Class 9

Balbharti Maharashtra State Board Class 9 Geography Solutions Chapter 4 Exogenetic Movements Part 2, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 Geography Solutions Chapter 4 Exogenetic Movements Part 2

Class 9 Geography Chapter 4 Exogenetic Movements Part 2 Textbook Questions and Answers

1. Rewrite the correct statement:

Question 1.
The temperature range helps the wind in its work.
Answer:
Correct.

Question 2.
River’s work is more prominent than other agents of erosion in desert regions.
Answer:
Incorrect. Work of wind is more prominent in desert regions than other agents of erosion.

Question 3.
The work of groundwater is effective in the area with soft rocks.
Answer:
Correct.

2. Correct and rewrite the incorrect statements:

Question 1.
The ice on the lateral side of the glacier moves faster than the ice at the base.
Answer:
Incorrect. The ice on the base of the glacier moves faster than the ice on the lateral side.

Question 2.
The depositional work by rivers happens because of gentle slope, reduced speed and transported sediments.
Answer:
Correct.

Question 3.
A river flows at a faster speed than the glacier.
Answer:
Correct.

Question 4.
The speed of the glacier is more on both the banks than in the middle.
Answer:
Correct.

3. Identify the wrong pair

Question 1.
Deposition – V-shaped valley
Answer:
Wrong pair.
Correct pair is – Erosion – V-shaped valley

Question 2.
Transport – Ripple Marks
Answer:
Transport – Ripple Marks

Question 3.
Erosion – Mushroom Rocks
Answer:
Erosion – Mushroom Rocks

4. Identify and name the landforms in the following diagrams :

Answer:
(i) V-shaped valley
(ii) Gorge (Canyon)
(iii) Delta

5. Complete the following table by classifying the landforms according to their agents of erosion.
(waterfall, delta, cirque, arête, barchans, moraine, pothole, mushroom rock, sinkholes, beach, pillars, lagoons)
Rivers Wind Glacier Sea Waves Groundwater
Answer:

Rivers	Wind	Glacier	Sea waves	Ground Water
Waterfall	Barchans	Cirque	Beach	Sinkholes
Delta	Mushroom rock	Aretes	Lagoons	Pillars
Pothole		Moraine

6. Answer the following questions in brief.

Question 1.
List the landforms that are a result of the erosional work of the rivers.
Answer:
Gorges (canyons), V-shaped valleys and waterfalls are the result of the erosional work of the rivers.
(i) ‘V’ Shaped Valley:

• A ‘V shaped valley is formed due to the erosional work of a river.
• Over a period of time, the amount of load in the flow starts increasing.
• More and more energy of the river gets consumed in transporting the material.
• As a result, there is less erosion of the bed. The erosion along the banks and the slopes of the valley increases.
• Hence, the slopes recedes and the valley with near-vertical sides becomes wider, resembling the letter ‘V’.

(ii) Gorge:

• A gorge is found in the upper course of the river.
• It is a deep and narrow valley with steep sides.
• In mountainous areas, the river flows with great speed. Therefore, the bed of the river gets eroded more than its banks, giving rise to a gorge that has a steep banks and a narrow bed.

(iii) Waterfall:

• Waterfalls are formed as a result of the erosional work of a river.
• Water flowing over a hilly region cascades down a cliff, forming a waterfall.
• In the areas, where the hard and soft rocks are next to each other, the soft rocks are eroded faster than the hard ones. A difference in the height along the river bed leads to the formation of a waterfall.

Question 2.
Which agent is responsible for the formation of stalactites and stalagmites and where are they formed?
Answer:

• The work of groundwater is responsible for the formation of stalactites and stalagmites.
• In areas of limestone, the alkaline water seeps through the roof of the limestone caves.
• When this water evaporates, minerals get deposited at the bottom and at the top of the limestone caves.
• This leads to formation of stalactites and stalagmites.

Question 3.
List the landforms that are produced by the depositional work of the sea waves
Answer:
The landforms like beaches, sand bar, lagoons are formed due to depositional work of the sea waves.
(i) Beach:

• Large amount of sediments come from the landward side in areas between two adjoining headlands.
• Moreover, as these areas are shallow, the velocity of the waves decreases.
• As a result, the sediments that come from the land, as well as those coming from the deep sea, get deposited in this area.
• Predominantly fine sand gets settled along the coast.
• Such sandy deposits along the coasts are called beaches.

(ii) Lagoon:

• The brackish water separated from the seawater by sand bars and lying in the areas between the coast and bars is called a lagoon.
• As the waters are separated from the open sea, large waves are not generated.
• These lagoons run parallel to the sea coast.

(iii) Sand bars:

• Sand gets deposited along the sides of the headlands.
• The deposition extends parallel to the coast from one headland to the next.
• Over a period of time, these deposits extend over long distances forming bars that protrude into the water at some distance away from the beach.
• These are known as ‘sand bars’, Sometimes, the eroded material from the’ beach, gives rise to the sand bars.

Question 4.
Name the types of moraines.
Answer:
The glaciers carry sediments with them. These sediments are called moraines. Depending ond the location of the deposits, moraines can be divided into 4 types: ground moraines, lateral moraines, medial moraines and terminal moraines.

• The material deposited at the base of a glacier is called ground moraine.
• The material deposited along the banks of a glacier is called Lateral moraine.
• After the confluence of two glaciers, the moraine deposited in the central part of the glacier is known as medial moraine. It is formed out of . the side moraine of the inner banks of the two glaciers.
• At the end where a glacier turns into a stream, huge quantity of moraine is deposited. The stream of water is unable to carry the moraine further. As the deposited moraine is at the terminal part of a glacier, it is called terminal moraine.

7. Observe the following picture carefully. Identify the landforms formed by different agents of erosion. Number them with a pencil here and write their names in the sequence in your notebook.

(i)

Answer:
Depositional work of river

(ii)

Answer:
Depositional work of river

(iii)

Answer:
Erosional work of river

(iv)

Answer:
Depositional work of river

(2) Some pictures of the landforms formed by glaciers3 are given below. Write the function because of which they have been formed.

(i)

Answer:
Erosional work of glacier

(ii)

Answer:
Erosional work of glacier

(iii)

Answer:
Depositional work of glacier

(iv)

Answer:
Depositional work of glacier

(v)

Answer:
Erosional work of glacier

(vi)

Answer:
Erosional work of glacier

(vii)

Answer:
Depositional work of glacier

(3) Some pictures of the Iandforms produced by the work of the winds are given below. See the pictures and write in the box whether they have been formed by erosion or deposition.

(i)

Answer:
Erosional work of wind

(ii)

Answer:
Depositional work of wind

(iii)

Answer:
Depositional work of wind

(iv)

Answer:
Depositional work of wind

(v)

Answer:
Erosional work of wind

(vi)

Answer:
Erosional work of wind

(4) Some pictures of the landforms produced by the work of the sea waves are given below. See the pictures and write in the box whether they have been formed by erosion or deposition.

With the help of internet, obtain information regarding the places along the Konkan coast where you will find the landforms formed by sea waves.

(i)

Answer:
Erosional work of sea waves.

(ii)

Answer:
Depositional work of sea waves

(iii)

Answer:
Erosional work of sea waves.

(iv)

Answer:
Erosional work of sea waves.

(v)

Answer:
Erosional work of sea waves.

(vi)

Answer:
Depositional work of sea waves.

(vii)

Answer:
Depositional work of sea waves.

(5) See the pictures of the landforms produced by the work of groundwater. Write in the box below them whether they are formed through the work of erosion or deposition.

(i)

Answer:
Erosional work of ground water

(ii)

Answer:
Depositional work of ground water

Class 9 Geography Chapter 4 Exogenetic Movements Part 2 Intext Questions and Answers

Draw a diagram showing landforms at the sea coast:
Answer:

Can You Tell?

Question 1.
How will you differentiate between a rill, gully, stream and a river?
Answer:
The smallest natural flow of rain water is a rill. Many rills come together to form a gully. Many gullies come together and form a stream. Many streams come together and form a river. Thus we can see that rills, gullies, streams nad rivers are the various forms of flowing water in increasing order of their size.

Question 2.
What is a river?
Answer:
Running water flows naturally in a direction according to gravity along the slope, making its own way. This is called a flow of water when many such flows of water come together a river is formed.

Question 3.
Where can you see the work by glaciers in India?
Answer:
Glaciers can be seen in the Himalayan region in India.

Question 4.
In which natural region can you see the work of glaciers at the sea level?
Answer:
We can see the work of glacier at sea level in the Polar regions (Antarctica).

Question 5.
Where will you find the landforms formed by sea waves along the Konkan coast?
Answer:
Along the Konkan coast, landforms formed by sea waves can be found at Harihareshwar, Bhagwatibandar, Shrivardhan, Ratnagiri and Sindhudurg.

Think about it.

Question 1.
There are many creeks found in the coastal areas of Konkan but no delta, why?
Answer:
The Konkan coast has an indented (broken) coastline. Hence many creeks are found here. Many small seasonal rivers originate in the steep western side of the Western Ghats. As the rivers flow through the steep slopes their velocity increases. So, there is very little erosion done by them. Due to the narrow width of the Konkan coast, the rivers cover a short distance and drain in the Arabian sea. Thus they do not form estuaries rather than deltas.

Question 2.
Can you see a glacier moving just as you can observe the movement of river water?
Answer:
No

Question 3.
Ramu has to dig a well in his farm. But he is in a dilemma as to which season should he dig it so that there is water supply for a longer time. What will you suggest to Ramu?
Answer:
Ramu should dig a well during the summer season. A deep well can be dug during the summer season. This will ensure water supply not only during the monsoon and winter season but also during the next summer season.

Question 4.
Which agent has more kinetic energy of all-wind, river or glacier?
Answer:
Glacier is the agent of erosion which has the most kinetic energy of all. The glacier is a mixture of heavy soil and rock particles which are flowing. Thus it has both weight and movement.

Find out.

Question 1.
Is there any lake found near the meanders of the river? Obtain information about them.
Answer:

• Ox-Bow lakes are usually found near the meanders of a river.
• Wherever the river changes its direction, erosion takes place along the outer banks.
• If these conditions occur again and again, the river develops a zigzag path.
• Such a zigzag path is called a meandering path (course) and each loop along the path is called meander.
• When the turns in the course become acute, the limbs of a turn come very close.
• During flood, as the force of water increases, the river skips the meandering path and follows a straight path.
• The abandoned portion of the loop develops into a lake that is called an ‘ox-bow’ lake.

Question 2.
Where will you find mushroom rocks in the Deccan Plateau?
Answer:
Mushroom rocks can be found in the Hyderabad.

Question 3.
Can you find the work of wind near coastal areas? What landforms will be formed there?
Answer:
Yes, Ripple marks and sand mounds can be seen on the sand in the coastal regions.

Question 4.
Where are limestone caves, stalactites and stalagmites found in Maharashtra?
Answer:
Limestone caves, stalactites and stalagmites are found in Kanhur caves in the Ahmednagar district of Maharashtra.

