NCERT Solutions Class 7 Geography Chapter 3 Our Changing Earth
NCERT Solutions Class 7 Geography Chapter 3 Our Changing Earth: National Council of Educational Research and Training Class 7 Geography Chapter 3 Solutions – Our Changing Earth. NCERT Solutions Class 7 Geography Chapter 3 PDF Download.
NCERT Solutions Class 7 Social Science Geography Chapter 3: Overview
Board |
NCERT |
Class |
7 (Seven) |
Subject |
Social Science |
Book Name |
Geography |
Chapter |
03 (Three) |
Chapter Name |
Our Changing Earth |
Topic |
Exercise Solutions |
NCERT Solutions Class 7 Geography Chapter 3 – Our Changing Earth
1.) Answer the following questions.
(i) Why do the plates move?
Answer
The movement of the molten magma inside the earth cause the plates to move around a few millimeter each year.
(ii). What are exogenic and endogenic forces?
Answer
The movements of the earth are divided on the basis of the forces which cause them.
- The forces that work outside of the surface are called as Exogenic forces. Examples-Erosional and Depositional through River, Wind, sea-waves.
- The forces which act in the inside of the earth are called as Endogenic forces. Examples- Sudden forces like volcano , Earthquake.
(iii).What is erosion?
Answer
The process in which Earth landscapeare worn away and transported by different agents like water, wind and etc is called erosion.
(iv).How are flood plains formed?
Answer
When a river overflows it causes flooding in the surrounding area .This floods deposits a layer of fine soil and other material called sediments. Thus, forming a layer fertile soil called flood plains.
(v).What are sand dunes?
Answer
Generally in desert when the wind blows, it lifts and carrys and from one place to place. When it stops blowing the sand falls and gets deposited in low-hill like structures. These are called sand dunes.
(vi). How are beaches formed?
Answer
Beaches are formed when the sea waves deposit sediments along the seashores.
(vii) What are ox-bow lakes?
Answer
Due to Continuous erosion and deposition along the sides of the meander, the ends of the meander loop come closer and closer, By time the meander loop cuts off from the river and forms a cut-off lake also called an ox-bow lake.
Q 2.) Tick the correct answer.
(i) Which is not an erosional feature of sea waves?
(a) Cliff
(b) Beach
(c) Sea Cave
Answer
(b) Beach
Explanation: It is because they are formed due to the depositional activities of sea waves.
(ii).The depositional feature of a glacier is:
(a) Flood plain
(b) Beach
(c) Moraine
Answer
(c) Moraine
Explanation: Moraine means sediments, rocks, boulders, dirt and more carried and deposited by the Glacier
(iii).Which is caused by the sudden movements of the earth?
(a) Volcano
(b) Folding
(c) Flood plain
Answer
(a) Volcano
Explanation: It is because a volcanic eruption will cause a damageon the Earth’s Lithosphere.
(iv) Mushroom rocks are found in:
(a) Deserts
(b) River valley
(c) Glaciers
Answer
(a) Desert
Explanation: It is because in the desert erosion is carried out by wind This happens because the wind destroy lower part of a rocky outcrop quicker than its upper part.
(v).Ox bow lakes are found in:
(a) Glaciers
(b) River valleys
(c) Deserts
Answer
(b) River valleys
Explanation: It is because this lakes are made when the river divides into meanders which later separate from the source river to form a Ox bow lake.
3.) Match the following
(i) Glacier- (c) River of ice.
(ii) Meanders- (d) Rivers.
(iii) Beach- (a) Sea shore.
(iv) Sand dunes-(h) Deserts.
(v) Waterfall- (g) Hardbedrock.
(vi) Earthquake-(e) Vibrations of earth.