the same as that of the object.

Question 13.
What is the image on the diaphragm of the pinhole camera?
Answer:
An inverted or an upside down image of the candle is seen on the diaphragm of the pinhole camera.

Question 14.
What do you mean by transparent object?
Answer:
The objects / materials through which light passes are said to be transparent.

Question 15.
What do you mean by opaque materials?
Answer:
The materials through which light does not pass are said to be opaque.

Question 16.
What do you mean by translucent materials?
Answer:
The materials through which light passes partially are said to be translucent.

Question 17.
How is the shadow in the morning, afternoon and evening?
Answer:
The shadows are long in the mornings and evenings and short in the afternoon.

Question 18.
What is shade of a tree?
Answer:
The shade of a tree is its shadow.

Question 19.
How many colours is sunlight made up of?
Answer:
Sunlight is made up of seven colours.

Give reasons for the following.

Question 1.
When we see in the mirror, we see our image in the mirror.
Answer:
When we see our face in the mirror, the light reflected from our face falls on the mirror and gets reflected back again. Hence, we see our image in the mirror.

Question 2.
Opaque materials cast shadow.
Answer:
An opaque material does not allow light to pass. Hence, it casts a shadow.

Question 3.
Transparent and translucent object do not cast a shadow.
Answer:
Translucent objects cast a faint shadow whereas transparent objects do not cast a shadow at all because they allow light to pass through them.

Use your brain power!

Question 1.
Why is the image on the diaphragm of the pinhole camera inverted?
Answer:
1. The pinhole camera works on the principle of light travelling in a straight line.
2. The rays of light from the candle flame go in all directions.
3. We consider only two rays that pass through the hole and fall on the screen.

4. The rays intersect at the pinhole.
5. Since the rays cross over at that point, the top of the object appears at the bottom of the image and the bottom of the image appears at the top. Thus, we see an inverted image of the candle.

Question 2.
How will you light up a dark room using reflected light?
Answer:
Focusing on the wall with torch light. Mirrors or reflectors can be used to get light from outside.

Question 3.
Try to start the TV by operating the remote control from behind it.
Answer:
T.V will not start.

Question 4.
In which step is the flame of the candle seenclearly? Why?

Answer:
In step 1 the flame of the candle is seen clearly because light travels in straight line.

Can you tell?

Question 1.
Can we see anything in total darkness?
Answer:
No, we cannot see anything in total darkness.

Question 2.
What helps us to see the objects around us?
Answer:
Reflected light helps us to see objects around us.

Question 3.
What does the light in each one of the pictures originate form?
Answer:

1. Bulb
2. Firefly
3. Candle
4. Sun

Question 4.
Name the natural sources of light.
Answer:
Sun, Fireflies

Question 5.
In which objects do we see our reflection?
Answer:
All objects reflect light rays, but the best reflectors of light are mirrors, still water in a lake, new steel dish i.e. smooth shiny surfaces.

Question 6.
What difference do you notice on looking through the windows in the picture? What causes the difference? The picture shows transperant, opaque, translucent window panes. Spot them.

Answer:

1. Through the first window we can see a clear picture of things outside.
2. Second window gives a faint image.
3. Through the third window, we can’t see anything
4. The difference in the image is due to the material of the window panes.
5. The first window pane is transparent.
6. The second window pane is translucent.
7. The third window pane is opaque.

Answer the following questions in brief.

Question 1.
List factors on which shadow depends.
Answer:
Shadow depends on relative distance between the source of light, the object and the surface on which the shadow is formed.

Question 2.
How we can see that light travels in straight line.
Answer:

1. In the morning or in the afternoon, rays of light enter a slit in a door, window or a small hole in the roof.
2. As these rays of light from the slit or the hole move towards the floor, the dust particles in their way are clearly seen.
3. Due to these particles, the path of light becomes visible to us.
4. Thus we can see that their path is along straight lines.

Question 3.
What is the difference between an object and its reflection? What causes the difference?
Answer:

1. Object and its reflection result in formation of images.
2. Reflections taking place from highly polished metals, mirrors, still water etc, form clear images.
3. Reflections taking place from wooden surface, flower, book form dull, blurred images.
4. The difference in reflections is caused by the surface of the object.
5. Regular reflections have smooth, polished surfaces, hence, image is clear.
6. Diffused reflections have hard, rough surfaces, hence, image is dull.

Question 4.
List characteristics of images in a plane mirror.
Answer:

1. The left and right sides of the original object appear to be exchanged in the mirror image.
2. The image is as far behind the mirror as the object is in front of it.
3. The size of the image is the same as that of the object.

Question 8.
State the characteristics of image formed by a pinhole camera.
Answer:
Characteristics of an image formed by a pinhole camera are as follows:

1. It is inverted/upside down.
2. It can be obtained on a screen – real image.

Try this.

Question 1.
Make your friend stand in between the torch and the wall. What happens?
Answer:
Friend’s Shadow forms on the wall.

Question 2.
Place a glass filled with water on a sheet of paper in the window so it receives direct sunlight. What is seen on the paper?
Answer:
We see rainbow colours on the paper.

Question 3.
Can we do the same in a dark room with the help of a prism and a torch? What do we learn from this?
Answer:
yes, we can. Light gets seperated into seven colour. From this we learn that white light contains seven colours.

Question 4.
If you dip the wire loop in the soap water and then blow it, soap bubbles are formed. Are the beautiful colours of the rainbow seen in these bubbles?
Answer:
Yes, splitting of white light into different colours takes place.

Question 5.
What do you see on holding a CD in the sun?
Answer:
CD reflects rainbow colours, and interesting : patterns.

Question 6.
Raise your right hand. In mirror which hand of the mirror image is raised?
Answer:
Left hand of the mirror image is raised.

Question 7.
Is there any difference between your height and height of the mirror image?
Answer:
The height remains the same.

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 10 Force and Types of Force Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 Science Solutions Chapter 10 Force and Types of Force

Class 6 Science Chapter 10 Force and Types of Force Textbook Questions and Answers

1. Choose the term and fill in the blanks:

Question a.
……….. has to be applied to change the ……….. of a ……….. object.
(moving, direction, force)
Answer:
force, direction, moving

Question b.
When an elephant drags a wooden log over the land, the forces that are applied on the log are …………., ………. and …………. .
(muscular force, mechanical force, gravitational force, frictional force)
Answer:
muscular force, gravitationalforce, frictionalforce.

Question c.
A ball was set rolling on a large table. If its …….. has to be changed, a ……….. will have to be applied on it.
(force, motion, gravitation)
Answer:
motion, force

Question d.
The force of friction always acts ……….. the motion.
(along, against)
Answer:
against

2. Match the following:

Question a.

Column ‘A’	Column ‘B’
1. An ox pulling a cart	a. Magnetic force
2. Lifting heavy iron object with a crane	b. Electrostatic force
3. Weighing with a spring balance	c. Muscular force
4. Applying brakes to a bicycle.	d. Gravitational force
5. Picking up pieces of paper with a plastic scale.	e. Frictional force

Answer:

Column ‘A’	Column ‘B’
1. An ox pulling a cart	c. Muscular force
2. Lifting heavy iron object with a crane	a. Magnetic force
3. Weighing with a spring balance	d. Gravitational force
4. Applying brakes to a bicycle.	e. Frictional force
5. Picking up pieces of paper with a plastic scale.	b. Electrostatic force

3. One or more forces are acting in the following examples. Name them.

Question a.
An object falling from a tall building …………. .
Answer:
Gravitational force

Question b.
An aeroplane flying in the sky. …………. .
Answer:
Mechanical force

Question c.
Sqeezing sugarcane juice with a squeezer. …………. .
Answer:
Muscular or mechanical force

Question d.
Winnowing foodgrain …………. .
Answer:
Muscular force, gravitational force

4. Explain in your own words giving one example each.
Muscular force, gravitational force, mechanical force, electrostatic force, the force of friction and magnetic force.

Question a.
Muscular force:
Answer:
The force applied with the help of muscles is called muscular force.
e.g. When a bullock pulls the load of a cart with sugarcane, he uses the force of his muscles that is muscular force.

Question b.
Gravitational force:
Answer:
The force applied by the earth to pull the objects towards itself is called gravitational force.
e.g. When a fruit falls from a tree, it is the gravitational force of the earth that pulls the fruit.