Question 5.
Why are the landforms formed in limestone called Karst?
Answer:
A karst is an area of land formation created by eroding and dissolving portions of limestone or other soluble rock layers above or below the ground. According to the prevalent interpretation, the term is derived from the German name for the Karst region, a limestone plateau above the city of Trieste in the northern Adriatic.

Class 9 Geography Chapter 4 Exogenetic Movements Part 2 Additional Important Questions and Answers

Complete the statements by choosing the correct options.

Question 1.
The sediments are deposited at the foothills of the mountains in a triangular area forming an/a ………….. .
(a) alluvial fan
(b) yardang
(c) delta
(d) V-shaped valley
Answer:
(a) alluvial fan

Question 2.
The sediments carried by the glacier2 are called ………….. .
(a) sediments
(b) silt
(c) moraines
(d) alluvium
Answer:
(c) moraines

Question 3.
The erosional, transportation and depositional work of wind is more prominent in ………….. .
(a) polar regions
(b) deserts
(c) temperate regions
(d) grasslands
Answer:
(b) deserts

Question 4.
When many flows of water come together a …………… is formed.
(a) gorge
(b) river
(c) glacier
(d) canyon
Answer:
(b) river

Question 5.
The water which percolates through the porous rocks on the non-porous layer of rock is termed as ………….. .
(a) glacier
(b) flood leeves
(c) ground water
(d) surface water
Answer:
(c) ground water

Question 6.
…………… is formed due to depositional work of river.
(a) Delta
(b) Gorge
(c) V-shaped valley
(d) Canyon
Answer:
(a) Delta

Question 7.
In regions, where the temperatures are generally below freezing points, precipitation is in the form of ………….. .
(a) rainfall
(b) hail
(c) snowfall
(d) frost
Answer:
(c) snowfall

Question 8.
The erosional work of glacier forms ………….. .
(a) drumlins
(b) eskers
(c) cirques
(d) yardangs
Answer:
(c) cirques

Question 9.
The Jacobshavn Glacier in …………… is one of the fastest moving glaciers in the world.
(a) Finland
(b) Greenland
(c) Antarctica
(d) Himalayas
Answer:
(b) Greenland

Question 10.
The depositional work of ground water forms ………….. .
(a) limestone caves
(b) lagoons
(c) ripple marks
(d) seifs
Answer:
(a) limestone caves

Question 11.
Stalactites grow ………….. .
(a) downwards
(b) upwards
(c) sidewards
(d) fast
Answer:
(a) downwards

Question 12.
The ground water levels sink down in …………… season.
(a) summer
(b) winter
(c) rainy
(d) spring
Answer:
(a) summer

Question 13.
…………… is formed as a result of the depositional work of the sea waves.
(a) Sea cliff
(b) Lagoon
(c) Wave-cut platform
(d) Sea cave
Answer:
(b) Lagoon

Question 14.
The landforms developed in limestone areas are also called as …………… landforms.
(a) lime
(b) sinkhole
(c) krast
(d) coastal
Answer:
(c) krast

Match the Columns:

(1) River

Column A’		Column B’
(1)	Erosion	(a)	Ox-bow lake
(2)	Deposition	(b)	Meanders
		(c)	Yardangs

Answer:
(1 – b),
(2-a)

(2) Glacier

Column ‘A’		Column ‘B’
(1)	Erosion	(a)	Seif
(2)	Deposition	(b)	Eskers
		(c)	Cirque

Answer:
(1 – c),
(2 – b)

(3) Wind

Column ‘A’		Column B’
(1)	Erosion	(a)	Sand dunes
(2)	Deposition	(b)	Mushroom Rock
		(c)	Lagoon

Answer:
(1 – b),
(2 – a)

(4)

Column ‘A’		Column B’
(1)	Ground water	(a)	Delta region
(2)	Sea waves	(b)	Lagoon
		(c)	Sink holes

Answer:
(1 – c),
(2 – b)

(5)

Column ‘A’		Column B’
(1)	Stalactites & stalagmites	(a)	wind
(2)	Sand bar	(b)	ground water
		(c)	sea waves

Answer:
(1 – b),
(2 – c)

Answer in one sentence:

Question 1.
Name the agents of erosion.
Answer:
The agents of erosion are wind, rivers, glaciers, sea waves and ground water.

Question 2.
What factors does the work of a river depend on?
Answer:
The works of river depends on the nature of rock, the slope of land, velocity of the flow and the volume of water.

Question 3.
What are the important phases of a river’s work?
Answer:
The important phases of a river’s work are erosion, transportation and deposition.

Question 4.
What factors does the work of glaciers depend on?
Answer:
The work of glacier depends on the thickness of the accumulated ice, the temperature, and the slope of the land.

Question 5.
Which landforms are created due to the processes of erosion by the river?
Answer:
Landforms like gorges, V-shaped valleys, potholes and waterfalls are created due to the processes of erosion by the river.

Question 6.
Which landforms are formed mainly due to the transportational and depositional work of a river?
Answer:
Due to the transportational and depositional work of a river, meanders, ox-bow lakes, flood levees, flood plains and delta regions are formed.

Question 7.
Which landforms are created as a result of the erosional work of a glacier?
Answer:
The landforms such as a cirque, arete and matterhorn, U-shaped valley, hanging valleys, etc. are created as a result of the erosional work of a glacier.

Question 8.
Name the landforms formed by the depositional work of glaciers.
Answer:
The landforms formed by the depositional work of glaciers are drumlins, eskers etc.

Question 9.
Name the types of moraine.
Answer:
Ground moraine, lateral moraine, medial moraine and terminal moraine are the different types of moraine.

Question 10.
Which landforms are created as a result of the erosional work of the wind?
Answer:
The landforms like mushroom rocks, deflation hollows, yardangs etc. are created as a result of the erosional work of the wind.

Question 11.
Which landforms are created as a result of the transportation and depositional work of the wind?
Answer:
Sand dunes, barchans, seif, ripple marks, and loess plains are created as a result of transportation and depositional work of the wind.

Question 12.
Which landforms are produced as a result of the erosional work of sea waves?
Answer:
The landforms like sea cliffs, sea caves, wave-cut platforms, sea arches and sea stacks are produced as a result of the erosional work of sea waves.

Question 13.
Mention the landforms created due to the transportation and depositional work of sea waves.
Answer:
Beaches, sand bars and lagoons are created due to the transportation and depositional work of sea waves.

Fill the map with the given information and make a legend.

(1) Konkan Coast where work of sea waves can be seen
(2) Region in India where work of glaciers can be seen
(3) Desert region in India where work of wind can be seen
Answer:

Give geographical reasons:

Question 1.
Like the river, a glacier too carries out the work of erosion, transportation and deposition.
Answer:

• In regions, where the temperatures are generally below freezing points, precipitation is in the form of snowfall.
• Layers of snow accumulate on the earth’s surface because of snowfall.
• The heavy weight of these overlying layers makes the snow move along the slope.
• At the base of the layer, the snow starts melting because of the friction and the pressure from above. Glacier starts moving slowly along the slope.
• Thus like the river, a glacier too carries out the work of erosion, transportation and deposition.

Question 2.
Specific landforms are formed due to deposition by wind in arid and semi arid regions.
Answer:

• Sand particles that blow with the winds are of different shapes and sizes.?
• Those particles which are very fine are carried to larger distances while the larger ones get transported to shorter distances only.
• These sand particles get deposited in deserts and semi-arid climates.
• As a result, specific landforms are formed.
• Sand dunes, barchans, seifs, ripple marks, loess plains, etc. are formed by deposition by wind.

Question 3.
The work of sea waves cause different landforms.
Answer:

• In coastal areas, the sea waves carry out erosional, depositional and transportational work.
• Winds and tides cause the movements of sea water. As a result, waves come to the coast.
• Because of their hitting the rocks at the coasts, erosion of the rocks occurs.
• The landforms like wave cut platforms, sea caves, sea arches, sea cliffs, etc. are formed because of the erosional work of the waves.
• The landforms like beaches, sand bar, lagoons are formed due to depositional work of the sea waves.

Question 4.
In the desert, the work of wind is effective.
Answer:

• The work of wind is predominantly found in the hot desert and semi-arid regions.
• Hot deserts are found close to the Tropic of Cancer and Tropic of Capricorn.
• The average annual rainfall in the hot deserts is 250 mm or even less. Therefore, the vegetal cover is negligible.
• As there are no obstacles due to lack of vegetal cover, the work of wind is effective in the desert.

Question 5.
Glaciers have a low velocity.
Answer:

• In the high altitude areas and the areas of high elevation, the ice slides down the slope. Such a sliding mass of ice is called a glacier.
• As the ice moving in a glacier is in the solid state, its velocity is very low.
• The thickness of the accumulated ice, the temperature and the slope of the land are the factors that determine the velocity of the glacier.

Question 6.
The ground water level changes according to seasons.
Answer:

• The upper level of the stored ground water is called ground water level.
• It varies according to the slope of the land, porosity and compactness of the rocks and the rainfall in the region.
• Ground water level also changes according to season.
• In the rainy season, it is closer to the ground surface whereas during summer, it drops down deeper.

Identify the land forms made by waves and write their names in the given picture.

Answer:

• Wave-cut platform
• Lagoon
• Beach
• Sea cave
• Sea arch
• Sea stack
• Sea cliff

Write the name of the landforms with which the following diagrams are associated. Colour the eroded and the remaining part, if any, in the given diagrams.

Answer:
(a) Mushroom Rock
(b) Sand Dune (Barchan)
(c) Yardangs
(d) Seif (Sand Mounds)

Identify the landforms formed by groundwater in the given diagram.

Answer:
Stalactite and Stalagmite cave.

Answer the following questions in brief:

Question 1.
List the agents responsible for new landforms. i
Answer:
The agents – running water (river), glaciers, wind, sea waves and groundwater, – do the work of erosion, transportation and deposition. Because of these agents, the earth’s surface keeps undergoing changes and new landforms are formed.
(i) Running water (river):

• The river beds, as well as the banks of a river, are eroded due to the speedy flowing stream of water. The load that a river carries also erodes the banks and the bed of the river.
• The rocks, stones, sand, etc. collide with one another and break into fragments
• Different landforms like gorge, V-shaped valley, pothole and waterfall are formed due to the erosional work of a river.

(ii) Glaciers:

• As a glacier is nothing but a solid mass of ice, its velocity is very low. Nevertheless, the mass of water in the solid form is quite high. Therefore, glaciers cause a considerable amount of erosion.
• The glaciers erode the ice-clad base of the mountain slopes and the snow-clad sides of the mountains to a large extent.
• The Cirque, Arete and horn, U-Shaped valley and hanging valley are the landforms formed by the erosional work of a glacier.

(iii) Wind:

• The wind carries sand and pebbles.
• When they strike and scratch the rocks, the elevated and basal parts of the rocks get eroded.
• Due to the erosional processes of the wind, deflation hollows, mushroom rocks and yardangs3 are formed.

(iv) Sea waves:

• The basal portions of the headlands get severely eroded due to the continuous attack of sea waves. This leads to the erosion of the rocks on a large scale.
• Rocky coasts are formed where the headlands get severely eroded.
• Landforms such as sea cliffs, sea caves, wave- cut platforms, sea arches and sea stacks are formed due to the erosional work of sea waves.

