Question 1

Tick the correct answer.The major constituent of atmosphere by percent is

Accepted Answer

The atmosphere is composed mainly of nitrogen and oxygen, which make up about 99 per cent of clean, dry air. Nitrogen 78 per cent, oxygen 21 per cent and other gases like carbondioxide, argon and others comprise 1 per cent by volume.

Question 2

State whether these sentences are true (T) or false (F).Air moves from low pressure to high pressure.

Accepted Answer

False,When warm air rises, cooler air will often move in to replace it, so wind often moves from areas where it's colder to areas where it's warmer. So in the northern hemisphere, winds blow clockwise around an area of high pressure and counter-clockwise around low pressure.

Question 3

What is atmosphere? Write about its different layers.

Accepted Answer

An atmosphere is a layer or a set of layers of gases surrounding a planet. An atmosphere is more likely to be retained if the gravity it is subject to is high and the temperature of the atmosphere is low. The atmosphere can be divided into layers based on its temperature. These layers are the troposphere, the stratosphere, the mesosphere and the thermosphere. A further region, beginning about 500 km above the Earth's surface, is called the exosphere.

Question 4

Short Answer Type Question.Give an account of atmosphere.

Accepted Answer

Atmosphere is the thin layer of air that surrounds the earth. It is made up of various gases such as oxygen, nitrogen, carbon dioxides, dust particles and water vapour. The gravitational force of the earth holds the atmosphere around it. It protects us from harmful rays and scorching heat of the sun. The changes in atmosphere produce changes in the weather and climate.

Question 5

The horizontal movement of air is called ________.

Accepted Answer

Wind is defined as the perceptible natural movement of the air, especially in the form of a current of air blowing from a particular direction whereas breeze is the gentle wind.

Question 6

Long AnswerGive an account of the different layers of the atmosphere.

Accepted Answer

Our atmosphere has five different layers. They are:1. Troposphere: This is the most important layer of the atmosphere with an average height of 13 km from the earth. It is in this layer that we find the air that we breathe. Almost all the weather phenomena such as rainfall, fog and hailstorm occur here.2. Stratosphere: This layer extends up to a height of 50 km. It presents the most ideal condition for flying airplanes. It contains a layer of ozone gas which protects us from the harmful effect of the sun rays.3. Mesosphere: This layer extends up to a height of 80 km. Meteorites bum up in this layer on entering from the space.4. Thermosphere: In this layer, the temperature rises very rapidly with increasing height. The ionosphere is a part of this layer. It extends between 80-400 km. This layer helps in radio transmission. Radio waves transmitted from the earth the reflected back to the earth by this layer.5. Exosphere: It is the uppermost layer where there is very thin air. Light gases such as helium and hydrogen float into space from here.

Question 7

The atmospheric layer nearest to the earth's surface is called _______________.

Accepted Answer

Earth's atmosphere consists a series of layers having their own specific traits. There layers are arranged in ascending order from the Earth's surface. As follows :-1] Troposphere2]Stratosphere3]MesosphereTroposphere is nearest to the ground level. We humans live in Troposphere .It covers the area 10 km above the surface of earth.The correct answer is A .

Question 8

Which one of the following is generally not considered a major element of weather and climate?

Accepted Answer

The
state of atmosphere over an area at any point of time is known as weather. It
is the state of the atmosphere over short periods of time. Weather can change
from hour to hour, day to day, month to month or even year to year. Weather
pattern recorded for more than 30 years of a region is considered its climate.Following are the major elements of weather and climate:-PrecipitationHumidityAir temperatureAir pressureWind speed

Question 9

Which of the following layers of the atmosphere is free from clouds?

Accepted Answer

The
stratosphere is a layer of earth’s atmosphere. It is the second layer of atmosphere
as we move upward. The stratosphere is
very dry because air in this layer contains little water vapour. Because of
this, stratosphere is free from clouds. Almost all clouds occur in the lower layer
i.e. more humid troposphere.

Question 10

Answer the following questions briefly.Name the different layers of atmosphere.

Accepted Answer

The atmosphere is comprised of layers based on temperature. These layers are the troposphere, stratosphere, mesosphere and thermosphere. A further region at about 500 km above the Earth's surface is called the exosphere.