Question c.
Mechanical force:
Answer:
The force applied by means of a machine is called mechanical force. Some machines run by muscular force while some use electricity or fuel.
e.g.Washing machine, electric pump uses electricity to work.

Question d.
Electrostatic force:
Answer:
Static electricity is produced on materials like rubber, plastic and ebonite due to friction. The force exerted by such electrically charged materials is called electrostatic force, e.g. When a plastic comb is rubbed against the dry hair, comb develops electrostatic charge.

Question e.
The force of friction:
Answer:
When two surfaces rub against each other, a force of friction is produced. This force always acts against direction of motion, e.g. A ball rolling over a flat surface stops at certain distance due to friction between the ball and the surface.

Question f.
Magnetic force:
Answer:
The force exerted by a magnet is called magnetic force.
e.g. In a pin holder, the magnet attracts the pins.

5. Why?

Question a
Machines are oiled from time to time.
Answer:
To reduce the friction between the parts of machines, they are oiled. This will help efficient working of machines.

Question b.
An object thrown upwards comes down after reaching a point.
Answer:
An object is pulled by the gravitational force of the earth. Hence an object thrown upwards comes down after reaching at certain point.

Question c.
Powder is sprinkled on a carrom board.
Answer:
When powder is sprinkled on a carrom board, friction between the coin and the board decreases so that the coin can be pocketed easily.

Question d.
The ramp at a railway station has a rough surface.
Answer:
The rough surface of the ramp increases the friction between feet and the surface. This helps us to walk on the ramp without skidding or falling.

6. In what way are we different? 

Question a.
Muscular force and Mechanical force
Answer:

Muscular force		Mechanical force
1. The force applied with the help of muscles is called muscular force. e.g. A boy kicking a football.		1. The force applied by means of machine is called mechanical force. e.g. An electric pump works on electricity.
2. It is created by our muscles.		2. It is created by electricity or fuel or muscular force

Question b.
A force of friction and Gravitational force
Answer:

Force of friction		Gravitational force
1. When two surfaces rub against each other, the force of friction comes into force.		1. The force applied by the earth to pull an object towards itself, is called a gravitational force.
2. It comes to act between two surfaces.		2. It exists between two objects or an object and the earth.

7. Write answers to the following questions in your own words. 

Question a.
What are the things that can be done by applying force?
Answer:
By applying force:

1. we can set an object in motion.
2. we can stop a moving object.
3. we can change the speed or direction or both of a moving object.
4. we can change the shape of an object.

Question b.
What is meant by weight?
Answer:

1. The gravitational force acting on an object is called its weight.
2. Greater force must be applied to lift a greater weight.

Question c.
Which machines run on muscular force?
Answer:
The machines that run on muscular force are:

1. Bicycle
2. Hand cart
3. Boat
4. Cycle rickshaw
5. Stretching of a spring
6. Ball pen
7. Vegetable chopper
8. Sharpener
9. Pulley
10. Fruit peeler

8. Solve the following crossword puzzle.

Question a.
Solve the following crossword puzzle.

Down:
1. ………. force is applied to push a scooter that has failed.
2. ………. force can be used to pick up scattered pins.

Across:
3. A ………. pulls iron nails towards itself.
4. ……….. force is used when farm is ploughed with a tractor.
5. It is due to the force of ………… that raindrops fall to the ground.
Answer:

Activity:

Question 1.

Collect more information about the various forces that are used in our day-to-day life.

Question 2.
Make a list of such actions where many forces are applied simultaneously.

Class 6 Science Chapter 10 Force and Types of Force Important Questions and Answers

Choose the term and fill in the blanks:

Question 1.
When powder is sprinkled on a carrom board, friction ……….. .
(increases, decreases)
Answer:
decreases

Question 2.
Electrostatic force is due to …………. .
(gravitation, friction)
Answer:
friction

Question 3.
Fruits fall on the ground due to ………… force.
(mechanical, gravitational)
Answer:
gravitational

Question 4.
Friction between two rough surfaces is …………. than between two smooth surfaces.
(greater, lesser)
Answer:
greater

Question 5.
The sound created by a stone dropped in a bucket of water from 100 cm height is ………… than that dropped from 20 cm height.
(milder, louder)
Answer:
louder

Question 6.
A scooter has stopped in the middle of the road as the petrol tank has become empty. So Raju has to use …………. force to take it to petrol pump.
(mechanical, muscular)
Answer:
muscular

One or more forces are acting in the following examples. Name them.

Question 1.
Srikant is playing basketball
Answer:
Muscular force

Question 2.
Raju rubs a peacock feather between pages of his notebook
Answer:
Electrostatic force

Question 3.
When you rub the palm of your hands, you feel the heat on the palms
Answer:
Frictional force

Question 4.
A blacksmith uses a hammer to beat the hot piece of iron
Answer:
Muscular force

Question 5.
A cricketer hits the ball, but it stops just before the boundary line
Answer:
Frictional force

Question 6.
We can walk on the road without falling down.
Answer:
Frictional force

Give scientific reasons:

Question 1.
Magnet is used to lift heavy iron bar.
Answer:
A magnet attracts the iron bar. As a result it is easier to lift the heavy iron bar using magnetic force.

Question 2.
An inflated balloon when rubbed against a silk cloth, pulls the hair on our skin.
Answer:
When an inflated balloon is rubbed against a silk cloth, it develops electrostatic force due to friction. This force pulls the hair on our skin.

Question 3.
We are likely to slip when we walk on a oily or wet floor.
Answer:
Wet or oily floor reduces the friction between our feet and surface. Hence we are likely to slip on wet or oily floor.

Distinguish between:

Question 1.
Force of friction and Electrostatic force
Answer:

Force of friction	Electrostatic force
1. It exists between any two surfaces in contact.	1. It develops where certain objects are rubbed  against certain material.
2. No electric charge is developed, sometimes heat is developed. e.g. A brake is applied on a bicycle.	2. Electric charge is developed. e.g. Thermocol rubbed against silk cloth.

Answer the following:

Question 1.
Why do planets revolve round the sun in definite orbits?
Answer:

1. The gravitational force operates between the sun and the planets in the solar system.
2. Hence, they revolve round the sun in definite orbits.

Question 2.
Which forces are acting upon an aeroplane taking off into the sky?
Answer:
Aeroplane uses mechanical force, Pilot exerts muscular force. Frictional force between aeroplane and air, gravitational force due to weight of an aeroplane.

Question 3.
What happens to the iron nail when the magnet is taken away from it?
Answer:

1. As we take the magnet away from the iron nail, it does not attract the iron nail as magnetic force decreases.
2. Magnet is unable to exert force if the nail is not placed in the range of the magnetic field.

Question 4.
When brakes are applied while riding a bicycle, it stops after running a distance. Why?
Answer:

1. When brakes are applied while riding a bicycle, frictional force comes to act between the tyres of the bicycle and the surface.
2. This force opposes the tendency of the bicycle to stop.
3. Hence, the bicycle has to overcome this force before it stops.

Can you tell?

Question 1.
What happens when you hold the two ends of a spring and pull them apart?
Answer:
Its shape changes due to the force exerted by pull.

Question 2.
What happens when a blacksmith hammers a red hot piece of iron?
Answer:
Shape of iron piece changes.

Observe and discuss:

Observe the figures given and name the force needed for the motion.

Question 1.
Boat with boatman.

Answer:
Muscular force

Question 2.
Bullock cart.

Answer:
Muscular force

Question 3.
A tractor.

Answer:
Mechanical force

Question 4.
Sewing machine.

Answer:
Mechanical force

Question 5.
Fruit falling from tree.

Answer:
Gravitational force

Question 6.
A man carrying heavy sac.

Answer:
Gravitational force

Question 7.
A pin holder.

Answer:
Magnetic force

Question 8.
A ramp.

Answer:
Gravitational force

Question 9.
Carrom board.

Answer:
Frictional force

Question 10.
Mixer grinder.

Answer:
Mechanical force

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 15 Fun with Magnets Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 Science Solutions Chapter 15 Fun with Magnets

Class 6 Science Chapter 15 Fun with Magnets Textbook Questions and Answers 

1. How will you do this?

Question a.
Determine whether a material is magnetic or non-magnetic.
Answer:

1. To determine whether the material is magnetic or non-magnetic, a magnet is moved over it.
2. If the material sticks to the magnet, it is called magnetic material.
3. If the material does not stick to the magnet, it is non-magnetic.