(v) Groundwater:

• Soluble minerals in the rocks dissolve in water and they move along with the ground water. This process is called erosion by ground water.
• The work of ground water is predominant in the region where rock like limestone is found on a large scale.
• Limestone dissolves in carbonic acid. Carbonic acid is formed due to the presence of carbon? dioxide in ground water. This acid dissolves carbonates like limestone. Thus, chemical weathering takes place.
• The landforms like sinkholes and caves are the result of the erosional work of groundwater.

Question 2.
List the landforms that are produced due to deposition of sediments by rivers.
Answer:
Landforms like flood levees, flood plains, deltas are formed because of deposition of sediments,

1. Flood levees: When in flood, the river deposits ; the coarser material on the banks which in duecourse rises parallel to the banks of the river. These are called ‘flood levees’.
2. Flood plains: The finer silt deposited away from the banks during the flood form plains on ! either side of the river. They are called ‘flood plains’.
3. Delta: The continuous deposition leads to the formation of a plain in the shape of a triangle called delta. Extensive deltas have been formed ! at the mouth of rivers Ganga, Godavari, Kaveri.

Question 3.
Write in detail about the erosional and depositional work of wind.
Answer:
(i) Erosional work of winds:

• Wind carries small sand particles, small pebbles, etc. along with it.
• These particles cause erosion along rocks coming in the way due to friction.
• This leads to formation of mushroom rocks, deflation hollows, yardangs, etc.

(ii) Depositional work of winds:

• Sand particles that blow with the winds are of different shapes and sizes.
• Those particles which are very fine are carried to larger distances while the larger ones get transported to shorter distances only.
• These sand particles get deposited in deserts and semi-arid climates. As a result, specific landforms are formed.
• Sand dunes, barchans, seifs, ripple marks, loessplains, etc. are formed by deposition by wind.

Question 4.
Write in detail about the erosional and depositional work of sea waves.
Answer:
(i) Erosional work of sea waves:

• When the waves break at the coast, they bring with them water, transported stones, pebbles,sand particles, etc. This leads to the erosion of the coast.
• Because of the chemical and hydraulic action of the sea wave too, the erosion occurs. The landforms like wavecut platforms, sea caves, sea arches, sea cliffs, etc. are formed because of the erosional work of the waves.

(ii) Depositional work of sea waves:

• The eroded materials accumulate at the sea bed. Because of tides, they keep on moving towards the coast and away from the coast.
• They become fine because of attrition and hitting towards each other.
• Deposition of such materials occurs at the places where the effect of waves is less. The landforms like beaches, sand bar, lagoons are formed due to the depositional work of the sea waves.

Explain:

Question 1.
Erosional work of rivers
Answer:

• The rivers originate at a much higher altitude from the sea level.
• Here, the river flows at a great speed and therefore, its power to erode is great.
• The riverbed and the river banks get eroded because of the speedy flow of the river, sand particles, pebbles. Also, various tributaries join the main river.
• All these lead to the formation of gorges (canyons), V-shaped valleys and waterfalls.

Question 2.
Transportation and deposition by rivers
Answer:

• A river flows down the slope from a hilly region.
• At the foothills, the change in the slope causes deposition of coarse sediments.
• As these are deposited in a triangular shape, they form an alluvial fan. As the steepness of the slope decreases and the transport capacity of the river reduces, it starts flowing slowly.
• It bends (meanders) often in its way in an effort to cross even small obstacles.
• By the time the river reaches the sea, its riverbed becomes very wide and its speed becomes very slow.
• The sediments of the river get deposited in its bed and on its banks. The factors that determine the deposition of sediments are thelength of the rivers, volume of water, amountof sediments, and the slope of the river and the earth’s surface.
• Thus, landforms like flood levees, flood plains,deltas are formed because of deposition of sediments.

Question 3.
Erosion work by glaciers
Answer:

• Though the velocity of glaciers is less, the mass of the ice is more and hence the glacier erodes its own banks and its bed on a large scale.
• The erosional work of glaciers produces landforms like cirques, aretes, horns, U-shaped valleys, hanging valleys and roche moutonnees (or sheepbacks).

Question 4.
Transportation and deposition by glaciers
Answer:

• The glaciers carry sediments with them. These sediments are called moraines.
• Depending on the location of the deposits, moraines can be divided into 4 types: ground moraines, lateral moraines, medial moraines and terminal moraines.
• The depositional work of glacier produces landforms like drumlins, eskers, etc.

Question 5.
Erosional and depositional work of wind
Answer:

• Erosional work of wind: Wind carries smallsand particles, small pebbles, etc. along with I it. These particles cause erosion along rockscoming in the way due to friction.
• This leads to formation of mushroom rocks, deflation hollows, yardangs, etc.
• Depositional work of winds: Sand particles that blow with the winds are of different shapes and sizes.
• Those particles which are very fine are carried to larger distances while the larger ones get transported to shorter distances only.
• These sand particles get deposited in deserts ; and semi-arid climates. As a result, specific landforms are formed.
• Sand dunes, barchans, seifs, ripple marks, loess plains, etc. are formed by deposition by wind.

Question 6.
Erosional work of sea waves
Answer:

• When the waves break at the coast, they bring with them water, transported stones, pebbles, sand particles, etc.
• This leads to the erosion of the coast. Because of the chemical and hydraulic action of the sea wave too, the erosion occurs.
• The landforms like wave cut platforms, sea caves, sea arches, sea cliffs, etc. are formed because of the erosional work of the waves.

Question 7.
Depositional work of sea waves
Answer:

• The eroded materials accumulate at the sea bed.
• Because of tides, they keep on moving towards the coast and away from the coast.
• They become fine because of attrition and hitting towards each other. Deposition of such materials occurs at the places where the effect of waves is less.
• The landforms like beaches, sand bar, lagoons are formed due to depositional work.

Question 8.
Work of groundwater and landforms
Answer:

• The rainwater seeps below the earth’s surface through porous rocks or the cracks in the rocks.
• This water accumulates at the non-porous layer of the rock. This accumulated water is called groundwater.
• The soluble minerals in the water get dissolved and flow with the groundwater. This is the erosional work of the groundwater.
• When the groundwater evaporates or the volume of soluble minerals is more than the solubility of the groundwater, the deposition of dissolved materials starts.
• Landforms like sinkholes, limestone caves, stalactites and stalagmites are formed.
• Thus, the groundwater carries out the erosion, transportation and depositional work.

Question 9.
Groundwater table
Answer:

• The upper surface of the water accumulated below the ground is called the ground water table.
• Factors like seasons, porosity of rocks, amount of rainfall, etc. affect the level of water table.
• The water table is closer to the ground during rainy seasons while it is deeper in the summers.?

Balbharti Maharashtra State Board Class 9 History Solutions Chapter 2 India: Events After 1960 Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 History Solutions Chapter 2 India: Events After 1960

Class 9 History Chapter 2 India: Events After 1960 Textbook Questions and Answers

1. A. Choose the correct option from the given option and rewrite the statements:
Question 1.
The Prime Minister of India who took an initiative in resolving the question of the Tamil minority in Sri Lanka was
(a) Rajiv Gandhi
(b) Indira Gandhi
(c) H. D. Deve Gowda
(d) P. V. Narasimha Rao
Answer:
(a) Rajiv Gandhi

Question 2.
is the father of the Green Revolution in India.
(a) Dr. Verghese Kurien
(b) Homi Bhabha
(c) Dr. M. S. Swaminathan
(d) Dr. Norman Borlaug
Answer:
(c) Dr. M. S. Swaminathan

B. Identify and write the wrong pair in the following sets:

Question 1.
(1) Indira Gandhi – Emergency
(2) Rajiv Gandhi – Developments of Science and Technology
(3) P. V. Narasimha Rao – Economic improvements
(4) Chandrashekhar – Mandal Commission
Answer:
Chandrashekhar – Mandal Commission

Question 2A.
Based on the information in the chapter, prepare a chronological chart of Prime Ministers and their tenure.
Answer:

1. Pandit Jawaharlal Nehru -1947 to 1964
2. Lai Bahadur Shastri -1964 to 1966
3. Indira Gandhi -1966 to 1977
4. Morarji Desai -1977 to 1979
5. Charan Singh -1979 to 1980
6. Indira Gandhi -1980 to 1984
7. Rajiv Gandhi -1984 to 1989
8. Vishwanath Pratap Singh – 1989 to 1990
9. Chandra Shekhar -1990 to 1991
10. P. V. Narasimha Rao -1991 to 1996
11. Atal Bihari Vajpayee -1996
12. H.D. Deve Gowda -1996 to 1997
13. Inder Kumar Gujral -1997 to 1998
14. Atal Bihari Vajpayee – 1998 to 2004

2B. Write Short Notes on:

Question 1.
Globalisation
Answer:
(i) Globalisation brought about many changes in different fields like economy, politics, science and technology, society and culture.
(ii) India has emerged as an important country on the global scene in different spheres.
(iii) India is an important member of international organisations like G-20 and ‘BRICS’ (Brazil, Russia, India, China, South Africa).
(iv) India has experienced an important revolution in the field of telecommunication technology.
(v) Mobile phones, internet and the communication facilities based on satellite have spread all across the country.
(vi) It has resulted in a total transformation in the lifestyle of Indians and especially the youth.
(vii) These changes are visible from their dietary habits, clothing, language and beliefs.

Question 2.
White Revolution
Answer:
(i) White Revolution is a major event of India’s efforts towards self-reliance.
(ii) The experiment in co-operative dairy movement by Dr. Verghese Kurien led to the increase of milk production in India.
(iii) This is called as ‘White Revolution’.

3A. Give reasons:

Question 1.
The Morarji Desai government lasted for a short while.
Answer:
(i) On the backdrop of the emergency, many opposition parties came together and formed a party called the Janata Party.
(ii) The Congress party led by Indira Gandhi was roundly defeated by this newly formed ‘Janata Party’.
(iii) Morarji Desai became the Prime Minister, but under his leadership the Janata Party government couldn’t last long due to its internal differences.
(iv) Hence, the Morarji Desai government lasted for a short while.

Question 2.
The army had to be sent into the Golden Temple in Amritsar.
Answer:
(i) The Sikhs in Punjab demanded an independent state of Khalistan and began a movement which went on to become violent and destructive.
(ii) Pakistan had lent its support to this movement.
(iii) Some terrorists had allegedly taken shelter inside the Golden Temple at Amritsar, a holy shrine of the Sikhs in 1984.
(iv) Hence, the Indian army was sent into the Golden Temple in Amritsar to evict the terrorists who had taken shelter there.

Question 3.
The National Planning Commission was set up in India.
Answer:
(i) India wanted to acquire modernity and self-reliance by establishing industries.
(ii) India wanted to establish an economy based on social justice through planning.
(iii) For this, the National Planning Commission was established. This would coordinate development through the policy of Five Year Plans.

