9th Social Science Lesson 13
13] Lithosphere – II Exogenetic Processes
Book Back Questions with Answer and Do You Know Box Content
Do You Know?
The disintegrated rock materials, in due course of time, are weathered further, to form soil. Soil is a mixture of disintegrated rock material and decayed organic matter called humus.
The highest water falls in the world is Angel falls (979 m) in Venezuela.
Tributary: Small streams that join the main river. Eg. River Bhavani. Distributary: River channels that get separated from the main river. Eg. River Kollidam.
The Greek letter (∆) pronounced delta closely resembles the triangular delta of the river Nile. Sunderban Delta formed by the river Ganga-Brahmaputra is the largest delta in the world. The world’s best known geyser is the Old Faithful Geyser in the Yellowstone National Park in Wyoming, U.S.A.
The world’s largest oxbow lake is Lake Chicot is Arkansas of USA. Lake Kanwar in Bihar (India) is Asia’s largest fresh water ox how lake.
Karst Areas in India: Western Bihar – Guptadham caves; Uttarakhand – Robert cave and Tapkeshwar temple; Madhya Pradesh – Pandav caves Pachmari hills; Bastar district in Chattisgarh – Kutumsar; Andhra Pradesh (Visakhapatnam) – Borra Caves.
The World’s deepest sinkhole is China’s xianozhai Tienkang at 2172 feet. There are as many as 15000 Sinkholes in Illinois.
The thickest known deposit of loess is, 335 metre found in the loess plateau in China.
Choose the best answers:
1. The disintegration or decomposition of rocks is generally called as
2. The process of the levelling up of land by means of natural agents.
3. ______________ is seen in the lower course of the river.
(b) Alluvial fan
4. Karst topography is formed due to the action of
(c) Sea waves
(d) Ground Water
5. Which one of the following is not a depositional feature of a glacier?
6. Deposits of fine silt blown by wind is called as
7. Stacks are formed by ____________
(a) Wave erosion
(b) River erosion
(c) Glacial erosion
(d) Wind deposition
8. ______________ erosion is responsible for the formation of cirque.
(d) Underground water
Match the following:
1. Distributaries – Glacial action
2. Mushroom rock – Action of sea wave
3. Eskers – Lower course of river
4. Stalactites – Aeolian process
5. Cliff – Karst topography
Consider the following the statements and tick the appropriate answer:
1. i) ‘I’ Shaped valley is an erosional feature of the river.
ii) ‘U’ Shaped valley is an erosional feature of the glacier.
iii) ‘V’ Shaped valley is an erosional feature of the glacier.
(a) i, ii & iii are correct
(b) i & ii is correct
(c) i & iii is correct
(d) only iii is correct
2. Statement I: Running water is an important agent of gradation.
Statement II: The work of the river depends on the slop of land on which if flows.
(a) Statement I is false and II is true
(b) Statement I and II are false
(c) Statement I is true and II is false
(d) Statement I and II are true
3. Statement: Limestone regions have less underground water.
Reason: Water does not percolate through limestone.
(a) The statement is right reason is wrong.
(b) The statement is wrong reason is right.
(c) The statement and reason are wrong.
(d) The statement and reason are right.
Choose the correct answers:
1. Weathering 2. Gradation 3. Delta 4. Ground water 5. Cirque 6. Loess 7. Wave erosion 8. Glacial
Match the following:
1. Lower course of river 2. Aeolian process 3. Glacial action 4. Karst topography 5. Action of sea wave
Consider the following statements and choose the correct answer:
1. Statement i and ii is correct.
2. Statement I and II are true
3. The statement is right reason is wrong.