Question b.
Explain that a magnet has a certain magnetic field.
Answer:

1. The space around a magnet in which the magnetic force is active is called the magnetic field.
2. Place a white paper on a drawing board and place a bar magnet in the middle of the paper.
3. Spread the iron filings on the sheet and gently tap the sheet.
4. The iron filings arrange around the magnet in definite curved lines forming a symmetric pattern.
5. The lines are closer to each other near the poles and less crowded in the middle region around the magnet.
6. Beyond a particular region, the iron filings, will not get attracted.
7. The region where iron filings are attracted is the magnetic field of the magnets.

Question c.
Find the north pole of a magnet.
Answer:

1. Take a bar magnet. Tie a thread to the centre of a bar magnet and hang it from a stand.
2. Note the direction in which the magnet settles and turn it around again.
3. Allow it to settle and note the direction.
4. The end of the magnet that points to the north is called the north pole, while the end that points to the south is called the south pole.
5. The north pole is indicated by ‘N’ and the south pole by ‘S’.

2. Which magnet will you use?

Question a.
Iron is to be separated from a trash.
Answer:

1. Sharp and heavy iron scrap material is attached to a big disc.
2. The disc is a magnet and all scrap is attracted to it.
3. It is not possible to create, store such a big size magnet. Therefore magnetism is induced in the disc with the help of electricity.

An electromagnet is used which is attached to a crane for loading and unloading, transporting scrap and loose iron material from a trash.

Question b.
You are lost in a forest.
Answer:

1. If we are lost in a forest, we should take help of a mariner’s compass which will help us to find the directions while travelling through unknown regions.
2. If mariner’s compass is not available, a bar magnet when suspended in the centre will rest in north-south direction.

Question c.
A window shutter opens and shuts continuously in the wind.
Answer:
A bar magnet can be attached to the window pane so that the window will be closed tight during strong winds also.

3. Fill in the blanks with appropriate word.

Question a.
If a bar magnet is hung by a thread tied at its centre, its north pole becomes steady in the direction of the …………… pole of the earth. (south, north, east, west)
Answer:
North

Question b.
If a bar magnet is cut into equal pieces by cutting it at right angles to its axis at two pieces …………… bar magnets are formed, and a total of …………… poles are formed. (6,3,2)
Answer:
3, 6

Question c.
There is a repulsion between the …………… poles of a magnet and attraction between its ……………. poles. (opposite, like.)
Answer:
like, opposite

Question d.
When magnetic material is taken close to a magnet, the material acquires …………… . (permanent magnetism, induced magnetism, temporary, magnet keeper)
Answer:
induced magnetism

Question e.
If a magnet attracts a piece of metal, that piece must be made of ………… .(any other metal but iron, magnetic material or iron, non-magnetic material, electromagnets)
Answer:
magnetic material or iron

Question f.
A magnet remains steady in a ………….. direction. (east-west, north-south,)
Answer:
north-south

4. Write the answers in your words.

Question a.
How is an electromagnet made?
Answer:
1. To make an electromagnet we need the following apparatus; An iron nail of 10 cm length, 1 metre long insulated copper wire, a battery cell, pins.
2. Wind the copper wire around the nail as shown in the figure. Connect the free ends of the wire to the two terminals of a cell through a plug key.
3. Close the key to complete the circuit.
4. Bring small pins near the tip of the nail and observe.
5. When the circuit is completed, the iron pins are attracted by the nail and hence, they stick to the nail.

6. When the circuit is broken, the pins fall off.
7. A magnet is prepared by passing an electric current through an insulated wire wound around the iron nail. This is an electromagnet.
8. When the current is allowed to pass, the nail becomes a magnet and attracts pin / pins stick to it.
9. When the current is put off the nail does not behave as a magnet and therefore, pins fall off.
10. The magnetism is temporary in the case of an electromagnet.

Question b.
Write the properties of a magnet.
Answer:
Magnet possess following properties/ characteristics.

1. Magnet always settles in the north-south direction.
2. The magnetic force is concentrated at the two ends or poles of a magnet.
3. If a magnet is divided into two parts, two independent magnets are formed. It means that the two poles of a magnet cannot be separated from each other.
4. A magnetic material acquires magnetism when placed near a magnet. This magnetism is called induced magnetism.
5. There is repulsion between like poles of a magnet, while there is attraction between the opposite poles.

Question c.
What are the practical uses of a magnet?
Answer:

1. Magnets are materials to which objects made from iron, nickel, cobalt are attracted. But man explored magnets and its properties and made his life comfortable.
2. Permanent Magnets: are used in caps of pin holders, doors of fridges, doors of cupboards etc.
3. Temporary magnets: Electromagnets are used in electric bells, circuit of various machines, ATM card swipe machines, MRI- Magnetic Resonance Image, loudspeakers, electric cranes, microphones, Mariner’s compasses, etc.

Activity

Question 1.
Collect information regarding how the various magnets used in our day-to-day tasks are produced.

Question 2.
Collect information about the magnetism of the earth.

Class 6 Science Chapter 15 Fun with Magnets Important Questions and Answers

Fill in the blanks.

Question 1.
Iron objects ………….. to a magnet.
Answer:
stick

Question 2.
A magnet is used in ………….. and ………….. .
Answer:
gadgets and machines

Question 3.
The materials that stick to a magnet are called ………….. materials.
Answer:
magnetic

Question 4.
Materials that do not stick to a magnet are called ………….. materials.
Answer:
non-magnetic

Question 5.
When a magnet attracts an object, that object is ………….. due to the magnetic force.
Answer:
displaced

Question 6.
Magnetism is a form of ………….. .
Answer:
energy

Question 7.
A magnet always settles in the ………….. direction.
Answer:
north-south

Question 8.
The north pole is indicated by’ …………… and the south pole by ‘……………’.
Answer:
‘N’-‘S’

Question 9.
The end of the magnet that points to the north is called the ………….. .
Answer:
Northpole

Question 10.
The end of the magnet that points to the south is called the ………….. .
Answer:
South pole

Question 11.
The magnetic force is concentrated at the two ends or ………….. of a magnet.
Answer:
poles

Question 12.
If a magnet is divided into two parts, two ………….. magnets are formed.
Answer:
independent

Question 13.
It means that the two poles of a magnet cannot be ………….. from each other.
Answer:
separated

Question 14.
A magnetic material acquires magnetism when placed near a
Answer:
magnet

Question 15.
Iron filling stick to the iron bar when the ………….. is near it.
Answer:
magnet

Question 16.
There is ………….. between like poles of a magnet.
Answer:
repulsion

Question 17.
There is ………….. between the opposite poles of a magnet.
Answer:
attraction

Question 18.
Magnetic objects ………….. magnetism.
Answer:
induce

Question 19.
Material ………….. is a mixture of aluminium, nickel and cobalt.
Answer:
Alnico

Question 20.
………….. magnets are made from a mixture of nickel, cobalt and iron.
Answer:
Permanent

Question 21.
The bar of soft or pure iron which protects a magnet is called ………….. .
Answer:
magnet keeper

Question 22.
Magnetism gets ………….. when a magnet is heated, thrown, knocked about or broken into pieces.
Answer:
destroyed

Question 23.
Electromagnetic energy is used in our ………….. life.
Answer:
day-to-day

Question 24.
The metals iron, cobalt, nickel are ………….. materials.
Answer:
magnetic

Question 25.
………….. is a natural magnet.
Answer:
Magnetite

Match the columns.

Question a.

Column ‘A’	Column ‘B’
1. Iron, nickel, cobalt	(a) Electromagnet
2. Door bell magnet	(b) Permanent magnet
3. Nickel, cobalt, aluminium	(c) Magnetic metal
4. Cupboard magnet	(d) Mariner’s compass
5. Lodestone	(e) Alnico

Answer:

Column ‘A’	Column ‘B’
1. Iron, nickel, cobalt	(c) Magnetic metal
2. Door bell magnet	(a) Electromagnet
3. Nickel, cobalt, aluminium	(e) Alnico
4. Cupboard magnet	(b) Permanent magnet
5. Lodestone	(d) Mariner’s compass

State whether true or false. If false, correct the statement.

