Class 11 Geography: Composition and Structure of Atmosphere — Chapter Question Set

(b) Nitrogen — This is the textbook-supported choice for the question.

(c) Troposphere — This is the textbook-supported choice for the question.

(b) Dust particles — This is the textbook-supported choice for the question.

(b) 120 km — This is the textbook-supported choice for the question.

(d) Carbon dioxide — This is the textbook-supported choice for the question.

d) breathe every few seconds — The textbook states: We eat food two - three times a day and drink water more frequently but breathe every few seconds.

c) minutes without breathing air — The textbook states: Some organisms like humans may survive for some time without food and water but can’t survive even a few minutes without breathing air.

b) atmosphere in greater detail — The textbook states: That shows the reason why we should understand the atmosphere in greater detail.

a) a mixture of different gases and it envelopes — The textbook states: Atmosphere is a mixture of different gases and it envelopes the earth all round.

d) carbon dioxide for plants — The textbook states: It contains life-giving gases like oxygen for humans and animals and carbon dioxide for plants.

c) 99 per cent — The textbook states: The air is an integral part of the earth’s mass and 99 per cent of the total mass of the atmosphere is confined to the height of 32 km from the earth’s surface.

b) colourless and odourless and can be felt only — The textbook states: The air is colourless and odourless and can be felt only when it blows as wind.

a) ozone in the atmosphere? — The textbook states: Can you imagine what will happen to us in the absence of ozone in the atmosphere?

d) composed of gases — The textbook states: COMPOSITION OF THE ATMOSPHERE The atmosphere is composed of gases, water vapour and dust particles.

c) 120 km — The textbook states: The proportion of gases changes in the higher layers of the atmosphere in such a way that oxygen will be almost in negligible quantity at the height of 120 km.

b) 90 km — The textbook states: Similarly, carbon dioxide and water vapour are found only up to 90 km from the surface of the earth.

a) meteorologically a very important gas as it i — The textbook states: Gases Carbon dioxide is meteorologically a very important gas as it is transparent to the incoming solar radiation but opaque to the outgoing terrestrial radiation.

d) towards the earth’s surface — The textbook states: It absorbs a part of terrestrial radiation and reflects back some part of it towards the earth’s surface.

c) constant but the volume of carbon dioxide has — The textbook states: The volume of other gases is constant but the volume of carbon dioxide has been rising in the past few decades mainly because of the burning of fossil fuels.

b) temperature of the air — The textbook states: This has also increased the temperature of the air.

a) 50 km — The textbook states: Ozone is another important component of the atmosphere found between 10 and 50 km above the earth’s surface and acts as a filter and absorbs the ultra-violet rays radiating from the sun and prevents them from reaching the surface of the earth.

d) also a variable gas in the atmosphere — The textbook states: Water Vapour Water vapour is also a variable gas in the atmosphere, which decreases with altitude.

c) of the air — The textbook states: In the warm and wet tropics, it may account for four per cent of the air by volume, while in the dry and cold areas of desert and polar regions, it may be less than one per cent of the air .

b) equator towards the poles — The textbook states: Water vapour also decreases from the equator towards the poles.

a) the earth’s radiated heat — The textbook states: It also absorbs parts of the insolation from the sun and preserves the earth’s radiated heat.

d) cold nor too hot — The textbook states: It thus, acts like a blanket allowing the earth neither to become too cold nor too hot.

c) instability in the air — The textbook states: Water vapour also contributes to the stability and instability in the air.

b) OF ATMOSPHERE — The textbook states: CHAPTER COMPOSITION AND STRUCTURE OF ATMOSPHERE 65 Dust Particles Atmosphere has a sufficient capacity to keep small solid particles, which may originate from different sources and include sea salts, fine soil, smoke-soot, ash, pollen, dust and disintegrated particles of meteors.

a) generally concentrated in the lower layers of — The textbook states: Dust particles are generally concentrated in the lower layers of the atmosphe re; yet, convectional air currents may transport them to great heights.

