Class 9 MAHARASHTRA STATE TEXTBOOK BUREAU Solutions Social Studies Chapter 4 - Exogenetic Processes Part-2
Exogenetic Processes Part-2 Exercise 39
Solution 1(1)
Correct
Solution 1(2)
Incorrect. The work of winds is more prominent than other agents of erosion in desert regions.
Solution 1(3)
Incorrect. The groundwater work is powerful in the area with hard rocks.
Solution 1(4)
Correct
Solution 2(1)
Incorrect. The ice on the base of the glacier moves faster than the ice on the lateral side.
Solution 2(2)
Incorrect. The depositional work by rivers happens because of the length of the rivers, volume of water, amount of sediments, the slope of the river and the earth's surface.
Solution 2(3)
Correct
Solution 2(4)
Incorrect. The speed of the glacier is much more in the middle than on both banks of the glacier.
Solution 3
1. Deposition-V shaped valley
V shaped valley is formed due to the erosional work of rivers.
Solution 4
- V shaped valley
- Stalactite and Stalagmite
- Moraines
Solution 5
Solution 6(1)
Landforms formed as a result of the erosional work of the rivers:
- Gorges: it is a deep and a narrow valley. The slopes of gorges are steep and almost vertical. 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 bank and a narrow bed.
- V shaped valleys: These are formed due to erosional work of rivers. A V-shaped river valley is formed near the origin of the river or in its upper course.
- Waterfalls: Waterfalls occur due to sudden descent or break in the water flow. This may be due to steepness of the rocks, sudden earth movements, etc.
Solution 6(2)
- 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.
Solution 6(3)
Landforms that are produced by the depositional work of the sea waves are:
- Beaches: Beaches are composed of deposited sediments including sand, rocks, shells, algae, or pebbles brought in by the sea waves.
- Sandbars: Sand gets deposited along the sides of headlands. The deposited sand comes into the sea at some distance away from the beach. This is called sand bars.
- Lagoons: The brackish water separated from the seawater by sand bars and lying in the areas between the coast and bars is called a lagoon.
Solution 6(4)
Types of moraines are:
Ground moraines are the material deposited at the base of a glacier.
Terminal moraines are found at the terminus or the end point reached by a glacier.
Lateral moraines are found deposited along the sides of the glacier.
Medial moraines are found at the junction between two glaciers.