Question 1.
Material alnico is a mixture of aluminium, nickel and iron.
Answer:
False: Material alnico is a mixture ofaluminium, nickel and cobal.

Question 2.
Magnetism of electromagnet is permanent.
Answer:
False: Magnetism of electromagnet is temporary.

Question 3.
The bar of soft or pure iron protects the magnet.
Answer:
True

Question 4.
Like poles attract each other and unlike poles repel each other.
Answer:
False: Like poles repel each other and unlike poles attract each other.

Question 5.
The magnetic force is concentrated at the centre of the magnet.
Answer:
False: The magnetic force is concentrated at the poles of the magnet

Question 6.
Magnetism is a kind of energy.
Answer:
True

Question 7.
Mariner’s compass is used for finding directions while travelling.
Answer:
True

Question 8.
Cobalt is a magnetic material.
Answer:
True

Question 9.
The north pole is indicated by ‘S’ and the south pole is indicated by ‘N’.
Answer:
False: The north pole is indicated by Wand the south pole is indicated by ‘S’.

Question 10.
Electromagnetism is used in many places in our day-to-day life.
Answer:
True

Answer the following questions in one sentence.

Question 1.
What is a magnet?
Answer:
The material to which objects made from iron, nickel, cobalt get attracted is called as magnet.

Question 2.
What is magnetism?
Answer:
The property of a material to which objects made from iron, nickel, cobalt get attracted is called as magnetism.

Question 3.
What are magnetic materials?
Answer:
Materials that stick to a magnet are called magnetic materials, e.g. cobalt, nickel, iron.

Question 4.
What are non-magnetic materials?
Answer:
Materials that do not stick to a magnet are called non-magnetic material, e.g. plastic, rubber, glass etc.

Question 5.
What are lodestones?
Answer:
Lodestones are leading stones which are used for finding the directions while travelling through unknown regions.

Question 6.
How is magnetism a kind of energy?
Answer:
Work is done by magnetic force. Thus, magnetism is a kind of energy.

Question 7.
What is an electromagnet?
Answer:
When magnetism is produced in the iron due to the electric current, it is called an electromagnet.

Question 8.
How are permanent magnets made?
Answer:
Permanent magnets are made from a mixture of nickel, cobalt and iron.

Question 9.
List the instruments where electromagnets are used.
Answer:
Electromagnets are used in doorbells, cranes, loudspeakers, voltameters, TVs, antennas, radios etc.

Question 10.
How is magnetism destroyed?
Answer:
When magnets are heated, thrown, knocked about or broken into pieces, magnetism gets destroyed.

Question 11.
What is a magnet keeper?
Answer:
A magnet keeper is a bar of soft or pure iron which protects a magnet. It is a piece of soft iron placed in the box in which a magnet is kept.

Question 12.
Magnets exist in variety of shapes.
Answer:
Today, magnets are used in many machines, gadgets and devices. They are all man-made. Hence, they can have a variety of shapes depending upon their use.

Answer the following briefly.

Question 1.
What are leading stones?
Answer:

1. It was known quite long ago to the people in China and Europe that a piece of magnetite, hung freely always settled in the north-south direction.
2. These rocks then came to be used for finding the directions while travelling through unknown regions.
3. That is why they are called leading stones or Lodestones.

Question 2.
What has led to the invention of the Mariner’s compass?
Answer:
Leading stones have led to the invention of the mariner’s compass.

Question 3.
List the different shapes of magnets.
Answer:

1. Magnets have a variety of shapes depending on their uses.
2. They are bar magnets, disc magnets, horseshoe magnets, ring shaped magnets, cylindrical magnets, and small button magnets.

Question 4.
What are permanent magnets?
Answer:

1. Magnets which do not lose their magnetism easily are called permanent magnets or Magnets which are made up of magnetic substances are permanent magnets.
2. e.g. Magnets fixed in a pin holder, magnets of a door of a cupboard are permanent magnets.
3. Permanent magnets are made from a mixture of
   • Nickel, cobalt, iron
   • Aluminium, nickel, cobalt – alnico

Give scientific reasons.

Question 1.
Why is it important to place a magnet keeper in a box along with magnets?
Answer:
Magnetism gets destroyed when a magnet is heated, thrown, knocked about or broken into pieces. A magnet keeper which is a bar of soft or pure iron protects a magnet.

Question 2.
Cranes with magnets are used.
Answer:
When a magnet attracts an object, that object is displaced due to the magnetic force. In factories, ports, garbage depots, large objects are lifted and shifted from place to place using cames. Hence cranes are fitted with magnets.

Can you tell?

Question 1.
Pins in a pin holder do not fall? While we are shutting the door of a fridge, we find that it closes automatically from certain distance and does not open unless pulled again.
Answer:
Magnet is fitted in the cap of a pin holder and in the door of a fridge. Iron objects stick to the magnet.

Question 2.
Take a magnet from the laboratory and bring it near various objects in your use. Which of them stick to the magnet? What material is each of them made of? Observe these things carefully. Classify the objects into two groups: those which stick to the magnet, those which do not.
Comb, table, cupboard – iron, spoon, scissors, pen, pencil, eraser, books, mobile, laptops, glass bangles, hair pin, cupboard handle, chair, steel lunch box, magnetic stickers, toys, gold ring.
Answer:

Stick to the magnet	Doesn’t stick to the magnet
Iron cupboard, spoon, scissors, hairpin, steel lunch box, magnetic stickers	Comb, table, pen, pencil, eraser, books, glass bangles, chair, mobile, laptops, cupboard handle, toys, gold ring

Question 3.
Take a mixture of sand, pieces of paper, sawdust, iron filings and pins in a saucer and pass a magnet around the mixture. What do you see?
Answer:
When magnet is moved over a mixture of sand, pieces of paper, sawdust, iron filings and pins, pins and iron filings will cling to the magnet. Sand, sawdust and pieces of paper will remain behind.

Question 4.
How is a Mariner’s Compass used?
Answer:

1. A Mariner’s Compass is a magnetic needle used in navigation to show direction by deflections.
2. It is a direction-finding instrument used in navigation.
3. It is placed on the maps, grounds, decks as it will point to the magnetic north pole.
4. It has two or more magnets permanently attached to a compass card which moves freely on a pivot.
5. The needle fixed on the compass bowl indicates the ship’s heading position.

Question 5.
Find out where the magnet given are used?
Answer:

Magnets	Uses
Horseshoe magnet	used in electric bell
Circular magnet	used in loudspeaker.
Magnetic needle	used in Mariner’s Compass.
Disc magnets	used in toys
Bar magnets	used in cupboard doors
Button magnet	supporting side rails or blockouts
Square magnet	Industries
Arc magnet	Electric motors and generators.
Cylindrical magnet	used in medicine, used in treatment of scoliosis patients.

Question 6.
Identify the different types of magnets as shown in the picture below.
Answer:
a. Circular magnet
b. Cylindrical magnet
c. Horseshoe magnet
d. Bar magnet

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 9 Motion and Types of Motion Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 Science Solutions Chapter 9 Motion and Types of Motion

Class 6 Science Chapter 9 Motion and Types of Motion Textbook Questions and Answers

1. Identify the types of motion.

Question a.
Movement of the earth around the sun: …………… .
Answer:
periodic, drcular

Question b.
Movement of ceiling fan: …………… .
Answer:
circular

Question c.
A rocket launched from the ground: ……….. .
Answer:
linear

Question d.
A fish swimming in water: ……… .
Answer:
random

Question e.
The plucked string of a sitar:………….. .
Answer:
oscillatory motion

2. Fill in the blanks.
(linear, non-linear, uniform linear, non-uniform linear, uniform circular, random, circular, non-uniform circular)

Question a.
If a ball is released from the terrace of a building, it comes down in ………… motion. On the other hand, it reaches the ground in ………… motion if it is thrown with a force away from the terrace in a direction parallel to the terrace.
Answer:
uniform linear, non-uniform linear

Question b.
The motion of an aeroplane on the runway before take off is …………. .
Answer:
linear

Question c.
The kite looking for its prey flies with …………. motion in the sky.
Answer:
circular

Question d.
Children sitting in a rotating giant wheel have ………. motion, while those sitting in a merry-go-round have a ………. motion.
Answer:
uniform circular, non-uniform circular

3. How are we different?.

Question a.
Oscillatory motion and Linear motion.
Answer:

Oscillatory motion	Linear motion
1. In oscillatory motion, body swings back and forth. e.g. Motion of a swing, motion of pendulum of a clock.	1. In linear motion, an object shows displacement in a straight line, e.g. A train in motion, motion of marching soldiers.