B. Answer the following questions in 25 to 30 words.

Question 1.
How was 1991 a year of important changes in the history of the world and of India?
Answer:
(i) The year 1991 is held to be very important in the history of the world as well as India.
(ii) The Soviet Union disintegrated into several different small countries and the Cold War came to an end.
(iii) During this period, the Ram Janmabhumi and Babri Mosque issue at Ayodhya came to the forefront.
(iv) In India, the Government under the leadership of Prime Minister P. V. Narasimha Rao initiated many changes in the Indian economy.
(v) These economic reforms are called as economic liberalisation. The Indian economy flourished as a result of the implementation of this policy.
(vi) Skilled Indian professionals helped reform the Indian economy. The field of information technology opened several avenues of employment in the country.
(vii) The changes after 1991 are also described as ‘globalisation’.

Question 2.
What are the characteristics of the Indian economy?
Answer:
(i) Right from independence, the modernisation of economy, economic self-sufficiency and social justice have been the characteristics of Indian economy.
(ii) India wanted to acquire modernity and self-reliance by establishing industries.
(iii) It wanted to establish an economy based on social justice through planning.
(iv) For this, the National Planning Commission was established that would coordinate development through the policy of Five Year Plans.

4. With the help of the information in the chapter, complete the list of the challenges before India and the strengths of India.
Question 1.

The Challenges In Front of India	Strengths
For Example: India-Pakistan war	Unity in diversity
…………………………..	……………………..
…………………………….	Nuclear preparedness
Separatism	……………………………..

Answer:

The Challenges In Front of India	Strengths
India-Pakistan war	Unity in diversity
Cross – Border Terrorism	Membership in G20 and BRICS
Corruption	Nuclear preparedness
Separatism	Establishment of National Planning Commission

Class 9 History Chapter 2 India: Events After 1960 Additional Important Questions and Answers

Choose the correct option from the given option and rewrite the statements:

Question 1.
The war between India and China took place in the year ________.
(a) 1952
(b) 1962
(c) 1972
(d) 1982
Answer:
(b) 1962

Question 2.
The Indo – China war was fought in the region of the _______ line.
(a)
MacMahon
(b) Kashmir
(c) St Lawrence
(d) Me Kinley
Answer:
MacMahon

Question 3.
Jawaharlal Nehru passed away in _________.
(a) 1944
(b) 1974
(c) 1984
(d) 1964
Answer:
(d) 1964

Question 4.
After Jawaharlal Nehru _______ became Prime Minister of India.
(a) Indira Gandhi
(b) Rajiv Gandhi
(c) Lal Bahadur Shastri
(d) Morarji Desai
Answer:
(c) Lal Bahadur Shastri

Question 5.
India and Pakistan went to war over the ________ issue in 1965.
(a) Kashmir
(b) Goa
(c) Hyderabad
(d) Kerala
Answer:
(a) Kashmir

Question 6.
The ______ mediated between the conflicting countries of India and Pakistan.
(a) Soviet Union
(b) USA
(c) Japan
(d) China
Answer:
(a) Soviet Union
(a) Soviet Union

Question 7.
_____ gave the slogan ‘Jai Jawan Jai Kisan’.
(a) Indira Gandhi
(b) Lai Bahadur Shastri
(c) Morarji Desai
(d) Rajiv Gandhi
Answer:
(b) Lai Bahadur Shastri

Question 8.
Lai Bahadur Shastri breathed his last at ______in 1966.
(a) Gorakhpur
(b) Kuala Lumpur
(c) Tashkent
(d) Varanasi
Answer:
(c) Tashkent

Question 9.
A Freedom Movement was led by Sheikh Mujibur Rahman and his organisation, ______.
(a) Mukti Bahini
(b) Bangla Bahini
(c) Aamar Sonar Bangla
(d) East Bengal Front
Answer:
(a) Mukti Bahini

Question 10.
The 1971 war between India and Pakistan led to the creation of an independent country called _______.
(a) Bangladesh
(b) Sri Lanka
(c) Sikkim
(d) Telangana
Answer:
(a) Bangladesh

Question 11.
India successfully carried out an underground test of an atomic device at ______ in Rajasthan.
(a) Dispur
(b) Mannapattam
(c) Sriharikota
(d) Pokhran
Answer:
(d) Pokhran

Question 12.
The ______ High Court gave the verdict in 1974 that Indira Gandhi the then Prime Minister had misused the government machinery during her election campaign.
(a) Allahabad
(b) Bombay
(c) Delhi
(d) Panaji
Answer:
(a) Allahabad

Question 13.
The situation set against Indira Gandhi became more complicated due to the movement led by _________.
(a) Dadabhai Naoroji
(b) Jayprakash Narayan
(c) G. D. Agarkar
(d) Ramanand Tirth
Answer:
(b) Jayprakash Narayan

Question 14.
The period of National Emergency lasted from _______ and after that general elections were conducted.
(a) 1922-24
(b) 1984-87
(c) 1975 – 77
(d) 1987-99
Answer:
(c) 1975 – 77

Question 15.
On the backdrop of the emergency, many opposition parties came together and formed a party called the _______.
(a) Republican Party
(b) Congress Party
(c) Janata Party
(d) Samaj Party
Answer:
(c) Janata Party

Question 16.
________ became Prime Minister on behalf of the Janata Party.
(a) Morarji Desai
(b) Indira Gandhi
(c) Rajiv Gandhi
(d) Lai Bahadur Shastri
Answer:
(a) Morarji Desai

Question 17.
The Sikhs in Punjab demanded an independent state of ______.
(a) Khalistan
(b) Pakistan
(c) Kazakhstan
(d) Baluchistan
Answer:
(a) Khalistan

Question 18.
______ had lent its support to the Khalistan movement.
(a) China
(b) Pakistan
(c) England
(d) Baluchistan
Answer:
(b) Pakistan

Question 19.
An organisation called ________ carried on a major movement in north-east India.
(a) United Liberation Front of Assam
(b) United Communist Group
(c) United India Front
(d) United Assam Federation
Answer:
(a) United Liberation Front of Assam

Question 20.
______ laid the foundation of Indian atomic power programme.
(a) Satish Dhawan
(b) Homi Bhabha
(c) A.P.J. Kalam
(d) Vikram Sarabhai
Answer:
(b) Homi Bhabha

Question 21.
______, a terrorist organisation assassinated Rajiv Gandhi.
(a) LTTE
(b) ASEAN
(c) LTEN
(d) LTTA
Answer:
(a) LTTE

Question 22.
India wanted to acquire modernity and self-reliance by establishing _______.
(a) Nuclear reactor
(b) Industries
(c) Electricity grids
(d) Telephonic infrastructure
Answer:
(b) Industries

Question 23.
The _______ government started economic reforms from 1991.
(a) Moraq’i Desai
(b) Indira Gandhi
(c) Narasimha Rao
(d) Lai Bahadur Shastri
Answer:
(c) Narasimha Rao

Question 24.
In 1999, ________ came to power under the flag of Bharatiya Janata Party.
(a) United Progressive Alliance
(b) League of Indian Politics
(c) India’s Administrative Assemblage
(d) National Democratic Alliance
Answer:
(d) National Democratic Alliance

Question 25.
________ is known as the father of the White Revolution.
(a) Dr. Verghese Kurien
(b) Dr. Dayaram Sahni
(c) Dr. Homi Bhabha
(d) Dr. M. S. Swaminathan
Answer:
(a) Dr. Verghese Kurien

Question 26.
In 1975, the first satellite, ________ was launched by India.
(a) Sputnik 1
(b) Apollo 1
(c) Aryabhatta
(d) Agni
Answer:
(c) Aryabhatta

Question 27.
The _________ Commission was set up in 1953 to make recommendations, so as to improve condition of the lower castes.
(a) Ganesh Agarkar
(b) Appasaheb Mayekar
(c) Tarabai Shinde
(d) Kakasaheb Kalelkar
Answer:
(d) Kakasaheb Kalelkar

Write Short Notes on:

Question 1.
Atomic Energy and Space Research.
Answer:
(i) Dr. Homi Bhabha laid the foundation of the Indian atomic power programme.
(ii) India insisted on using atomic energy for peaceful purposes like generation of electricity, pharmaceuticals and defence.
(iii) India has achieved considerable success in space technology as well. In 1975, the first satellite ‘Aryabhatta’ was launched.
(iv) Today, India has a successful space programme and many satellites have been launched under this programme. India has also made considerable advancement in the telecom sector.

Explain the statements with reason:

Question 1.
Globalisation brought about many changes in different fields.
Answer:
(i) India has emerged as an important country on the global scene in different spheres.
(ii) India is an important member of international organisations like G-20 and ‘BRICS’ (Brazil, Russia, India, China, and South Africa).
(iii) India has experienced an important revolution in the field of telecommunication technology.
(iv) Mobile phones, internet and the communication facilities based on satellite have spread all across the country.
(v) In the political field, India has demonstrated to the world how a stable democracy can function successfully.
(vi) All this has resulted in a total transformation in the lifestyle of Indians, especially the youth. These changes are visible from their dietary habits, clothing, language and beliefs.

Question 2.
There were several major changes in the social field in India for upliftment of women.
Answer:
(i) To promote the all-round development of women and children many constructive steps were taken.
(ii) A separate ‘Department of Women and. Child Development’ was created in 1985 under the Ministry of Human Resource Development.
(iii) Some laws were made to ensure social justice to women and to help the implementation of various schemes in this direction.
(iv) They include the Prohibition of Dowry Act, Equal Remuneration Act. As per the 73rd and 74th Constitution Amendments, seats are reserved for women in the local self¬government bodies.

Read the passage and answer the questions.

As a part of India’s policy to use atomic energy for peaceful purposes, India successfully carried out an underground test of an atomic device at Pokharan in Rajasthan in 1974. In 1975, the people of Sikkim voted for joining the Indian republic and Sikkim became a full-fledged State in the Indian federation. During this decade, the political situation in India grew unstable. The Allahabad High Court gave the verdict in 1974 that Indira Gandhi; the then Prime Minister had misused the government machinery during her election campaign. It led to nationwide strikes and protest. During this period, the situation became more complicated due to the movement led by Jayprakash Narayan. The situation of law and order in the country worsened and the government declared a state of National Emergency on the basis of the constitutional provisions relating to Emergency. During this turbulent period, the fundamental rights of Indian citizens were suspended. Due to the emergency, the Indian administration became disciplined, but the human rights were restricted. The period of national emergency lasted from 1975 to 1977 and after that general elections were conducted. On the backdrop of the emergency, many opposition parties came together and formed a party called the Janata Party. The Congress party led by Indira Gandhi was roundly defeated by this newly formed ‘Janata Party’. Morarji Desai became the Prime Minister, but under his leadership the Janata Party government couldn’t last long due to internal differences. Charan Singh succeeded him, but even his government was a short-lived one. Elections were conducted once again in 1980 and the Congress party under the leadership of Indira Gandhi came to power again.

Question 1.
Enlist incidents that culminated in Indira Gandhi’s rise to power post the verdict of Allahabad High Court.
Answer:
Following incidents paved the way of Indira Gandhi back to power:

• Allahabad High Court verdict against Indira Gandhi
• Nation – wide strikes and protest led by Jai Prakash Narayan
• Imposition of National Emergency (1975-77) fundamental rights suspended
• Opposition parties came together to form Janata Party.
• Short lived governments of Morarji Desai and Charan Singh.
• Elections conducted in 1980 – Congress back to power.

