CBSE Class VII (7th) Geography -Chapter 3. Our Changing Earth -Solved Exercises
Question1.Answer the following questions.
Q(i).Why do the plates move?
Answer.The plates move due to endogenic forces in the interior of the earth.
Q(ii).What are exogenic and endogenic forces?
Answer.The forces that act in the interior of the earth are called endogenic forces. The forces that act on the earth’s surface are called exogenic forces.
Q(iii).What is erosion?
Answer. Erosion is the wearing away of the landscape by different agents like water, wind and ice.
Q(iv).How are flood plains formed?
Answer. When rivers outflow their banks, they cause flood in the neighbouring areas. The flood water takes away fine soil an other material and deposit them along the banks.
This deposition leads to the formation of flood plains.
Q(v) What are sand dunes?
Answer.Winds lift an carry sand from one place to another.When they stop blowing,sand falls and gets deposited in low hill-like structures called sand dunes.
Q(vi). What are ox-bow lakes?
Answer.When a river enters the plain,it forms a large bend which is cut-of stream in due course of time. The cutt of stream takes the form of a lake called ox-bow lake
Question 2. Tick the correct answer:
Q(i) Which is not an erosional feature of sea waves?
(a) Cliff. (b) Beach. (c)Sea cave.
Answer:(a)Cliff.
Q(ii) The depositional feature of a glacier is:
(a) Flood plain. (b) Beach. (c) Moraine
Answer:(c)Moraine
Q(iii) Which is caused by the sudden movement of the earth?
(a) Volcano. (b) Folding. (c) Flood plain.
Answer:(a)Volcano.
Q(iv) Mushroom rocks are found in:
(a) Deserts. (b) River valleys. (c) Glaciers.
Answer:(a)Deserts.
Q(v) Oxbow lakes are found in:
(a) Glaciers. (b) River valleys. (c) Deserts.
Answer:(b)River valleys.
Question3. Match the following:
Answer.
Q(i).Why do the plates move?
Answer.The plates move due to endogenic forces in the interior of the earth.
Q(ii).What are exogenic and endogenic forces?
Answer.The forces that act in the interior of the earth are called endogenic forces. The forces that act on the earth’s surface are called exogenic forces.
Q(iii).What is erosion?
Answer. Erosion is the wearing away of the landscape by different agents like water, wind and ice.
Q(iv).How are flood plains formed?
Answer. When rivers outflow their banks, they cause flood in the neighbouring areas. The flood water takes away fine soil an other material and deposit them along the banks.
This deposition leads to the formation of flood plains.
Q(v) What are sand dunes?
Answer.Winds lift an carry sand from one place to another.When they stop blowing,sand falls and gets deposited in low hill-like structures called sand dunes.
Q(vi). What are ox-bow lakes?
Answer.When a river enters the plain,it forms a large bend which is cut-of stream in due course of time. The cutt of stream takes the form of a lake called ox-bow lake
Question 2. Tick the correct answer:
Q(i) Which is not an erosional feature of sea waves?
(a) Cliff. (b) Beach. (c)Sea cave.
Answer:(a)Cliff.
Q(ii) The depositional feature of a glacier is:
(a) Flood plain. (b) Beach. (c) Moraine
Answer:(c)Moraine
Q(iii) Which is caused by the sudden movement of the earth?
(a) Volcano. (b) Folding. (c) Flood plain.
Answer:(a)Volcano.
Q(iv) Mushroom rocks are found in:
(a) Deserts. (b) River valleys. (c) Glaciers.
Answer:(a)Deserts.
Q(v) Oxbow lakes are found in:
(a) Glaciers. (b) River valleys. (c) Deserts.
Answer:(b)River valleys.
Question3. Match the following:
| 1 | Glacier . | (a) | Sea-shore. |
| 2 | Meanders. | (b) | River of ice. |
| 3 | Beach. | (c) | Rivers. |
| 4 | Sand dunes. | (d) | Vibrations of earth. |
| 5 | Waterfall. | (e) | Hard bed rock. |
| 6 | Earthquake. | (f) | Deserts. |
Answer.
| 1 | Glacier . | (b) | River of ice. |
| 2 | Meanders. | (c) | River . |
| 3 | Beach. | (a) | Sea-shore. |
| 4 | Sand dunes. | (f) | Deserts. |
| 5 | Waterfall. | (e) | Hard bed rock. |
| 6 | Earthquake. | (d) | Vibrations of earth. |