Question b.
Linear motion and Random motion
Answer:

Linear motion	Random motion
1. Motion in a straight line is called linear motion. e.g. Motion of a train	1. The motion that changes its direction and speed continuously is called random motion, e.g. Motion of a bird.

Question c.
Random motion and Oscillatory motion
Answer:

Random motion	Oscillatory motion
1 The motion that changes its direction and speed continuously is called random motion, e.g. Motion of a butterfly	1. The motion of a body that is swinging back and forth is called oscillatory motion, e.g. Pendulum of a clock, the wing of a bird.

4. Explain in your own words, giving one example each.

Question a.
Linear motion
Answer:
An object that shows displacement along a straight line is called linear motion, e.g. A vehicle moving on a road.

Question b.
Oscillatory motion
Answer:
The motion of a body swinging back and forth is called oscillatory motion, e.g. Motion of a pendulum of a clock.

Question c.
Circular motion
Answer:
The motion of an object along a circular path is called circular motion, e.g. Motion of a ceiling fan.

Question d.
Random motion
Answer:
The motion that changes its direction and speed continuously is called random motion, e.g. Motion of a butterfly.

Question e.
Periodic motion
Answer:
The repetitive motion in which the moving object passes through a certain point again and again after a fixed period is called as periodic motion, e.g. The minute hand of a clock.

5. Answer the following questions in your own words. 

Question a.
Which types of motion are seen in birds flying in the sky?
Answer:

1. The birds flying in the sky exhibit random motion.
2. The wings of the birds show oscillatory motion.

Question b.
Write in detail about your experience of various types of motion while riding a bicycle on a road.
Answer:

1. The cycle itself shows linear motion.
2. The wheels of the cycle show circular motion.
3. The cycle chain shows periodic motion, if the speed is uniform.
4. The handle bar shows random motion.

6. Complete the puzzle using words for types of motion: 

Question a.
Complete the puzzle using the words for types of motion.
1. A spring is stretched and one end is released.
2. A minute hand.
3. A see-saw.
4-5.  Children in a march past.
6. A stone rolling down a hillside.

Answer:

1. Oscillatory
2. Circular
3. Periodic
4. Uniform
5. Linear
6. Random

Activity:

Question 1.
Make a list of various moving objects in the environment, and discuss the types of motion seen in them.

Class 6 Science Chapter 9 Motion and Types of Motion Important Questions and Answers

Identify the types of motion.

Question 1.
The movement of a see-saw.
Answer:
oscillatory motion

Question 2.
The motion of a moving ant.
Answer:
random

Question 3.
The marching army soldiers.
Answer:
linear

Question 4.
A train approaching a station.
Answer:
non-uniform linear

Question 5.
A meteor falling from the sky.
Answer:
linear

Fill in the blanks with suitable words from those given in the bracket:
(linear, non-linear, uniform linear, non-uniform linear, uniform circular, random, circular, non-uniform circular)

Question 1.
The motion that changes its speed and direction continuously is called ………. .
Answer:
random

Choose the correct alternative:

Question 1.
A baby is crawling. The motion is said to be …………….. .
(a) linear
(b) periodic
(c) circular
(d) random
Answer:
(d) random

Question 2.
The children are having a 50m running race. The motion exhibited is ………….. motion.
(a) linear
(b) periodic
(c) random
(d) circular
Answer:
(a) linear

Question 3.
The motions of the hands of a clock are ………….. and …………. .
(a) periodic, linear
(b) periodic, circular
(c) non-linear, non-uniform
(d) circular, non-uniform
Answer:
(b) periodic, circular

Question 4.
The motion of a pendulum of a clock is ……………. .
(a) linear
(b) oscillatory
(c) circular
(d) random
Answer:
(b) oscillatory

Question 5.
The motion of a butterfly from one flower to another flower is an example of …………… motion.
(a) circular
(b) periodic
(c) linear
(d) random
Answer:
(d) random

Question 6.
The distance traversed by an object in a unit time is called ……….. of that object.
(a) length
(b) motion
(c) speed
(d) displacement
Answer:
(c) speed

Explain it in your own words, giving one example of each.

Question 1.
Uniform linear motion
Answer:
When the distance traversed by an object along a straight line in unit time is the same, the motion is called as uniform linear motion, e.g. Motion of soldiers on parade.

Question 2.
Non-uniform linear motion
Answer:
When the distance traversed by an object along a straight line in unit time keeps on changing, the motion is called non-uniform linear motion.
e.g. A girl coming down a slide.

Question 3.
Non-linear motion
Answer:
The motion of an object that does not move in a straight line is called non-linear motion.
e.g. Motion of a swing,

Question 4.
Speed
Answer:
The distance traversed by an object in unit time is called the speed of that object.
e.g. A boy riding on a bicycle covers a distance of 15 kilometres in 3 hours.
Hence Speed = \(\frac{15}{3}\) = 5 kilometres/hour

Answer the following:

Question 1.
In which muscial instruments can you see oscillatory motion?
Answer:
Vibrating diaphragm of tabla, drum, dhol and strings of sitar, guitar show oscillatory motions.

Question 2.
With reference to types of motion, complete the table below.

Answer:

1. Non-linear
2. Uniform
3. Oscillatory
4. Periodic
5. Random.

Read the following stories and answer the questions.

Rita and Geetha are friends travelling from Mumbai to Pune. Seetha had come to the station to see her friends off. After 15 minutes train starts moving. Rita and Geetha feel that Seetha and the vendors on platform are moving backwards. Whereas, Seetha feels that Rita and Geetha are moving forward. Rita feels Geetha is not in motion and Geetha also feels Rita is not in motion. Can you say why?

Question a.
Are Rita and Geetha in motion?
Answer:
Rita and Geetha are not in motion as far as each other are concerned, as no displacement takes place. Both are in a train. For Seetha, both of them are in motion.

Question b.
Are the vendors and Seetha in motion?
Answer:
No, the vendors and Seetha are not in motion. But Rita and Geetha feel as if they are moving backwards.

Question c.
What can you conclude from this passage?
Answer:
An object which is in motion for one person may not be in motion for another. This shows that motion is relative.

Observe and discuss:

Question 1.
Observe the figure and classify the type of motion.


Answer:

1. Circular motion
2. Linear motion
3. Circular motion
4. Linear motion
5. Oscillatory motion
6. Oscillatory motion
7. Circular motion
8. Circular motion
9. Bird – Random; Wings – Oscillatory motion
10. Circular motion
11. Linear, circular

Can you tell?

Question 1.
While chasing a butterfly in a garden, do you run along a definite path or in the same direction all the time?
Answer:
No, we move in random motion.

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 8 Our Skeletal System and the Skin Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 Science Solutions Chapter 8 Our Skeletal System and the Skin

Class 6 Science Chapter 8 Our Skeletal System and the Skin Textbook Questions and Answers

1. Fill in the blanks with the proper word. 

Question a.
The place where two or more bones are connected is called a …………… .
Answer:
joint

Question b.
Cells of epidermis contain a pigment called ………… .
Answer:
melanin

Question c.
…………… and ……………. are the two layers of the human skin.
Answer:
epidermis, dermis

Question d.
The human skeletal, system is divided into ………….. parts.
Answer:
two

2. Match the pairs.

Question a.

Column ‘A’	Column ‘B’
1. Ball and socket joint	a. Knee
2. Hinge joint	b. Wrist
3. Gliding joint	c. Shoulder

Answer:

Column ‘A’	Column ‘B’
1. Ball and socket joint	c. Shoulder
2. Hinge joint	a. Knee
3. Gliding joint	b. Wrist

3. Right or wrong? If wrong, write the correct sentence. 

Question a.
Bones are soft.
Answer:
Wrong: Bones are hard.