Question 2.
Which state became a constituent state of India in 1975?
Answer:
Sikkim voted to join the Indian Republic and it became a full – fledged state of Indian Republic in 1975.

Question 3.
Why do you think India conducted a nuclear test in Pokhran in 1974?
Answer:
India conducted Nuclear tests for two reasons:
(i) to keep Pakistan’s aggression under check post 1971 war.
(ii) To initiate peaceful and constructive use of atomic energy.

Answer the following questions in detail:

Question 1.
What were the contributions of Lai Bahadur Shastri?
Answer:
(i) Lai Bahadur Shastri succeeded Pandit Jawaharlal Nehru and became the next Prime Minister of India.
(ii) During his tenure, India and Pakistan went to war over the Kashmir issue in 1965.
(iii) The Soviet Union tried to mediate between the two countries.
(iv) Lai Bahadur Shastri gave the slogan ‘Jai Jawan Jai Kisan’ with which he highlighted the importance of Indian soldiers and Indian farmers.
(v) Lai Bahadur Shastri breathed his last at Tashkent in 1966.

Question 2.
Write a note on Rajiv Gandhi.
Answer:
(i) Right after Indira Gandhi’s assassination in 1984, Rajiv Gandhi became the Prime Minister of India.
(ii) He tried to make several reforms in the field of Indian economy and that of science and technology.
(iii) He took the lead in solving the issues of the Tamil minority in Sri Lanka. He promoted the idea of a united Sri Lanka with internal autonomy to the Tamil community, but his efforts in this regard proved to be in vain.
(iv) He faced a lot of criticism in the context of corruption that took place during a defence equipment deal, especially the purchase of long-range canons from a foreign company called Bofors.
(v) Political corruption became a crucial issue in the general elections that followed and the Congress party was defeated.
(vi) In 1991, during the election campaign, the terrorist organisation in Sri Lanka, Liberation Tigers of Tamil Eelam (LTTE), assassinated Rajiv Gandhi.

Question 3.
Write a note on Atal Bihari Vajpayee.
Answer:
(i) In 1999 the ‘National Democratic Alliance’ came to power under the flag of Bharatiya Janata Party and Atal Bihari Vajpayee became India’s Prime Minister (1998-2004).
(ii) Atal Bihari Vajpayee tried to establish a dialogue with Pakistan but was not successful.
(iii) India conducted a number of nuclear tests in 1998 and declared herself as an atomic power.
(iv) In 1999, there was another war between India and Pakistan in Kargil region over the Kashmir issue
(v) India defeated Pakistan in this war as well.

Question 4.
What is economic liberalisation? What are its benefits?
Answer:
(i) The Narasimha Rao Government started economic reforms from 1991. These economic reforms are known as economic liberalisation.
(ii) The Indian economy flourished as a result of the implementation of this policy.
(iii) The foreign investment in India increased. Skilled Indian professionals helped reform the Indian economy.
(iv) The field of information technology opened several avenues of employment in the country.
(v) The changes after 1991 are also described as ‘globalisation’.

Question 5.
What do you mean by
(i) Green Revolution and
(ii) White revolution?
Answer:
(i) Dr. M. S. Swaminathan is known as the father of the Green Revolution in 1965. He implemented new scientific agricultural techniques and increased the production of foodgrains.
(ii) The experiment in co-operative dairy movement by Dr. Verghese Kurien led to increase of milk production in India. This is called as ‘White Revolution’.

Question 6.
What is the progress of India in the fields of atomic energy and space research?
Answer:
(i) India had also made a lot of progress in the fields of atomic energy and space research.
(ii) Dr. Homi Bhabha laid the foundation of the Indian atomic power programme.
(iii) India insisted on using atomic energy for peaceful purposes like generation of electricity, pharmaceuticals and defence.
(iv) India has achieved considerable success in space technology as well. In 1975, the first satellite ‘Aryabhatta’ was launched.
(v) Today, India has a successful space programme and many satellites have been launched under this programme.
(vi) India has also made considerable advancement in the telecom sector.

Question 7.
Describe the changes in India due to globalisation.
Answer:
(i) Globalisation brought about many changes in different fields like economy, politics, science and technology and society and culture.
(ii) India has emerged as an important country on the global scene in different spheres. India is an important member of international organisations like G-20 and ‘BRICS’ (Brazil, Russia, India, China, and South Africa).
(iii) India has experienced an important revolution in the field of telecommunication technology. Mobile phones, internet and the communication facilities based on satellite have spread all across the country.
(iv) In the political field, India has demonstrated to the world how a stable democracy can function successfully.
(v) All this has resulted in a total transformation in the lifestyle of Indians and especially the
youth. These changes are visible from their dietary habits, clothing, language and beliefs.

Question 8.
How was an independent country of Bangladesh created?
Answer:
(i) Indira Gandhi became the Prime Minister of India in 1966.
(ii) During her tenure, Pakistan’s oppressive I policies in East Pakistan resulted in a big movement there. This movement was led by Sheikh Mujibur Rahman and his organisation, ‘Mukti Bahini.’
(iii) This crisis in East Pakistan affected India as well, because millions of refugees came to India.
(iv) The 1971 war between India and Pakistan led to the creation of an independent country called Bangladesh.

Question 9.
What policies were made to uplift the deprived sections of the society?
Answer:
(i) The ‘Kakasaheb Kalelkar Commission’ was set up in 1953 to make recommendations so as to improve their condition.
(ii) In 1978, a Commission was constituted under the chairmanship of B. P. Mandal to study the issue of the backward classes.
(iii) The policy of reservation was adopted in order to strengthen the representation of backward sections in various services and institutions.
(iv) The Government passed the Prevention of Atrocities Act in 1989 to enable those belonging to the Scheduled Castes and Tribes to live with dignity and respect, free from fear, violence and oppression of the upper classes.

Question 10.
Identify the picture and give relevant information.

Indira Gandhi became the Prime Minister of India in the year 1966.
Indira Gandhi’s strong leadership was prominent in the war between India and Pakistan in 1971.
The first atomic test at Pokharan was carried out under her leadership.
The Allahabad High Court gave the verdict in 1974, that Indira Gandhi had misused the government machinery during her election campaign.
She declared a’state of National Emergency in 1975.

Balbharti Maharashtra State Board Class 9 Geography Solutions Chapter 6 Properties of Sea Water Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 Geography Solutions Chapter 6 Properties of Sea Water

Class 9 Geography Chapter 6 Properties of Sea Water Textbook Questions and Answers

1. Tick the correct box according to the salinity of the ocean water ✓

Answer:
(a) Low
(b) Low
(c) High
(d) High
(e) Low
(f) High.

2. Give reasons.

(a) Salinity is low in the land-locked Baltic Sea.
Answer:

• The Baltic Sea lies in the temperate region.
• In temperate regions, the sunrays are slanting and therefore, the temperatures are lower.
• The supply of fresh water is also more, as numerous rivers empty their waters into the Baltic sea.
• Therefore, in spite of being landlocked, due to low rate of evaporation and ample supply of fresh water, the salinity of the Baltic Sea is low.

(b) There is higher salinity in the northern Red Sea while lower in the southern.
Answer:

• The Red Sea is one of the saltiest bodies of water in the world, owing to high evaporation.
• The salinity is 36%o in the southern part because of the effect of the Gulf of Aden.
• It reaches 41 %o in the northern part, owing mainly to the Gulf of Suez and the high evaporation as well as very little precipitation.
• Hence, there is more salinity in the northern Red Sea while lesser in the south.

(c) Oceans located at the same latitude do not have same salinity.
Answer:

• The salinity of the oceans depends on factors like rate of evaporation and supply of fresh water.
• In Oceans where rate of evaporation is more than the supply of fresh water, the salinity is higher.
• In Oceans where supply of freshwater exceeds the rate of evaporation, salinity is low.
• Salinity is not affected much in areas where supply of freshwater and the evaporation of water is low.
• Thus, oceans located on the same latitude do not have the same salinity.

(d) With increasing depth, the temperature of sea water decreases to a certain limit.
Answer:
With increasing depth, the temperature of sea water decreases to a certain limit because –

• While most of the sunrays radiate back from the surface of the sea, some of them penetrate to certain depths in the water.
• As a result, the intensity of sunrays decreases with the increasing depth.
• The temperature decreases up to 2000m depth.
• After 2000m, the temperature of the seawater is uniform everywhere.

(e) There are more salt-pans on the Western coast of India than its eastern coast.
Answer:

• The Arabian Sea lies lying to the west and Bay of Bengal lies to the east of India.
• Many large peninsular rivers drain their waters in the Bay of Bengal and on the contrary, only small seasonal coastal rivers drain in the Arabian Sea.
• Hence, the salinity of the eastern coast is 34%, while it is 35% in the Arabian Sea.
• Thus, there are more salt-pans on the Western coast of India than its Eastern coast.

(f) Salinity increases in the mid-latitudinal zones.
Answer:

• Mid-latitudinal zones lies between 25° to 35° north and south of the equator.
• In this zone, the rainfall is less and the supply of fresh water from rivers is also low.
• This region experiences high-temperature conditions which are marked by the presence of hot deserts of the world. These high-temperature conditions lead to a high rate of evaporation.
• Thus, the salinity of the seas is found to be higher in mid-latitudinal zones.

3. Answer the following questions.

(a) What are the factors affecting the salinity of the sea water?
Answer:

1. The uneven distribution of temperature on earth and uneven supply of freshwater affects the salinity of seawater.
2. In the tropical zone, temperature is higher. Rate of evaporation is also higher and therefore, the salinity is higher.
3. Around 5° N and S of the equator, in the equatorial calm belt, the sky is cloudy for a long period of time and convectional rainfall occurs every day.
4. Large rivers like Congo and Amazon in the equatorial regions meet the sea. Therefore, supply of freshwater is abundant, too. But because of higher temperatures, rate of evaporation is more and therefore, the seas in these areas are more saline.
5. In mid-latitudinal zones (25° to 35° N and S), rainfall is lesser and the supply of freshwater from rivers is also low. This zone has the hot deserts of the world. Thus, the salinity of the seas is found to be higher here.
6. In temperate regions, the sunrays are slanting and therefore, the temperatures are lower. Because of the melting of the snow, the supply of water is also more, and therefore, in this zone, salinity decreases with increasing latitudes.
7. In the polar areas, temperatures are very low. Evaporation is also very less in polar areas. So, salinity is low.
8. Landlocked seas have higher salinity than open seas as the rate of evaporation is more. There is a lack of supply of fresh water from large rivers. Thus, there is a difference in the salinities of open and closed seas.

(b) Explain the distribution of salinity around the Tropic of Cancer and tropic of Capricorn.
Answer:

• The uneven distribution of temperature on earth, and uneven supply of freshwater affects the salinity of sea water.
• Region, between the Tropic of Cancer and Tropic of Capricorn is called as the Tropical zone.
• In the tropical zone, temperature is higher.
• Hence, the rate of evaporation is also higher, and therefore, salinity is higher.