d) found in subtropical and temperate regions d — The textbook states: The higher concentration of dust particles is found in subtropical and temperate regions d ue to dry winds in comparison to equatorial and polar regions.

c) condenses to produce clouds — The textbook states: Dust and salt particles act as hygroscopic nuclei around which water vapour condenses to produce clouds.

b) dif ferent layers with varying density and te — The textbook states: STRUCTURE OF THE ATMOSPHERE The atmosphere consists of dif ferent layers with varying density and temperature.

a) highest near the surface of the earth and dec — The textbook states: Density is highest near the surface of the earth and decreases with increasing altitude.

d) divided into five dif fer ent layers dependin — The textbook states: The column of atmosphere is divided into five dif fer ent layers depending upon the temperature condition.

c) mesosphere, thermosphere and exosphere — The textbook states: They are: troposphere, stratosphere, mesosphere, thermosphere and exosphere.

b) 13 km — The textbook states: Its average height is 13 km and extends roughly to a height of 8 km near the poles and about 18 km at the equator .

a) greatest at the equator because heat is trans — The textbook states: Thickness of the troposphere is greatest at the equator because heat is transported to great heights by strong convectional currents.

d) particles and water vapour — The textbook states: This layer contains dust particles and water vapour.

c) in this layer — The textbook states: All changes in climate and weather take place in this layer .

b) 1°C — The textbook states: The temperature in this layer decreases at the rate of 1°C for every 165m of height.

a) known as the tropopause — The textbook states: The zone separating the tropsophere from stratosphere is known as the tropopause.

d) 45oC — The textbook states: The air temperature at the tropopause is about minus 800C over the equator and about minus 45oC over the poles.

c) nearly constant — The textbook states: The temperature here is nearly constant, and hence, it is called the tropopause.

b) 50 km — The textbook states: The stratosphere is found above the tropopause and extends up to a height of 50 km.

a) that it contains the ozone layer — The textbook states: One important feature of the stratosphere is that it contains the ozone layer.

d) harmful form of energy — The textbook states: This layer absorbs ultra-violet radiation and shields life on the earth from intense, harmful form of energy.

c) 80 km — The textbook states: The mesosphere lies above the stratosphere, which extends up to a height of 80 km.

b) 100°C — The textbook states: In this layer, once again, temperature starts decreasing with the increase in altitude and reaches up to minus 100°C at the height of 80 km.

a) known as the mesopause — The textbook states: The upper limit of mesosphere is known as the mesopause.

d) 400 km — The textbook states: The ionosphere is located between 80 and 400 km above the mesopause.

That shows the reason why we should understand the atmosphere in greater detail. Atmosphere is a mixture of different gases and it envelopes the earth all round. Can you imagine what will happen to us in the absence of ozone in the atmosphere?

All changes in climate and weather take place in this layer .

That shows the reason why we should understand the atmosphere in greater detail. COMPOSITION OF THE ATMOSPHERE The atmosphere is composed of gases, water vapour and dust particles. CHAPTER COMPOSITION AND STRUCTURE OF ATMOSPHERE 65 Dust Particles Atmosphere has a sufficient capacity to keep small solid particles, which may originate from different sources and include sea salts, fine soil, smoke-soot, ash, pollen, dust and disintegrated particles of meteors.

Atmosphere is a mixture of different gases and it envelopes the earth all round. This is the most important layer for all biological activity. Although all layers of the atmosphere must be exercising influence on us, geographers are concerned with the first two layers of the atmosphere.

We eat food two - three times a day and drink water more frequently but breathe every few seconds.

Air is essential to the survival of all organisms.

Some organisms like humans may survive for some time without food and water but can’t survive even a few minutes without breathing air.

That shows the reason why we should understand the atmosphere in greater detail.

Atmosphere is a mixture of different gases and it envelopes the earth all round.