Question b.
The human skeleton protects the internal organs.
Answer:
Right

4. Put a [✓] mark at the proper places.

Question a.
The system which gives our body. a definite shape to
(a) Excretory system [ ]
(b) Respiratory system [ ]
(c) Skeletal system [ ]
(d) Circulatory system [ ]
Answer:
(c) Skeletal system [✓]

Question b.
The ………… joint is seen in fingers and toes.
(a) Hinge joint [ ]
(b) Ball and socket joint [ ]
(c) Immovable joint [ ]
(d) Gliding joint [ ]
Answer:
(a) Hinge joint [✓]

5. Answer the following questions in your words.

Question a.
What are the functions of your skin?
Answer:
The functions of the skin are :

1. Protects the internal parts of the body like muscles, bones, organ systems etc.
2. Help to preserve the moisture in the body.
3. Synthesizing Vitamin D.
4. Regulates body temperature by releasing sweat.
5. Gives protection from heat and cold.
6. Functions as the sensory organ of touch

Question b.
What should you do to keep the bones strong and healthy?
Answer:
To keep the bones strong and healthy:

1. We should include calcium and phosphrous rich food in our diet.
2. We also include vitamin D rich food in our diet.
3. We get these from milk, milk products, leafy vegetables, meat and exposure to sunlight.
4. We should exercise regularly.

Question c.
What are the functions of human skeletal system?
Answer:
The functions of human skeletal system are:

1. Gives a definite shape to the body.
2. Provides support to the body.
3. Protects the delicate organs inside the body.

Question d.
Which are the various reasons due to which our bones might break?
Answer:
The bones in our body might break due to:

1. Lack of calcium and phosphorous.
2. Due to fracture because of an accident or a fall.
3. Lack of proper nutrition.
4. Due to deficiency of Vitamin D.

Question e.
What are the different types of bones? How many types are there? Give example of each.
Answer:
There are four types of bones in our body:

Types of Bone	Example
1. Flat bones	Sternum in the chest
2. Small bones	Stirrup in each ear
3. Irregular bones	Vertebra posterior (back side) of the body
4. Long bones	Femur or thigh bone

Types of Bone Example

1. Flat bones Sternum in the chest
2. Small bones Stirrup in each ear
3. Irregular bones Vertebra posterior (back side) of the body
4. Long bones Femur or thigh bone

6. What will happen if?

Question a.
There are no joints in our body.
Answer:
If there are no joints in our body, we will be standing like a tree without any movement, we can move only because of joints.

Question b.
There is no melanin pigment in our body.
Answer:
We will not have protection from ultraviolet rays. Our skin will become whitish.

Question c.
Instead of 33 vertebras in our body, we had one single and straight bone.
Answer:
We cannot bend down at our will.

7. Draw diagrams.

Question a.
Types of joints.
Answer:

Question b.
Structure of skin
Answer:

Activity:

Question 1.
Collect pictures of the different parts of the human skeletal system and paste them on chart paper. Write the functions of
each, too.

Question 2.
Collect the pictures, newspaper cuttings, etc. which show the skeletal systems of various animals and observe the differences between them.

Class 6 Science Chapter 8 Our Skeletal System and the Skin Important Questions and Answers

Choose the correct alternative:

Question 1.
The ………………….. protects the brain.
(a) skull
(b) rib cage
(c) spine
(d) none of above
Answer:
(a) skull

Question 2.
X-rays were discovered by …………………..  .
(a) Sir C.V.Raman
(b) Galileo
(c) Sir Isaac Newton
(d) Roentgen
Answer:
(d) Roentgen

Question 3.
The bones of ………………….. are immovable.
(a) hand
(b) leg
(c) spine
(d) skull
Answer:
(d) skull

Question 4.
We can move the bones of ………………….. in a 360° angle.
(a) elbow
(b) knee
(c) shoulder
(d) wrist
Answer:
(c) shoulder

Question 5.
Our body temperature usually remains constant at ………………….. °C.
(a) 32
(b) 35
(c) 37
(d) 40
Answer:
(c) 37

Question 6.
The part of the skin which maintains body temperature is ………………….. .
(a) Epidermis
(b) Dermis
(c) Subcutaneous layer
(d) Network of blood vessels and nerve fibers
Answer:
(c) Subcutaneous layer

Fill in the blanks:

Question 1.
Except for the …………….., none of the bones of the skull can move.
Answer:
lower jaw

Question 2.
The spinal cord originates from the …………… .
Answer:
brain

Question 3.
The longest and the strongest bone in the human body is …………… .
Answer:
femur

Question 4.
…………….. is the smallest bone in our body.
Answer:
stirrup

Question 5.
The vertical, flat bone in the chest is called the ……………… .
Answer:
sternum

Question 6.
The …………… joint moves in a 180° angle.
Answer:
hinge

Match the columns:

Question 1.

Column ‘A’	Column ‘B’
1. Skull	a. 25 bones
2. Rib cage	b. 6 bones
3. Spine	c. 22 bones
4. Both ears	d. 33 bones

Answer:

Column ‘A’	Column ‘B’
1. Skull	c. 22 bones
2. Rib cage	a. 25 bones
3. Spine	d. 33 bones
4. Both ears	b. 6 bones

Question 2.

Column ‘A’	Column ‘B’
1. Lower jaw	a. Movable joint
2. Ears	b. Femur
3. Thigh	c. Movable joint in skull
4. Elbow	d. Smallest bone

Answer:

Column ‘A’	Column ‘B’
1. Lower jaw	c. Movable joint in skull
2. Ears	d. Smallest bone
3. Thigh	b. Femur
4. Elbow	a. Movable joint

Right or Wrong? If wrong, write the correct answers:

Question 1.
The spine is a part of the appendicular skeleton.
Answer:
Wrong: The spine is a part of the axial skeleton.

Question 2.
Ankle joints are gliding joints.
Answer:
Right

Question 3.
All the skull joints are immovable.
Answer:
Wrong: Except lower jaw, all the skull joints are immovable.

Question 4.
The skin maintains normal body temperature.
Answer:
Right

Answer in one word:

Question 1.
The part which protects the heart and lungs.
Answer:
Rib cage

Question 2.
Ali falls down and his elbow is broken.
Answer:
Fracture

Question 3.
The image which spots the broken bone.
Answer:
X-ray

Question 4.
The biotic component of our body.
Answer:
Bone cell

Question 5.
The part which protects the vertebral column.
Answer:
Spine

Question 6.
The part which connects the bone in our body.
Answer:
Ligament

Question 7.
The organ which helps us to sense whether something is hot or cold.
Answer:
Skin

Question 8.
The pigment which gives colour to the skin.
Answer:
Melanin

Can you tell?

Question 1.
What is a fracture? How will you help a friend who has met with an accident and fractured his leg?
Answer:
Fracture is a crack or break in a bone. Fracture may occur due to accident or fall from height or injury. If my friend’s leg is fractured, then. I would –

1. Ask him to prevent any movement of the fractured part.
2. Get immediate medical help.
3. Take the x-ray image of the fractured or swollen part.
4. An x-ray image shows the exact spot where the bone is broken. This will help in providing proper treatment.

Question 2.
What are the properties of bones?
Answer:
The properties of bones are:

1. Bones are hard and not flexible.
2. Bone cells are composed of two main constituents:
   • Bone cells are biotic components.
   • Calcium carbonate, calcium phosphate, minerals and salts are abiotic components.
3. Calcium imparts strength to bones.
4. As we grow the size and length of bones increases upto a certain limit.

Question 3.
What is human skeletal system? How is it divided?
Answer:

1. All the bones together form a framework or a skeleton.
2. All the bones of the body along with cartilage together form the skeletal system.
3. The human skeletal system can be divided into two parts – the axial skeleton and the appendicular skeleton.
4. The axial skeleton consists of the skull, the spine and the rib cage. These are situated symmetrically along the central axis.
5. The appendicular skeleton consists of the bones of arms and legs on either side of the central axis.

Question 4.
What is a joint? What are it’s types?
Answer:
Joints are places where two or more than two bones are connected to each other.

Question 5.
Describe the structure of skin.
Answer:

1. Human skin is made up of two main layers- outermost layer, epidermis and layer below it called dermis.
2. Below dermis there is a network of blood vessels and nerve fibers.
3. Under this layer there is a subcutaneous layer, which maintains body temperature.
4. The epidermis has various layers.
5. There are sweat glands in the skin which secrete sweat.

Question 6.
Write a short note on melanin.
Answer:

1. Melanin is a pigment present in the cells of epidermis.
2. Melanin is synthesized in certain glands in the skin.
3. The percentage of melanin decides the fairness or darkness of the skin.
4. Melanin protects our skin and the inner parts from ultraviolet sunrays.