(c) What are the factors affecting the temperature of the sea water?
Answer:

1. Temperature is a major property of the sea water.
2. Sea water upto the depth of 500m is called as surface water. The surface temperature of the sea water is not uniform everywhere. This is dependent on different factors. .
3. Latitudinally, the surface temperature of the seawater decreases from the equatorial areas towards the poles.
4. The average temperature in equatorial areas is around 25° C, while it is about 2° C near the poles.
5. Besides this, cyclones, rainfall, sea waves, ocean currents, salinity, pollution, convectional currents, and seasons also affect the surface temperature.
6. Regions where cold ocean currents flow, the surface temperature of ocean water is less, while the regions where the warm currents move, the temperature increase.

(d) Explain the changes occurring in the temperature of sea water according to the depth.
Answer:

• While most of the sunrays radiate back from the surface of the sea, some of them penetrate to certain depths in the water.
• As a result, the intensity of sunrays decreases with the increasing depth.
• The temperature decreases up to 2000m depth.
• After 2000m, the temperature of the seawater is uniform everywhere.
• It is around 4°C everywhere from the equatorial regions to the polar areas.
• Temperature reduces only up to 4° C according to depth, and therefore, the water at greater depths does not freeze.
• The temperature of the seawater changes rapidly with depth at the equatorial areas. The difference in temperature is lesser in polar areas.
• There is also a difference in open seas and landlocked seas. In low latitudes, because the salinity of the landlocked seas is more, the temperature of the landlocked seas is higher than the open seas.

(e) Name the factors affecting salinity.
Answer:
Due to the sun’s heat, evaporation happens at a faster rate. Evaporated water turns into water vapour and reduces in quantity. But amount of salt remains the same in the remaining water and therefore the salinity of water increases.

• In seas where the rate of evaporation is high than the supply of fresh water, salinity is high.
• In seas where the supply of freshwater exceeds the rate of evaporation, salinity is low.
• Salinity is not affected much in seas where both the supply of freshwater and evaporation of water is low.

4. Explain how temperature affects the following.

(a) the density of sea water
Answer:

• If temperature reduces, density of water increases.
• Hence, cold water is denser than hot water.

(b) the salinity of sea water
Answer:

• If the salinity of water is high, the density of water increases.

Activity:

Complete the table showing the salinity of open and land-locked seas.

Answer:

Class 9 Geography Chapter 6 Properties of Sea Water Intext Questions and Answers

Observe the following Map and answer the questions:

Question 1.
What is the salinity around the tropics?
Answer:
The salinity around the tropics is 36%o.

Question 2.
Which region has the least salinity?
Answer:
The Bay of Bengal has the least salinity of 32%o.

Question 3.
Which ocean has salinity more than 37%o?
Answer:
Atlantic ocean has salinity of more than 37%o.

Question 4.
What are the reasons of differences in salinity on a global level?
Answer:
The uneven distribution of temperature on earth, and uneven supply of freshwater, etc. are the reasons for differences in salinity on a global level.

Observe the Graph and answer the questions:

Question 1.
What is the maximum temperature of seawater in equatorial areas? How much is this temperature at a depth of 500 m?
Answer:
The maximum temperature of sea water in equatorial areas is 18° C. The temperature at the depth of 500 m is 11° C.

Question 2.
What is the temperature of seawater at the sea level in the mid-latitudes?
Answer:
The temperature of seawater at the sea level in the mid-latitudes is 14° C approximately.

Question 3.
How much has this temperature changed at 1500 m depth?
Answer:
The temperature is about 5° C at the depth of 1500 m. Thus the temperature of sea water at mid-latitudes has changed from 14°C at the sea level to about 5°C at the depth of 1500 m i.e. temperature has changed (reduced) by 9°C.

Question 4.
What does the thermal graph for the high latitude say? What is its temperature at 500, 1000 and 1500 m depths?
Answer:
In high latitudes the temperature of sea water at all depths remains constant at 4° C.

Question 5.
After what depth does the seawater temperature remain stable everywhere?
Answer:
After 2000 m, the temperature of the sea water is uniform everywhere.

Question 6.
With increasing depth, what decreases: temperature, salinity or density?
Answer:
Temperature and salinity decreases with increasing depth.

Question 7.
After what depth does the change in these factor become almost zero?
Answer:
After the depth of 1000 m there is no change in all these factors.

Question 8.
Till what depth is the change in these factors higher?
Answer:
The higher change can be seen up to a depth of about 500m.

Question 9.
Explain the correlation between all the three factors.
Answer:
If the temperature is less, density is more. If the salinity is less, then density is also less. However temperature affects the density more as compared to the salinity. If the temperature is less, then the density is more despite less salinity.

Let’s Recall.

Question 1.
Which is the largest water storage of the world?
Answer:
Oceans are the largest water storage of the world.

Question 2.
Why is the seawater salty?
Answer:

• Salt in the ocean comes from rocks on land.
• Rivers carry dissolved salts to the ocean.
• Water evaporates from the oceans to fall again as rain and to feed the rivers, but the salts remain in the ocean.

Question 3.
What are the reasons for high salinity in the oceans?
Answer:
High rate of evaporation and low supply of fresh water leads to high salinity in the oceans:

Question 4.
How can we obtain the salts from the ocean water?
Answer:

• Sea water contains a large amount of common salt and the salts of other metals dissolved in it.
• Near the sea-shore, the sea water is collected in shallow pits (salt pans) and allowed to evaporate in the sunshine.
• In a few days, the water evaporates, leaving behind salt.
• The salt so obtained is collected and transported to factories, where it is purified and packed for consumption.

Question 5.
What is the use of the salts in the oceans to us?
Answer:

• The salts is used in the food we eat.
• It is used for making various chemicals and medicines.
• Salt is also used to preserve things for longer periods. It is also used in ice factories.

Can You Tell?

Question 1.
What is the difference in the temperatures of the land and the sea?
Answer:
During the daytime land is hotter than the sea whereas, during the night time land is cooler than the sea.

Question 2.
What would be the difference in the temperature of the seawater from the equatorial region to the polar areas?
Answer:
Latitudinally, the surface temperature of the seawater decreases from the equatorial areas towards the poles. The average temperature in equatorial areas is around 25° C while it is about 2° C near the poles.

Think about it.

Question 1.
If you think about India there is the Arabian sea to the west and the Bay of Bengal to the east. The salinity of the eastern coast is 34%o while it is 35%o in the Arabian sea. What could be the reason of higher salinity in the western coastal region?
Answer:
Many large peninsular rivers drain their waters in the Bay of Bengal and on the contrary only small seasonal coastal rivers drain in the Arabian sea. Hence the salinity of Arabian sea is more than the Bay of Bengal.

Try this.

Question 1.
In which container has the water increased or decreased?
Answer:

• The water has increased in the container which is in the classroom in which freshwater was added.
• The water has decreased in the container which was kept in the sun outside.

Question 2.
What could be the reasons behind the decrease or increase?
Answer:

• Since freshwater was added to one of the containers in the classroom the water level increased.
• The water has decreased in the container which was kept outside in the sun due to evaporation.

Question 3.
What could be the reason behind the low and high salinity of the water in the container?
Answer:

• In the container which as kept outside in the sun, due to high rate of evaporation, the salinity is high.
• As we kept on adding fresh water to the container kept in the classroom the salinity is low.

Class 9 Geography Chapter 6 Properties of Sea Water Additional Important Questions and Answers

Select the correct option:

Question 1.
The average temperature in equatorial areas is
(a) 25° C
(b) 35° C
(c) 15° C
(d) 5° C
Answer:
(a) 25°C

Question 2.
The average temperature in mid-latitudes is
(a) 25° C
(b) 10° C
(c) 16° C
(d) 5° C
Answer:
(c) 16°C

Question 3.
The average temperature near poles is about
(a) 10° C
(b) 20° C
(c) 15° C
(d) 2° C
Answer:
(d) 2°C

Question 4.
With the increasing depth of sea, the intensity of sunrays
(a) increases
(b) decreases
(c) remains constant
(d) is uneven
Answer:
(b) decreases

Question 5.
Seawater upto the depth of 500m is called
(a) ground water
(b) surface water
(c) deep water
(d) saline water
Answer:
(b) surface water

Question 6.
ocean is the most saline ocean in the world.
(a) Pacific
(b) Arctic
(c) Indian
(d) Atlantic
Answer:
(d) Atlantic

Question 7.
The sea lying on the border of Israel and Jordan has a salinity of %o.
(a) 37
(b) 50
(c) 256
(d) 332
Answer:
(d) 332

Question 8.
The buoyancy of the sea water increases because of its
(a) evaporation
(b) salinity
(c) density
(d) high temperature
Answer:
(b) salinity

Question 9.
has an altitude of – 400m.
(a) Baltic Sea
(b) Arabian Sea
(c) Dead Sea
(d) the Mediterranean Sea
Answer:
(c) Dead sea

Question 10.
act as temperature controllers at a global level.
(a) Ocean currents
(b) Sea breeze
(c) Land breeze
(d) Trade winds
Answer:
(a) Ocean currents

Question 11.
is a major porperty of the sea water.
(a) Temperature
(b) Uniform salinity
(c) Buoyancy
(d) Equal Density
Answer:
(a) Temperature

Question 12.
have higher salinity than open seas.
(a) Equatorial seas
(b) Landlocked seas
(c) Freshwater lakes
(d) Seas in polar regions
Answer:
(b) landlocked seas

Question 13.
Temperature decreases upto depth.
(a) 500 m
(b) 1000 m
(c) 1500 m
(d) 2000 m
Answer:
(d) 2000m

Question 14.
In regions where cold currents flow, the surface temperature of ocean water is
(a) high
(b) less
(c) uniform
(d) uneven
Answer:
(b) less

Question 15.
Temperature of seawater changes rapidly with depth in areas.
(a) equatorial
(b) mid latitudinal
(c) temperate
(d) polar
Answer:
(a) equatorial

Question 16.
In seas where the rate of evaporation is than the supply of fresh water, salinity is high.
(a) less
(b) high
(c) same
(d) low
Answer:
(b) high

Question 17.
The salinity of Bay of Bengal is than that of Arabian sea.
(a) less
(b) more
(c) same
(d) equal
Answer:
(a) less

Question 18.
In areas the salinity of sea water is low.
(a) equatorial
(b) mid-latitudinal
(c) temperate
(d) polar
Answer:
(d) polar

Question 19.
The salinity of Battic sea is %.
(a) 332
(b) 32
(c) 37
(d) 7
Answer:
(d) 7

Match the Column:

Column A	Column B
(1) Equatorial areas (2) Mid-latitudinal areas (3) Temperate regions	(a) Salinity of 332%o (b) Slanting sunrays, melting of snow (c) Cloudy sky and convectional rainfall (d) Hot deserts

Answer:
(1-c),
(2- d),
(3 – b)

Answer in one sentence:

Question 1.
What is the major property of seawater?
Answer:
Temperature is a major property of seawater.

