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Correct option is (a) solution

Correct option is (b) Water

Correct option is (c) brittle

In periglacial regions along the slopes, small layers of soil accumulate because of the movement of soil. This is called solifluction.

• 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.

When water penetrates in rocks like sandstones and conglomerates1, the particles get loose and separate from the main rock. This is called granular weathering.

• 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.

Sometimes the weathered materials do not move downward but sink ‘in situ’ (where they ! are). This is called slumping.

When water accumulates in wide points and big blocks of rocks separate from each other, this is called block disintegration.

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

The weathering process caused by human beings, animals and plants is called biological weathering

• 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.

When the outer layer of the racks fall apart from the main rock due to temperature, the process is called exfoliation.

The minerals in rocks which dissolve in water leads to the formation of solutions.

• 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.

In humid conditions, one can see chemical weathering.

Breaking or weakening of rocks is called as weathering.

The process of decomposition of rocks due to changes in their chemical composition is called chemical weathering.

Mechanical weathering occurs mainly in the arid climates.

The types of Mechanical weathering are 

(a) Temperatures 

(b) Frost 

(c) Crystal growth 

(d) Release of pressure and 

(e) water

The difference between the daily maximum and minimum temperature is diurnal Range.

• 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.

The disintegration of rocks without any change in their chemical composition is called mechanical weathering.

• 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.

• 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.

• 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 (H₂ O + CO₂ = H₂ CO₃ ) 
• Materials like limestone get easily dissolved in such acids.

• 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.

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.

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.

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.

The works of river depends on the nature of rock, the slope of land, velocity of the flow and the volume of water.

Correct answer is (c) krast

No 

Can you see a glacier moving just as you can observe the movement of river water.

Along the Konkan coast, landforms formed by sea waves can be found at Harihareshwar, Bhagwatibandar, Shrivardhan, Ratnagiri and Sindhudurg.

The agents of erosion are wind, rivers, glaciers, sea waves and ground water.

Correct answer is (a) downwards

Mushroom rocks can be found in the Hyderabad.

Ground moraine, lateral moraine, medial moraine and terminal moraine are the different types of moraine.

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.

Due to the transportational and depositional work of a river, meanders, ox-bow lakes, flood levees, flood plains and delta regions are formed.

Landforms like gorges, V-shaped valleys, potholes and waterfalls are created due to the processes of erosion by the river.

The important phases of a river’s work are erosion, transportation and deposition.

The landforms formed by the depositional work of glaciers are drumlins, eskers etc.

The work of glacier depends on the thickness of the accumulated ice, the temperature, and the slope of the land.

Correct answer is (b) Greenland

(i) Depositional work of river

(ii) Depositional work of river

(iii) Erosional work of river

(iv) Depositional work of river

The landforms like mushroom rocks, deflation hollows, yardangs etc. are created as a result of the erosional work of the wind.