DELHI PUBLIC SCHOOL TAPIVII LEARNING PARTNERSHIP Geogrpahy CW 4 Answer Key

5(a)Writing Task: Answer the following questions in your Geography notebook

1.Describe structure of atmosphere with the help of diagram(5 marks)

Ans: The atmosphere is divided into 5 layers..They are

a. Troposphere:

Its average height is 13 km

The air which living beings breathe exists here

All the weather phenomena like winds, rainfall , fog and hailstrom etc occur in this layer.

b. stratosphere

It extends up to height of 50 kms

It is almost free from clouds

No weather phenomenon occur in this layer making conditions .

Stratosphere contains a layer of ozone gas

It protects living beings from the harmful effect of the sun rays

Mesosphere

It extends upto a height of 80 kms

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Meteorites burn up in this layer on entering from the space

It lies above the stratosphere

Thermosphere

In thermosphere temperature rises very rapidly with increasing heihgt

Inosphere is a part of this layer

It extends between 80-400 kms.

2. Write difference between weather and climate

Weather is the day-to-day state of the atmosphere in a region and its short-term (minutes to weeks) variations,

Measured for short term

Weather includes sunshine, rain, cloud cover, winds, hail, snow, sleet, freezing rain, flooding,

whereas climate is defined as statistical weather information that describes the variation of weather at a given place for a specified interval.

Measured over a long period

Climate may include precipitation, temperature, humidity, sunshine, wind velocity,

[Time: 30 minutes MI: Verbal, Logical RBT: Understanding]

1. Writing Task : Read the lesson 4, discuss and complete textual exercise given on pp 27 - 28 in Geography textbook.

1. Answer the following questions.(i) What is atmosphere?

Ans: The earth is surrounded by a huge blanket of air called atmosphere.

(ii) Which two gases make the bulk of the atmosphere?

Ans: Nitrogen and oxygen make the bulk of the atmosphere.

(iii) Which gas creates green house effect in the atmosphere?

Ans: Carbon dioxide creates the greenhouse effect in the atmosphere.

(iv) What is weather?

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Ans: Weather is short-term state of the atmosphere whether it is hot or cold, wet or dry. It is the hour to hour, day to day condition of the atmosphere.

(v) Name three types of rainfall?Ans:Three types of rainfall are:(i) Convectional rainfall(ii) Orographic rainfall(iii) Cyclonic rainfall

(vi) What is air pressure?The pressure exerted by the weight of air on the surface of the earth is called air pressure.

2. Tick the correct answer.(i) Which of the following gases protects us from harmful sun rays?    (a) Carbon dioxide           (b) Nitrogen            (c) Ozone✓ (c) Ozone

(ii) The most important layer of the atmosphere is   (a) Troposphere            (b) Thermosphere             (c) Mesosphere

✓ (a) Troposphere

(iii) Which of the following layers of the atmosphere is free from clouds?      (a) Troposphere          (b) Stratosphere           (c) Mesosphere

(b) Stratosphere

(iv) As we go up the layers of the atmosphere, the pressure   (a) Increases            (b) Decreases             (c) Remains the same✓ (b) Decreases

(v) When precipitation comes down to the earth in the liquid form, it is called    (a) Cloud          (b) Rain        (c) Snow✓ (b) Rain

3. Match the following.(i) Trade Winds (a) Incoming solar energy(ii) Loo (b) Seasonal wind(iii) Monsoon (c) Horizontal movement of Air(iv) Wind (d) Layer of ozone gas- (e) Permanent wind- (f) Local wind

Answer

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(i) Trade Winds (e) Permanent wind(ii) Loo (f) Local wind(iii) Monsoon (b) Seasonal wind(iv) Wind (c) Horizontal movement of Air

Give reasons.(i) Wet clothes take longer time to dry on a humid day?

Ans: In humid day, the humidity is very high that is the level water vapour in atmosphere is high. Due to this, air is not able carry away more water vapour with it and thus the clothes take longer time to dry on a humid day.

ii) Amount of insolation decreases from equator towards poles?Ans:Insolation is the incoming solar energy intercepted by the earth. Sunlight falls almost vertically on the equator whereas it falls at some angle on the poles. Due to this, amount of insolation decreases from equator towards poles.

[Time: 30 minutes MI: Verbal; Logical; Intrapersonal RBT: Understanding

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