Question 2.
What is the average surface temperature of seawater in equatorial areas, mid-latitudes & poles?
Answer:
The average surface temperature of seawater is equatorial areas is around 25°C in mid-latitude it is around 16°C & 2°C near the poles.

Question 3.
After what depth is the seawater temperature uniform everywhere?
Answer:
After 2000m, the temperature of seawater is uniform everywhere

Question 4.
Name the instruments used to measure salinity?
Answer:
Hydrometer, Refractometer and salinometer are used to measure salinity.

Question 5.
Which is the most saline ocean?
Answer:
The Atlantic ocean is the most saline ocean.

Give geographical reasons:

Question 1.
The climate of the earth gets affected by ocean currents.
Answer:

• The ocean currents are generated because of the difference in the properties of seawater.
• They act as temperature controllers at the global level.
• The distribution of temperature gets controlled due to the ocean currents.
• Thus, the climate of the earth gets affected by ocean currents.

Question 2.
Dead Sea has a salinity of 332%0.
Answer:

• The sea lying on the border of Israel and Jordan has a salinity of 332%0.
• The average salinity of ocean is 35%o.
• Jordan is the only large river meeting this sea.
• Low rainfall, low supply of freshwater and high evaporation is the reason of high salinity.

Question 3.
The surface temperature of the sea is not uniform everywhere.
Answer:

• The surface temperature of sea water is not uniform everywhere and it changes with latitudes.
• The surface temperature of the seawater decreases from the equatorial areas towards the poles.
• The average temperature in equatorial areas is around 25° C, it is 16° C in mid-latitudes while it is about 2° C near the poles.
• Besides this, cyclones, rainfall, sea waves, ocean currents, salinity, pollution, convergence flow, seasons, etc. also affect the surface temperature.
• Thus the surface temperature of the sea is not uniform everywhere.

Question 4.
The seas in equatorial calm belt are more saline.
Answer:

• Around 5° N and S of the equator, in the equatorial calm belt, the sky is cloudy for a long period of time and convectional rainfall occurs every day.
• Large rivers like Congo and Amazon in the equatorial regions meet the sea.
• Therefore, supply of freshwater abundant too.
• But because of higher temperatures, rate of evaporation is more and therefore, the seas in these areas are more saline.

Explain

Question 1.
Factors affecting surface water temperature
Answer:

• Temperature is a major property of the seawater. The surface temperature of the seawater is not uniform everywhere. This is dependent on different factors.
• Latitudinally, the surface temperature of the seawater decreases from the equatorial areas towards the poles.
• Besides this, cyclones, rainfall, sea waves, ocean currents, salinity, pollution, convergence flow and seasons also affect the surface temperature.
• Regions where cold ocean currents flow, the surface temperature of ocean water is less. The regions where the warm currents move, the temperature increase.

Question 2.
Density of sea water
Answer:

• Temperature and salinity are the two properties of sea water that control the density of the sea water.
• If temperature reduces, density of water increases.
• Cold water is denser, and so is saline water.
• As compared to salinity, temperature affects the density more. Hence, sometimes, more saline water has lower temperature at the surface.
• Sea water having higher temperature and low salinity, can have lower density.

Question 3.
Measurement of salinity of sea water.
Answer:

• The weight of all dissolved salts in water in ratio of parts per thousand of water is called the salinity of seawater.
• For example, if the weight of dissolved salts in 1000g (1 kg) of seawater is 40g, then the salinity is 40%o i.e. 40 per thousand parts.
• Hydrometer, refractometer and salinometer are also used to measure salinity.

Question 4.
Factors affecting salinity of sea water.
Answer:

Latitudes	Temperature / Rate of evaporation	Supply of fresh water	Salinity
Tropical Zone 5°N – 5°Sof equator	High	Abundant from (River Congo / Amazon)	High
Mid­latitudes (25° – 35° N and S)	High (hot desert are found here)	low	High
Temperate regions	Temperature is lower due to slanting sunrays	The supply of water is more due to melting snow	low
Polar regions	Very low	low	low

 

Balbharti Maharashtra State Board Class 9 Geography Solutions Chapter 3 Exogenetic Movements Part 1 Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 Geography Solutions Chapter 3 Exogenetic Movements Part 1

Class 9 Geography Chapter 3 Exogenetic Movements Part 1 Textbook Questions and Answers

1. Answer in brief.
(a) What is mechanical weathering?
Answer:

1. The disintegration of rocks without any change in their chemical composition is called mechanical weathering.
2. The minerals in the rocks expand because of heat and contract when the temperature decreases. Due to such continuous contracting and expansion, tension develops in the rock particles.
3. Each mineral reacts differently to the temperature; some minerals expand more, while others do not expand as much. Consequently, the tension formed in the rocks also increases and decreases. As a result, cracks develop in the rocks and they break.
4. In areas where the temperatures drop below 0°C for quite some time, the water accumulated in the cracks and crevices in the rocks freezes. Its volume increases which leads to tension in the rocks and they shatter.
5. When the alkaline water of the sea fills in the cracks of the rocks, the soluble minerals in the rock get dissolved leading to the formation of small holes in the rocks.
6. Because of the heat, this water turns into water vapour and only crystals of alkaline materials remain in the rocks. Crystals occupy more space which causes tension in the rock.
7. Sometimes the outer layers of the rocks exert pressure on the inner or lower layers. When this pressure ceases to exist, the lower or inner layers get freed from the pressure. This also leads to weathering.
8. In areas of heavy rainfall soaking of rock water also causes weathering of some rocks like sandstone and conglomerate. When water penetrates such rocks, the particles get loose and separate from the main rock.

(b) What are the main types of chemical weathering?
Answer:
The process of decomposition of rocks due to changes in their chemical composition is called chemical weathering.
Its main types are:
(i) Carbonation

• When the rain water mixes with the carbon dioxide in the atmosphere it leads to the formation of dilute carbonic acid.
• Many rocks like limestone get easily dissolved in such acids.

(ii) Solution

• Some minerals in the rock get dissolved in water.
• Because of this solution, alkalis in the rock dissolve and make them brittle.

(iii) Oxidation

• This process occurs in rocks which have iron present in them. The iron in the rock comes in contact with water and a chemical reaction takes place between iron and oxygen.
• Hence, a reddish coloured layer forms on the rocks. This is called rust.
• It occurs in rocks in areas with high rainfall.

(c) How does biological weathering occur?
Answer:

• It is the process by which rocks are broken into small fragments and fine particles due to the action of plants, animals and human beings.
• The roots of the plants enter the points and ! cracks of the rocks in search of moisture.
• As the roots grow bigger, they create tension in the rocks and start breaking them.
• Animals such as mice, rabbits and rats dig I holes, anthills etc. and weaken the rock, which makes them loose and break into pieces.
• Besides these, algae, moss1, lichen2, other flora grow in the rocks. They also help in weathering.
• Thus, the weathering caused by living organisms is called biological weathering,

(d) Distinguish between weathering and mass wasting.
Answer:

Weathering	Mass Wasting
(i) Breaking or weakening of rocks is called as weathering.	(i) When weathered rock material moves down the slopes due to gravity and accumulate near the foothills or gentle slopes, it is mass wasting.
(ii) Weathering is of three types – Mechanical, Chemical and Biological.	(ii) Mass wasting is of two types – Rapid and Slow.

2. Write whether the statements are true or false. Correct the incorrect ones.

(a) Climate affects earthquakes.
Answer:
False – Internal movements affect (leads to) earthquakes.

(b) Mechanical weathering is less effective in humid climates.
Answer:
True

(c) Mechanical weathering happens on a large scale in dry climates.
Answer:
True

(d) The breaking down of rocks into smaller particles is called weathering.
Answer:
True

(e) Lateritic rocks are formed through exfoliation.
Answer:
False – Lateritic rocks are formed due to oxidation.

3. Complete the flowchart below.

Answer:

4. Identify the type of weathering from the given description.

(a) Some animals live inside the grounds by making burrows.
(b) The rock rusts.
(c) Water which has accumulated in the crevices of the rocks freezes. Consequently, the rock breaks.
(d) The pipes supplying water in colder regions break.
(e) Sand formation occurs in deserts
Answer:
(a) Biological weathering
(b) Chemical weathering
(c) Mechanical weathering
(d) Mechanical weathering
(e) Mechanical weathering

Class 9 Geography Chapter 3 Exogenetic Movements Part 1 Intext Questions and Answers

Can You Tell?
(1) See the given pictures. Observe the physical appearance of the rocks in each picture. You can see that rocks are broken, fractured and have holes in them. In a picture you can also see that the statue has been deformed. Why are the rocks in such a condition? Think about them and briefly tell the reasons you can think of. Discuss the reasons. Check with the teachers if your reasons are relevant.
Answer:

• At some places the day temperatures are very high and the night temperatures are very low. In the given pictures the rocks may have broken due to temperature variation during day time and night time.
• In coastal areas when the sea waves hit the rocks, the rocks fracture and break down.
• Due to the roots of trees, and activities of burrowing animals like ant, rats etc. in the soft rocks, the rocks break down.
• The statues might be deformed due to heat and humidity.

Lets Recall

Question 1.
Have you seen the process of biological weathering3 around you?
Answer:
I have seen process of biological weathering3 around me. Many plants and trees have grown in an old dilapidated building which is located near my house. The roots of the trees have broken the walls and slabs of the building at many places.

Class 9 Geography Chapter 3 Exogenetic Movements Part 1 Additional Important Questions and Answers

Complete the statements choosing the correct option from the bracket:

Question 1.
…………………… is formed due to chemical precipitation between water and alkalis.
(a) Limestone
(b) Sandstone
(c) Coal
(d) Iron
Answer:
(a) Limestone

Question 2.
…………………… process occurs in rocks which have iron present in them.
(a) Shattering
(b) Oxidation
(c) Carbonation
(d) Granular
Answer:
(b) Oxidation

Question 3.
Sometimes the weathered materials do not move downward but sink ‘in situ’. This is called ………………….. .
(a) carbonation
(b) exfoliation
(c) precipitation
(d) slumping
Answer:
(d) slumping

Question 4.
periglacial regions along the slopes, small layers of soil accumulate because of the movement of soil. This is called ………………….. .
(a) soil erosion
(b) solifluction
(c) shattering
(d) block disintegration
Answer:
(b) solifluction

Question 5.
Biological weathering occurs because of ………………….. .
(a) high temperatures
(b) frost
(c) crystal growth
(d) living organisms
Answer:
(d) living organisms

Question 6.
come minerals in the rock get dissolved in the water and undergo chemical weathering. This process is called ………………….. .
(a) solution
(b) carbonation
(c) exfoliation
(d) precipitation
Answer:
(a) solution

Question 7.
When dilute carbonic acids reacts with the minerals in the rocks the process is called as ………………….. .
(a) carbonation
(b) exfoliation
(c) precipitation
(d) slumping
Answer:
(a) carbonation

Question 8.
When the outer layers of the rock fall apart from the main rock due to difference in temperatures, the process is called ………………….. .
(a) shattering
(b) oxidation
(c) exfoliation
(d) carbonation
Answer:
(c) exfoliation

Question 9.
…………………… is a universal solvent¹.
(a) Soil
(b) Water
(c) Carbon
(d) Oxygen
Answer:
(b) Water

Question 10.
Alkalis in the rock dissolve because of the solution and make them ………………….. .
(a) even
(b) sturdy
(c) brittle
(d) crusty
Answer:
(c) brittle

Match the Column:

I.

