Exercises Questions with Answers

Evaluation

I. Choose the correct answer

1. ____________ is a deposition of river sediments along the foot-hills.

a) Plunge pool

b) Alluvial fan

c) Flood plain

d) Delta

Answer: b. Alluvia fan

2. Courtallam falls is located across the____________ river.

a) Cauvery

b) Pennar

c) Chittar

d) Vaigai

Answer: c. Chittar

3. The landform created by glacial deposition is

a) Cirque

b) Arete

c) Moraine

d) Tarn lake

Answer: c. Moraine

4. Large deposits of loess are found in

a) USA

b) India

c) China

d) Brazil

Answer: c. China

5. ____________ are not associated with wave erosion

a) Cliff

b) Sea arch

c) Stack

d) Beaches

Answer: d. Beaches

II. Fill in the blanks

1. The process of breaking and crumbling of rocks is Weathering.

2. The place where the river joins a lake or a sea is known as River mouth.

3. Inselbergs are found in the Kalahari desert in South Africa.

4. A cirque is known as Kar in Germany.

5. The first longest beach in the world is Miami beach.

III. Match the following

1. Breaking and crumbling of  rocks – - Glacier

2. Abandoned meander loops - Barchans

3. Large body of moving ice - Lagoon

4. Crescent shaped sand dunes - Weathering

5. Vembanad lake - Oxbow lake

Answer: 1) Weathering 2) Oxbow lake 3) Glacier 4) Barchans 5) Lagoon

1. Breaking and crumbling of rocks : Weathering

2. Abandoned meander loops : Oxbow lake

3. Large body of moving ice : Glacier

4. Crescent shaped sand dunes : Barchans

5. Vembanad lake : Lagoon

IV. Consider the following statement and tick

(✔) the appropriate answer

1. Assertion (A): The deltas are formed near the mouth of the river.

Reason (R) : The velocity of the river becomes slow when it approaches the sea.

a) Both A and R are correct

b) A is correct and R is wrong

c) A is wrong and R is correct

d) Both A and R are wrong

Answer: a) Both A and R are correct

2. Assertion (A): Sea arches in turn become Sea Stacks.

Reason (R) : Sea Stacks are the results of wave deposition.

a) Both A and R are correct

b) A is correct and R is wrong

c) A is wrong and R is correct

d) Both A and R are wrong

Answer: b) A is correct and R is wrong

V. Answer the following

1. Define erosion.

Erosion is the wearing away of the landscape by different agents like water, wind, ice and sea waves. The eroded material is carried away by water, wind, etc. and eventually deposited. This process of erosion and deposition create different landforms on the surface of the earth.

2. What is a plunge pool?

Plunge pool is a hollow feature at the base of a waterfall which is formed by cavitation.

3. How are Ox – bow lakes formed?

Due to continuous erosion and deposition along the sides of the meander, the ends of the meander loop comes closer and closer. In due course of time the meander loop cuts off from the river and forms a cut-off lake, also called an Ox-bow lake.

4. Name the major landforms formed by glacial erosion.

Cirruc, Tam lake, Aretes, U shaped Valley.

5. Give a note on Mushroom rocks.

In deserts we can see rocks in the shape of a mushroom, commonly called mushroom rocks.

6. What is a lagoon? Give an example.

Lagoon is a shallow stretch of water partially or completely separated from the sea. E.g. Chilka lake in Odisha, Pulicat lake in Tamil Nadu and Andhra Pradesh and Vembanad lake in Kerala are the famous lagoons in India.

VI. Distinguish the following

1. Tributary and Distributary

Tributary

A stream or river that flows into and joins a main river.

Distributary

A stream that branches off and flows away from a main stream.

2. ‘V’ shaped valley and ‘U’ shaped valley

V Shaped Valley

The running water in the river erodes the landscape which creates a steep sided valley like the letter 'V’ known as V shaped Valley.

U Shaped Valley

U shaped valley is found beneath the glaciers which is deepened and widened by the lateral and vertical erosion. The material carried by the glacier such as rocks - big and small, sand and silt get deposited.

3. Continental glacier and Mountain glacier

Continental glacier

The glacier covering vast areas of a continent with thick ice sheets.

E.g. Antarctica, Greenland.

Mountain glacier

Mountain glacier is a stream of ice flowing along a valley. It usually follows former river courses and are banded by steep sides.

E.g: The Himalayas and the Alps.

VII. Give Reason

1. The ends of the meander loops come closer and closer.

Due to continuous erosion and deposition along the sides of the meander the ends come closer and closer.

2. Flood plains are very fertile.

As the river floods, it deposits layers of fine soil and other material called sediments along its banks. This leads to the formation of a flat fertile floodplain.

3. Sea caves are turn into stacks.

Erosion breaks the roof and only walls are left. These wall like features are called stacks.

VIII. Answer in a paragraph

1. Explain different landforms produced by river erosion.

The running water in the river erodes the landscape, which creates a steep-sided valley like the letter 'V' known as 'V' shaped valley.

Falling of river water over a vertical step in the river bed is called waterfall. It is formed when the soft rocks are removed by erosion. E.g. Courtrallam falls across the river Chittar in Tamil Nadu.

The highest waterfall is Angel Falls of Venezuela in South America. The other waterfalls are Nigara Falls located on the border between Canada and USA in North America and Victoria Falls on the borders of Zambia and Zimbabwe in Africa.

2. Describe the landforms associated with wind.

Winds erode the lower section of the rock more than the upper part. Therefore, such rocks have narrower base and wider top. An isolated residual hill, standing like a pillar with rounded tops is called Inselberg. E.g. Inselberg in the Kalahari Desert of South Africa.

When the wind blows, it lifts and transports sand from one place to another. When it stops blowing the sand falls and gets deposited in low hill - like structures. These are called sand dunes. The crescent shaped sand dunes are called Barchans.

3. How are aretes formed?

When two adjacent cirques erode towards each other, the previously rounded landscape is transformed into a narrow rocky, steep - sided ridge called Aretes.

Activity

1. Fill in the corresponding columns with reference to the landform features given below

[Barchan, ‘V’ Shaped valley, Cliff, Arete, Inselberg, Moraine, Alluvial fan, Lagoon]

2. Crossword Puzzle

Across

1. Place of origin of the river.

3. Arm chair shaped glacial landform

6. Glacial Depositional feature

7. Vertical drop of water

Down

2. Lagoon in Tamil Nadu

4. Loops along the river course

5. Wave depositional feature

3. Identify any one of the following features near your home town and write a note on them.

1. Hill

2. Waterfall

3. River (or) stream

4. Beach.