Geography

Our Changing Earth

Question:

Answer the following questions briefly:
(i)  Why do the plated move?
(ii)  What are exogenic and endogenic force?
(iii) What is erosion?
(iv) How are flood plains formed?
(v) What are sand dunes?
(vi) How are beaches formed?
(vii) What are ox-bow lakes?

Answer:

(i) The plates move because of the movement of the molten magma inside the earth.
(ii) Exogenic forces. The forces that work on the surface of the earth are called as exogenic forces.
Endogenic forces. The forces that act in the interior of the earth are called as endogenic forces.
(iii) Erosion is the wearing away of the landscape by different agents like water, wind and ice.
(iv) 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 flood plains.
(v) Sand dunes are low hill-like structures formed by the deposition of sand in the deserts.
(vi) Beaches are formed when the sea waves deposit sediments along the shores of the sea.
(vii) 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 ox-bow lake.

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Our Changing Earth

Q 1.

Name some coastal landforms.

Q 2.

How do the lithospheric plates move?

Q 3.

Which earthquake is classified as a major earthquake?

Q 4.

What is a delta?

Q 5.

Name the two processes which wear away the landscape.

Q 6.

Answer the following questions briefly:
(i)  Why do the plated move?
(ii)  What are exogenic and endogenic force?
(iii) What is erosion?
(iv) How are flood plains formed?
(v) What are sand dunes?
(vi) How are beaches formed?
(vii) What are ox-bow lakes?

Q 7.

Define focus' and epicentre'. [Imp.]

Q 8.

Name the scale on which the magnitude of the earthquake is measured.

Q 9.

How are glacial moraines formed?

Q 10.

Give an account of the work of wind. [V. Imp.]

Q 11.

What does the process of erosion and deposition create?

Q 12.

Name the three types of earthquake waves.

Q 13.

What is a seismograph? [V. Imp.]

Q 14.

Give reasons:
(i) Some rocks have a shape of a mushroom.
(ii) Flood plains are very fertile.
(iii) Sea caves are turned into stacks.
(iv) Buddings collapse due to earthquakes.

Q 15.

Mention the work of ice.

Q 16.

Give an account of earthquake preparedness.

Q 17.

What is a volcano?

Q 18.

What do you know about the lithospheric plates?

Q 19.

What is earthquake? What are some common earthquake prediction methods?[V. Imp.]

Q 20.

Where is Victoria Falls located? [Imp.]

Q 21.

Name a few rivers of the world that form a delta?

Q 22.

Activity
Observe the photographs given below. These are various features made by a river. Identify them and also tell whether they are erosional or depositional or landforms formed by both.
ncert-solutions-for-class-7-geography-social-science-chapter-3-our-changing-earth-5.1

Q 23.

Explain the work of a river.