(I) Column ‘A’	Column ‘B’
(1) Mechanical weathering (2) Chemical weathering (3) Biological weathering	(a) burrowing (b) frost (c) carbonation (d) erosion

Answer:
(1-b),
(2- c),
(3 – a)

II.

Column ‘A’	Column ‘B’
(1) Oxidation (2) Slumping (3) Solifluction	(a) Mass movement occurring slowly (b) Carbon dioxide gets mixed with air (c) Chemical reaction between iron and oxygen (d) Weathered material which sink in situ

Answer:
(1 – c),
(2 – d),
(3 – a)

Answer in one sentence each;

Question 1.
What are the Exogenetic processes?
Answer:
Exogenetic processes are external processes 1 that occur on or above the earth’s surface, E.g. weathering, erosion, transportation, deposition etc.

Question 2.
Explain the Process of weathering
Answer:
Breaking or weakening of rocks is called as weathering.

Question 3.
What is Mechanical Weathering?
Answer:
The disintegration of rocks without any change in their chemical composition is called mechanical weathering.

Question 4.
What is Chemical Weathering (Salt Weathering)?
Answer:
The process of decomposition of rocks due to changes in their chemical composition is called chemical weathering.

Question 5.
What do you mean by Biological Weathering?
Answer:
The weathering process caused by human beings, animals and plants is called biological weathering.

Question 6.
What is Slumping?
Answer:
Sometimes the weathered materials do not move downward but sink ‘in situ’ (where they ! are). This is called slumping. ;

Question 7.
What is Solifluction?
Answer:
In periglacial regions along the slopes, small layers of soil accumulate because of the movement of soil. This is called solifluction.

Question 8.
Explain Granular Weathering.
Answer:
When water penetrates in rocks like sandstones and conglomerates1, the particles get loose and separate from the main rock. This is called granular weathering.

Question 9.
What is Block Disintegration?
Answer:
When water accumulates in wide points and big blocks of rocks separate from each other, this is called block disintegration.

Question 10.
What is Exfoliation?
Answer:
When the outer layer of the racks fall apart from the main rock due to temperature, the process is called exfoliation.

Question 11.
What does the term ‘diurnal Range’ mean
Answer:
The difference between the daily maximum and minimum temperature is diurnal Range.

Question 12.
What is Solution?
Answer:
The minerals in rocks which dissolve in water leads to the formation of solutions.

Question 13.
Name the two types of mass movements.
Answer:
The two types of mass movements are:
(a) Rapid Mass Movement and
(b) Show Mass movement.

Question 14.
What are the types of Mechanical weathering?
Answer:
The types of Mechanical weathering are
(a) Temperatures
(b) Frost
(c) Crystal growth
(d) Release of pressure and
(c) water

Question 15.
Types of chemical weathering.
Answer:
The types of chemical weathering are:
(a) Carbonation
(b) Solution and
(c) Oxidation

Question 16.
Where does Mechanical weathering occur?
Answer:
Mechanical weathering occurs mainly in the arid climates.

Question 17.
Chemical weathering can be seen in which climates?
Answer:
In humid conditions, one can see chemical weathering.

Write whether the statements are TRUE or FALSE. Correct the incorrect statements.

Question 1.
Soil creep is uncommon in areas with dry climates and gentle slopes.
Answer:
False – It is a common phenomenon in such areas.

Question 2.
Shattering is a type of mechanical weathering
Answer:
True.

Question 3.
Granular weathering occurs in areas of heavy rainfall.
Answer:
True.

Distinguish between:

Question 1.
Mechanical Weathering and Chemical Weathering.
Answer:

Mechanical Weathering	Chemical Weathering
(i) In this type of weathering, rocks get disintegrated but the chemical composition of the rocks does not change.	(i) It is a process where rocks get disintegrated and the chemical composition of the rocks change.
(ii) It is caused due to differences in the day and night temperature.	(ii) It is caused due to the reaction of oxygen, carbon dioxide and water with certain rock minerals.
(iii) It is more common in an extremely cold climates and hot dry desert climates.	(iii) It is more common in hot and humid climates.

Fill the map with the given information and make a legend.
(1) Area affected by a landslide (mudslide) in Maharashtra.
(2) Wadgaon Darya

Give geographical reasons:

Question 1.
Oxidation process occurs in heavy rainfall areas.
Answer:

• The oxidation process occurs in rocks which have iron present in them.
• The iron in the rock comes in contact with water and a chemical reaction takes place between iron and oxygen.
• A reddish coloured layer forms on the rocks.
• Thus, the oxidation process occurs in heavy rainfall areas.

Question 2.
Chemical weathering occurs in areas of heavy rainfall.
Answer:

• The rain water travels through the atmosphere before reaching the ground. Carbon dioxide in the air gets mixed in the water in this process.
• Dilute carbonic acid gets formed. Materials like limestone get easily dissolved in such acids leading to weathering of rocks.
• Some minerals in the rock gets dissolved in water. Limestone is formed due to chemical precipitation between water and alkalis.
  Similarly, because of the solution, alkalis in the rock dissolves and make them brittle.
• Oxidation process occurs in rocks which have iron present in them. The iron in the rock comes in contact with water and a chemical reaction takes place between iron and oxygen.
• Hence, a reddish coloured layer forms on the rocks. This is called rust.

Question 3.
Mechanical weathering3 takes place in the cold regions.
Answer:

• In the cold regions, the temperature drops below 0°C for a period of time.
• The water that has percolated through the cracks in the rocks freezes and turns into ice.
• Ice requires greater space than water. Tension is developed when the ice tries to acquire greater space.
• The continuous process of freezing and melting finally leads to the breaking of the rock mass.

Question 4.
Rapid mass movements occurs along the steep slopes.
Answer:

• A thick layer of weathered material forms on the steep slopes.
• When it rains in such areas, the rainwater penetrates the weathered materials and their weight increases.
• Due to this the weathered materials move very rapidly and come down the steep slopes.

Question 5.
Mechanical weathering is seen in areas where the diurnal range of temperature is high.
OR
Change in temperature leads to Mechanical weathering.
Answer:

• The minerals in the rocks expand because of heat and contract when the temperature decreases.
• Due to such continuous contracting and expanding, tension develops in the rock particles.
• Each mineral reacts differently to the temperature. Some minerals expand more, while others do not expand as much.
• Consequently, the tension formed in the rocks also increases and decreases. As a result, cracks develop in the rocks and they break.
• Thus in areas, where the diurnal range of temperature is higher, mechanical weathering is seen.

Question 6.
Water plays an important role in chemical weathering.
Answer:

• Rock is a mixture of many minerals.
• Since many things get dissolved easily in water, it is considered a universal solvent.
• The solubility1 of the solution increases because the matter gets dissolved in water.
• Water speeds up the process of carbonation, solution and oxidation. These processes lead to the weathering of rocks.
• Thus water plays an important role in chemical weathering.

Question 7.
Frost leads to mechanical weathering.
Answer:

• In areas where the temperatures drop below 0°C for quite some time, the water accumulated in the cracks and crevices in the rocks freezes.
• The volume of water increases on freezing.
• This leads to tension in the rocks and they shatter.
• In this way frost leads to mechanical weathering.

Answer in brief:

Question 1.
What is a mass movement? What are the types of mass movements?
Answer:
The weathered rock materials move along the slopes due to gravity and accumulate near the foothills or the gentler slopes. When the weathered particles move down due to gravity alone, the process is called mass movements.

Types of Mass movements:
(i) Rapid mass movements:

• A thick layer of weathered material forms on the slope. When it rains in such areas, the rain water penetrates the weathered materials and their weight increases.
• The weathered materials move very rapidly and come down the slope.
• Sometimes the weathered materials sink in situ. (Where they are)
• Rockfalls, landslides, land subsidence are ; termed as rapid mass movements.

(ii) Slower mass movements:

• Soil creep is the most common phenomenon in areas with dry climate and gentler slopes.
• In periglacial regions along the soil. This is called as solifluction.

Question 2.
How does external processes occur?
Answer:

• External processes occur because of the forces working on the earth’s surface.
• They are mainly solar energy, gravitational force and kinetic energy associated with the moving objects on the earth’s surface.

Question 3.
What is exfoliation?
Answer:

• In regions of high temperatures, the exposed part of the rock heats more while the inner part is comparatively cooler.
• As a result, the outer layers of the rocks fall apart from the main rock.
• This is called the exfoliation of the rock.

Question 4.
Explain the process of oxidation.
Answer:

• The oxidation process occurs in rocks which have iron present in them.
• The iron in the rock comes in contact with water and a chemical reaction takes place between iron and oxygen.
• Hence, a reddish coloured layer forms on the rocks. This is called rust.

Explain:

Question 1.
Block Disintegration
Answer:

• Sometimes both temperature and water are responsible for weathering.
• The difference in temperature cause contraction and expansion of minerals in the rocks. This leads to widening theoints or cracks in the rocks.
• Water accumulates in such wideouts and big blocks of rocks separate from each other.
• This is called Block Disintegration.

Question 2.
Carbonation
Answer:

• Carbonation is a type of chemical weathering.
• The rainwater travels through the atmosphere before reaching the ground.
• Carbon dioxide in the air gets mixed in the water in this process and dilute carbonic acid gets formed.
• For e.g Water + Carbon Dioxide = Carbonic Acid (H₂O +CO₂ = H₂CO₃)
• Materials like limestone get easily dissolved in such acids.

Question 3.
Solution
Answer:

• Some minerals in the rock get dissolved in water.
• Limestone is formed due to chemical precipitation between water and alkalis.
• At Wadgaon Darya in Ahmadnagar district, limestone gets precipitated chemically i.e. undergoes chemical weathering again.
• Similarly, because of solution, alkalis in the rock dissolve and make them brittle.

Question 4.
Make a record of few landslides that have occured in India and write about them briefly.
Answer:
Landslide is a rapid mass movement which is caused majorly due to heavy rains, floods, earthquakes etc. The following are some fatal landsides in India.

1. Guwahati landslide, Assam:- The landslide took place in the year 1948 due to heavy rains & over 500 people died in this landslide.
2. Darjeeling landslide, West Negal:- This landslide happened in the year of 1968. It was triggered by floods and thousands of people died due to this landslide.
3. Malpa landslide, Uttarkhand:- Consecutive landslides occured in August 1998 in village of Mapla due to which 380 people died as an entire village was destroyed in the landslide.
4. Kedarnath landslide, Uttarakhand:- This landslide took place onune 16, 2013 & was the result of Uttar Khand floods. Over 5700 people were reported dead and over 4200 villages were affected by floods and post-flood landslide.
5. Malin landslide, Maharashtra:- This landslide occured onuly 30, 2014, in a village in Malin. The landslide occured due to heavy rainfall and around 151 people died and 100 people went missing after the disaster.