Use your brain power!

Question 1.
Which colour of the skin will give greater protection from sun’s rays?
Answer:
Darker colour will give greater protection.

Give scientific reasons:

Question 1.
We are able to bend down at our will.
Answer:

1. 33 bones of the spine are placed straight one above the other.
2. They are arranged flexibly.
3. Their flexibility allows us to bend down at our will.

Question 2.
Calcium is an important mineral.
Answer:

1. Calcium imparts strength to our bones.
2. If we are calcium deficient, possibility of bone fracture during a fall or an accident increases.
3. Hence, calcium is an important mineral.

Question 3.
Sweating helps to lower the body temperature.
Answer:

1. In the hot sun, the temperature of the skin rises.
2. The sweat is released.
3. The heat required for the evaporation of sweat is drawn from the body itself.
4. Hence, sweating lowers the body temperature.

Question 4.
Some people have jet black hair, while others have brown or reddish hair.
Answer:

1. It is melanin that determines the colour of our hair.
2. Jet black hair is due to pure melanin.
3. Brown hair is due to sulphur in the melanin.
4. Reddish hair is due to iron in the melanin.

Question 5.
Observe and discuss:
Your grandmother has wrinkles on her skin.
Answer:

1. As we grow older, the proportion of fat beneath the skin reduces.
2. However, previously tout skin does not shrink.
3. This causes wrinkles on the face of older people.

What will happen if:

Question 1.
If skin had no sweat glands.
Answer:
Skin regulates body temperature by releasing sweat. If skin had no sweat glands then we will not be able to maintain our body temperature at a constant 37°C.

Can you recall?

Question 1.
Which organ help us to sense whether something is hot or cold, rough or smooth, etc?
Answer:
The skin functions as the sensory organ of touch.

Question 2.
What happens when we walk or play in the hot sun?
Answer:
When we walk or play in the sun, we get tired, our skin secrete sweat.

Observe the figure and label as directed.

Question 1.

In the above figure label the parts marked a, b, c, d, e and hence show axial and appendicular
skeleton.
Answer:
(a) Skull
(b) Rib cage
(c) Spine
(d) Arm
(e) Leg
Axial skeleton: skull, the spine and rib cage
Appendicular: legs, arms

Question 2.

In the given figure, name the type of bones marked a, b, c, d. State where they are seen in our body.
Answer:
(a) Flat bones – rib cage and gliding joint
(b) small bones – finger
(c) Irregular bones – vertebal column
(d) Long bones – legs, arms

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 16 The Universe Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 6 Science Solutions Chapter 16 The Universe

Class 6 Science Chapter 16 The Universe Textbook Questions and Answers

1. Name these.

Question a.
Birthplace of stars.
Answer:
Nebulae

Question b.
The biggest planet in the Solar System.
Answer:
Jupiter

Question c.
The galaxy which is our neighbour.
Answer:
Andromeda

Question d.
The brightest planet in the solar system.
Answer:
Venus

Question e.
Planet with the largest number of satellites.
Answer:
Jupiter

Question f.
Planet without a single satellite.
Answer:
Venus and Mercury

Question g.
Planet with a rotation different from other planets.
Answer:
Venus

Question h.
A celestial body that carries a tail along.
Answer:
Comet

2. Fill in the blanks.

Question a.
The group of galaxies of which our Milky Way is a part is called ………….. .
Answer:
Local group

Question b.
Comets are made of ………… .
Answer:
ice and dust particles

Question c.
The planet ……………… appears as if it is rolling along its orbit.
Answer:
Uranus

Question d.
…………….. is a stormy planet.
Answer:
Jupiter

Question e.
The pole star is the best example of a ………………. type of star.
Answer:
variable

3. Say if the statements given below are right or wrong. Rewrite the statements after correcting them.

Question a.
Venus is the planet closest to the sun.
Answer:
Wrong: Mercury is the planet closest to the sun.

Question b.
Mercury is called a stormy planet.
Answer:
Wrong: Jupiter is called a stormy planet.

Question c.
Jupiter is the biggest planet.
Answer:
Right

4. Answer the following.

Question a.
What is a special characteristic of the planet Mars?
Answer:
The highest and the longest mountain in the solar system ‘Olympus Mons’ is located on Mars.

Question b.
What are the type of galaxies?
Answer:
The different types of galaxies identified according to their shapes are spiral, elliptical, barred spiral, irregular.

Question c.
Which celestial bodies does a galaxy include?
Answer:
Galaxy includes stars, their planetary system, cluster of stars, nebulae, clouds of gases, clouds of dust, dead stars, newly bom stars etc.

Question d.
Name the different types of stars.
Answer:
The different types of stars are

1. Sun-like stars e.g. stars like Sirius, Alpha Centauri
2. Red Giants Stars
3. Super Nova
4. Binary or Twin Stars
5. Variable Stars e.g. Polaris (pole star)

Question e.
What are the types of comets and on what basis are they classified?
Answer:

1.  Comets are of two types: Long-period comets and short-period comets.
2. Classification of comets is based on the time (period) taken by the comets to complete one revolution around the sun.

Question f.
What is the difference between meteors and meteorites?
Answer:

1. Meteors are rocky pieces originating from the asteroid belt. Smaller rocky pieces get completely burnt due to friction with air after they enter the earth’s atmosphere.
2. Meteors which do not bum completely and fall to the surface of the earth are called meteorites.

Question g.
What are the characteristics of the planet Neptune?
Answer:
Neptune is the eighth planet in the solar system. A season on Neptune lasts for about 41 years. On this planet winds blow with extremely high speed.

5. Match the following.

Question a.

Group ‘A’	Group ‘B’
1. Galaxy	(a) From east to west
2. Comet	(b) 33 satellites
3. Sun-like star	(c) Spiral
4. Saturn	(d) Sirius
5. Venus	(e) Halley

Answer:

Group ‘A’	Group ‘B’
1. Galaxy	(c) Spiral
2. Comet	(e) Halley
3. Sun-like star	(d) Sirius
4. Saturn	(b) 33 satellites
5. Venus	(a) From east to west

Activity:

Question 1.
Using the material you can find in your house, prepare a model of the solar system.

Question 2.
Collect information about different aspects of each planet such as its distance from the sun, its diameter, its volume, etc. and present it in a science exhibition.

Class 6 Science Chapter 16 The Universe Important Questions and Answers

Fill in the blanks.

Question 1.
The Milky Way is known as ………….. .
Answer:
Mandakini

Question 2.
The ………….. is a galaxy in which our solar system is located.
Answer:
Milky Way

Question 3.
The galaxy that is closest to our Milky Way is ………….. .
Answer:
Andromeda

Question 4.
The universe includes innumerable galaxies, the space between them and also ………….. .
Answer:
energy

Question 5.
The Milky Way is a part of the ………….. of galaxies.
Answer:
Local group

Question 6.
Generally, the surface temperature of stars ranges from 3500° C to ………….. .
Answer:
50000°C

Question 7.
The colour of stars changes according to their ………….. .
Answer:
temperature

Question 8.
Red giants stars are ………….. in colour.
Answer:
red

Question 9.
Super Nova stars are ………….. and ………….. than the red giant stars.
Answer:
brighter, larger

Question 10.
More than ………….. of the stars in the sky are ………….. stars.
Answer:
half, binary

Question 11.
The ………….. and ………….. of variable stars is not stable.
Answer:
luminance, shape

Question 12.
When a star contracts, its surface temperature ………….. and the star emits ………….. energy and appears ………….. .
Answer:
increases, greater, brighter

Question 13.
The sun which is at the centre of the solar system is a ………….. coloured star.
Answer:
yellow

Question 14.
The diameter of the sun is approximately ………….. km.
Answer:
13, 92, 000

Question 15.
………….. is the fastest moving planet.
Answer:
Mercury

Question 16.
………….. is the brightest planet in the solar system.
Answer:
Venus

Question 17.
………….. is the hottest planet.
Answer:
Venus

Question 18.
As the earth is a ………….. there is a magnetic field around the earth.
Answer:
magnet

Question 19.
Mars is also called the ………….. .
Answer:
Red planet

Question 20.
As the soil on Mars contains ………….. its colour is reddish.
Answer:
iron

Question 21.
………….. planets of the size of the earth can get accommodated on Jupiter.
Answer:
1397

Question 22.
Jupiter is called as ………….. .
Answer:
The stormy planet

Question 23.
Saturn mass is ………….. times that of the earth.
Answer:
95

Question 24.
………….. cannot be seen without a telescope.
Answer:
Uranus

Question 25.
Winds blow with extremely high speed on ………….. .
Answer:
Neptune

Question 26.
………….. is the satellite of the earth.
Answer:
The moon

Question 27.
The moon’s period of ………….. and ………….. are both of 27.3 days.
Answer:
rotation, revolution

Question 28.
………….. is classified as a dwarf planet.
Answer:
Pluto

Question 29.
Pluto takes ………….. years to complete its revolution around the sun.
Answer:
248

Question 30.
………….. are formed out of ice and dust particles.
Answer:
Comets

Question 31.
………….. lake in Maharashtra has been formed by the impact of such a meteorite.
Answer:
Lonar

Can you tell?

