Class 7 Social Science Chapter 3 The Earth’s Surface and its Change Question Answer in English Medium to each chapter is provided in the list so that you can easily browse throughout different chapters SEBA Class 7 Social Science Chapter 3 The Earth’s Surface and its Change Notes and select need one.
Class 7 Social Science Chapter 3 The Earth’s Surface and its Change
Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given Geography, History, Political Science and Economics Assam Board Class 7 Social Science Chapter 3 The Earth’s Surface and its Change Solutions for All Subject, You can practice these here.
The Earth’s Surface and its Change
Chapter – 3
GEOGRAPHY
1. Write answers to the following (within 30 words)
(i) What do you mean by atmosphere?
Ans: The blanket of air surrounding the surface of our earth is called the atmosphere. All living beings inhabiting the earth depend on this atmosphere.
(ii) What is the yearly movement of plates?
Ans: An average rate of about 1.5 centimeters (0.6 inches) a year.
(iii) Write about temporary wind?
Ans: Temporary wind also known as gusts or sudden bursts of air can have a significant impact on our environment and daily activities.
(iv) What is sand dune?
Ans: When the wind blows, it carries and transports the sands from one place to another. In some areas when the velocity of wind decreases, the blown away sand gets deposited forming low hill like structure. These are called “sand dunes’.
(v) What is an Ox – bow lake?
Ans: Due to continuous erosion and deposition along the banks of the meander, the ends of the meander loop come closer and closer. In due course of time the meander loop cuts of from the river and forms a cut-off lake. It is called an Ox-bow lake.
2. Tick (✔) the correct answers:
(i) Which of the following gases protects us from the harmful rays of the sun?
(a) Carbondioxide.
(b) Nitrogen.
(c) Ozone.
Ans: (c) Ozone.
(ii) The deposit of glacier is called-
(a) Floodplain.
(b) Mushroom rock.
(c) Moraine.
Ans: (c) Moraine.
(iii) Which of the following is a Precipitation in the form of Water?
(a) Rain.
(b) Cloud.
(c) Ice.
Ans: (a) Rain.
(iv) The place where mushroom-shaped rocks are found is-
(a) Desert.
(b) River valleys.
(c) Floodplains.
Ans: (b) River valleys.
(v) The most important atmospheric layer for human being is –
(a) Mesosphere.
(b) Stratosphere.
(c) Troposphere.
Ans: (c) Troposphere.
(vi) The place where Ox-bow lakes are found is –
(a) Polar region.
(b) River valley.
(c) Desert.
Ans: (b) River valley.
3. Match the given items:
| (a) Trade wind | (a) Middle course of a river |
| (b) Glacier | (b) Local wind |
| (c) Loo | (c) Ozone layer |
| (d) Meandering course | (d) River of ice |
| (e) Stratosphere | (e) Regular wind |
Ans:
| (a) Trade wind | (e) Regular wind |
| (b) Glacier | (d) River of ice |
| (c) Loo | (b) Local wind |
| (d) Meandering course | (a) Middle course of a river |
| (e) Stratosphere | (c) Ozone layer |
4. Give reasons ( within 50 words):
(i) Wet clothes do not dry up easily in damp weather.
Ans: The humidity level in the atmosphere is already high, so it becomes difficult for moisture to change into vapour. Water vapour in the atmosphere is already heavy so when we try to dry clothes the evaporation process is slow but effective due to the presence of water vapour in the air.
(ii) The floods plains are very fertile.
Ans: At times the river overflows its banks. This leads to the flooding of the neighbouring areas. As it floods, it deposits layers of fine soil and other materials called ‘sediments’ along its banks. This leads to the formation of a flat fertile “Floodplain.”
(iii) Some desert rocks are mushroom – shaped.
Ans: The wind can blow away the fine lighter dust particles for long distance. But wind cannot blow away the sand particles for long distance. Of course the capability of erosion of such blowing sand particles at certain height is high. Thus, wind is an active agent of erosion and deposition in the desert. That is why one can see rocks with the shape of a ‘mushroom’ in the desert.
(iv) The polar regions are colder that the equatorial region.
Ans: In the equatorial region, tempera- ture is very high and hence always an area of low pressure is formed. The air pressure is measu- red with Barometer machine. The temperature of the Polar Regions is significantly colder than the equatorial regions because the sun’s rays are not directly at the poles.
