NCERT Class 7 Geography Chapter 3 Question Answers from the chapter Our Changing Earth. NCERT Class 7 Geography Chapter 3 Question Answers include simplified and easy-to-understand solutions.
NCERT Class 7 Geography Chapter 3 Question Answers
1. Why do the plates move?
The plates move because of the movement of the molten magma inside the earth.
2. What are exogenic and endogenic forces?
The forces that work on the surface of the earth are called exogenic forces.
The forces that act in the interior of the earth are called endogenic forces.
3. What is erosion?
Erosion is the wearing away of the landscape by different agents like water, wind, and ice.
4. How are flood plains formed?
During floods, layers of fine soil and other material called sediments are deposited on the river bank. This leads to the formation of a flat fertile floodplain.
5. What are sand dunes?
Sand dunes are small hill-like structures formed by the deposition of sand in deserts.
6. How are beaches formed?
Beaches are formed when the sea waves deposit sediments along the shores of the sea.
7. What are ox-bow lakes?
When the meander loop is cut off from the main river, it forms a cut-off lake. As its shape is like an ox-bow, it is also known as an ox-bow lake.
NCERT Class 7 Geography Chapter 3 Question Answers – MCQs
1. Which is not an erosional feature of sea waves?
(c) Sea cave
2. The depositional feature of a glacier is
(a) Flood plain
3. Which is caused by the sudden movements of the Earth?
(c) Flood plain
4. Mushroom rocks are found In
(b) River valleys
5. Ox-bow lakes are found In
(b) River valleys
NCERT Class 7 Geography Chapter 3 Question Answers – Match the columns
|1. Glacier||c. River of Ice|
|2. Meanders||d. Rivers|
|3. Beach||a. Sea Shore|
|4. Sand Dunes||h. Deserts|
|5. Waterfall||g. Hard Bedrocks|
|6. Earthquake||e. Vibrations of Earth|
NCERT Class 7 Geography Chapter 3 Question Answers – Give Reasons
1. Some rocks have a shape of a mushroom.
In deserts, winds usually erode the lower section of the rock more than the upper part. Therefore, such rocks have a narrower base and wider top, which take the shape of a mushroom.
2. Flood plains are very fertile.
Flood plains are formed by the deposition of fine soil and other material called sediments on the river banks. As the soil and sediments are brought by floodwater, they are very fertile.
3. Sea caves are turned into stacks.
Sea waves strike at the rocks. As a result, cracks develop which become bigger over time, and hollow-like caves are formed on the rocks. They are called sea caves. These cavities become bigger and bigger and a time comes when only the roof of the caves remains to form sea arches. Further erosion breaks the roof and only walls are left. These wall-like features are called stacks. In this way, sea caves are turned into stacks.
4. Buddings collapse due to earthquakes.
Most of the buildings are not safe enough to resist the vibrations of earthquakes. They are not made earthquake-proof. They collapse tearing apart due to shallow foundations and a lack of adequate steel in the interior design.