Question 1.
Which celestial bodies form the solar system?
Answer:
Sun, the eight planets – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, their satellites, Dwarf planets, asteroids, meteors and comets all together form our solar system.

Question 2.
What is the difference between stars and planets?
Answer:

Stars	Planets
1. Stars are the celestial bodies which can emit heat and light continuously.	1. The celestial bodies which revolve around the sun in certain orbit are called planets.
2. Stars twinkle in the sky.	2. Planets do not twinkle in the sky.
3. They have their own light.	3. They do not have their own light.
4. They are fixed at a point.	4. They revolve around the sun.
5. They are very big in size.	5. Planets are small as compared to

Question 3.
How many planets are there in our solar system?
Answer:
There are 8 planets in our solar system.

Question 4.
What is to be found between Mars and Jupiter?
Answer:
A belt of celestial bodies called as asteriods is found between the planets Mars and Jupiter.

Question 5.
Have you ever seen in the evening or in the pre-dawn hours a large celestial body with a long tail? What is it called?
Answer:
Yes, it is a comet – a large celestial body with a long tail. I have not seen it, but heard that in 1986 there was a Halley’s comet seen in the Indian sky.

Use your brain power!

Question 1.
Why do we see only one side of the moon?
Answer:
As the moon revolves around the earth it also rotates around itself. The moon takes 27.3 days to complete one revolution around the earth. It takes the moon the same time to complete one rotation around itself. Therefore, only one side of moon is visible.

Question 2.
Which planet has a day longer than its year?
Answer:
A planet’s day is how long it takes to complete one rotation on its own axis. Venus takes 243 earth days to complete one rotation because of its slow rotation around its axis. A year is the time taken by the planet to complete one revolution around the sun. Venus completes one revolution around the sun in 225 days. This makes a day longer than a year on Venus.

Answer in one sentence.

Question 1.
What is the Milky Way?
Answer:
Milky way is the galaxy in which our solar system is located.

Question 2.
What is a galaxy?
Answer:
A group of innumerable stars and their planetary systems are together known as galaxy.

Question 3.
What does the Universe include?
Answer:
The universe includes innumerable galaxies, the space between them and also energy.

Question 4.
What different colours do the stars radiate?
Answer:
The stars radiate different colours such as blue, white, yellow and red.

Question 5.
Where are stars bom?
Answer:
The birth place of stars are the huge nebulae, made of dust particles and gases.

Question 6.
What is the surface temperature of the sun?
Answer:
The surface temperature of the Sim is around 6,000°C.

Question 7.
What is the size of the sun?
Answer:
The size of the sun is so huge that around 13 lakh planets of the size of the earth can be easily placed within it.

Question 8.
How does the sun balance the other celestial bodies?
Answer:
Due to the gravitational force of the sun, the celestial bodies in the solar system revolve around it.

Question 9.
How does the sun move in the Milky Way?
Answer:
The sun rotates around its axis and while doing so, it revolves around the centre of the Milky Way taking the solar system along with it.

Question 10.
Which planet doesn’t have atmosphere?
Answer:
Mercury doesn’t have atmosphere.

Question 11.
How much time does the earth take to complete one rotation and one revolution?
Answer:
The earth completes one rotation in 24 hrs and one revolution in 365 days i.e. 1 year.

Question 12.
Which planets have rings around them?
Answer:
Jupiter, Saturn, Uranus, Neptune have rings around them.

Question 13.
Which planet do not have rings around them?
Answer:
Mercury, Venus, Earth and Mars do not have rings around them.

Question 14.
State two properties of planet Mercury.
Answer:
Mercury is the closet planet to the Sim. Mercury is the fastest moving planet.

Question 15.
When is the Mercury visible to us?
Answer:
Mercury is visible in the morning and in the evening if it is away from the sun.

Question 16.
What is seen on the surface of the mercury?
Answer:
A number of depressions which are actually caused by meteoric falls are seen on the surface of mercury.

Question 17.
When is Venus seen in the sky?
Answer:
Venus is seen in the sky in the east before the sunrise and in the west after the sunset. It rotates around itself from east to west.

Question 18.
How does earth protect us from harmful rays of Sun?
Answer:
As the earth is a magnet there is a magnetic field around the earth. It diverts the harmful rays from the sun towards the polar regions of the earth.

Question 19.
What is Olympus Mons?
Answer:
Olympus Mons is the highest and longest mountain in the solar system located on Mars.

Question 20.
Which is the largest planet of the solar system?
Answer:
The Jupiter is the largest planet of the solar system.

Question 21.
Why is Saturn considered a peculiar planet?
Answer:
Saturn considered a peculiar planet because of the rings around it.

Question 22.
How is the axis of Uranus?
Answer:
Uranus axis is so greatly inclined that it appears as if it is rolling along on its axis.

Question 23.
How are seasons on Neptune?
Answer:
The seasons on Neptune last for about 41 years.

Question 24.
What is a satellite?
Answer:
The celestial bodies that revolve around a planet , without independently revolving around the sun are called Satellite.

Question 25.
What is an Asteroid?
Answer:
A great number of small sized bodies could not turn into planets when the solar system was formed, but continued to revolve around the sun. This bodies are known as asteroids.

Question 26.
What is a Dwarf Planet?
Answer:
A small sized celestial body that revolves independently around the sun is called the dwarf planet.

Question 27.
What is a comet?
Answer:
A comet is a celestial body that revolves around sun. Comets are formed out of ice and dust particles.

Question 28.
What are meteors?
Answer:
Meteors are rocky pieces originating from the asteroids belt.

Question 29.
What are meteorites?
Answer:
Meteors which do not bum completely and fall to the surface of the earth are called meteorites.

Give reasons for the following.

Question 1.
Comets came to be called ‘dirty snowballs’.
Answer:
Comets consist of an icy cluster of various constituents like dust particles. Hence it is called dirty snowballs.

Question 2.
Comets are visible when they are close.
Answer:
Comets are formed out of ice and dust particles. They appear like points when they are far away from the sun, but when they are close to the sun they become easily visible to us because of the shorter distance and the heat of the sun.

Question 3.
Comets appear to have a long feathery tail.
Answer:
Comets are made up of frozen matter and dust particles. When they are close to the sun this frozen matter gets converted into gas due to the solar heat. These gases get thrown in a direction away from the sun. As a result comets appear to have a long feathery tail.

Question 4.
Pluto is called as a dwarf planet.
Answer:
Pluto is a small sized celestial body that revolves independently around the sun.

Question 5.
Moon is a satellite of the earth.
Answer:
Moon revolves around the earth without independently revolving around the sun. Hence moon is a satellite of the earth.

Question 6.
Mars is called the Red Planet.
Answer:
As the soil on the Mars contains iron its colour is reddish. Hence Mars is also called the RedPlanet.

Question 7.
Jupiter is called the Stormy Planet.
Answer:
Jupiter revolves around itself with a great speed. Hence Jupiter is called the Stormy planet.

Question 8.
Uranus appears rolling along on its orbit.
Answer:
Uranus axis is so greatly inclined that it , appears as if it is rolling along on its orbit.

Question 9.
Saturn is considered to be a peculiar planet.
Answer:

1. Saturn is considered as peculiar planet because of its rings around it.
2. Though its mass is 95 times that of the earth, its density is very low.
3. If it were dropped into a large sea enough to hold it, it would float in it.