It contains life-giving gases like oxygen for humans and animals and carbon dioxide for plants.

The air is an integral part of the earth’s mass and 99 per cent of the total mass of the atmosphere is confined to the height of 32 km from the earth’s surface.

The air is colourless and odourless and can be felt only when it blows as wind.

Can you imagine what will happen to us in the absence of ozone in the atmosphere?

COMPOSITION OF THE ATMOSPHERE The atmosphere is composed of gases, water vapour and dust particles.

The proportion of gases changes in the higher layers of the atmosphere in such a way that oxygen will be almost in negligible quantity at the height of 120 km.

Similarly, carbon dioxide and water vapour are found only up to 90 km from the surface of the earth.

Gases Carbon dioxide is meteorologically a very important gas as it is transparent to the incoming solar radiation but opaque to the outgoing terrestrial radiation.

It absorbs a part of terrestrial radiation and reflects back some part of it towards the earth’s surface.

It is largely responsible for the green house effect.

The volume of other gases is constant but the volume of carbon dioxide has been rising in the past few decades mainly because of the burning of fossil fuels.

This has also increased the temperature of the air.

Ozone is another important component of the atmosphere found between 10 and 50 km above the earth’s surface and acts as a filter and absorbs the ultra-violet rays radiating from the sun and prevents them from reaching the surface of the earth.

Water Vapour Water vapour is also a variable gas in the atmosphere, which decreases with altitude.

In the warm and wet tropics, it may account for four per cent of the air by volume, while in the dry and cold areas of desert and polar regions, it may be less than one per cent of the air .

Water vapour also decreases from the equator towards the poles.

That shows the reason why we should understand the atmosphere in greater detail. Atmosphere is a mixture of different gases and it envelopes the earth all round. The air is an integral part of the earth’s mass and 99 per cent of the total mass of the atmosphere is confined to the height of 32 km from the earth’s surface. Can you imagine what will happen to us in the absence of ozone in the atmosphere? COMPOSITION OF THE ATMOSPHERE The atmosphere is composed of gases, water vapour and dust particles. The proportion of gases changes in the higher layers of the atmosphere in such a way that oxygen will be almost in negligible quantity at the height of 120 km. CHAPTER COMPOSITION AND STRUCTURE OF ATMOSPHERE 65 Dust Particles Atmosphere has a sufficient capacity to keep small solid particles, which may originate from different sources and include sea salts, fine soil, smoke-soot, ash, pollen, dust and disintegrated particles of meteors.

That shows the reason why we should understand the atmosphere in greater detail. Atmosphere is a mixture of different gases and it envelopes the earth all round. The air is an integral part of the earth’s mass and 99 per cent of the total mass of the atmosphere is confined to the height of 32 km from the earth’s surface. Ozone is another important component of the atmosphere found between 10 and 50 km above the earth’s surface and acts as a filter and absorbs the ultra-violet rays radiating from the sun and prevents them from reaching the surface of the earth. CHAPTER COMPOSITION AND STRUCTURE OF ATMOSPHERE 65 Dust Particles Atmosphere has a sufficient capacity to keep small solid particles, which may originate from different sources and include sea salts, fine soil, smoke-soot, ash, pollen, dust and disintegrated particles of meteors. STRUCTURE OF THE ATMOSPHERE The atmosphere consists of dif ferent layers with varying density and temperature. The column of atmosphere is divided into five dif fer ent layers depending upon the temperature condition.

We eat food two - three times a day and drink water more frequently but breathe every few seconds. We eat food two - three times a day and drink water more frequently but breathe every few seconds. Air is essential to the survival of all organisms. Some organisms like humans may survive for some time without food and water but can’t survive even a few minutes without breathing air.

Air is essential to the survival of all organisms. We eat food two - three times a day and drink water more frequently but breathe every few seconds. Air is essential to the survival of all organisms. Some organisms like humans may survive for some time without food and water but can’t survive even a few minutes without breathing air. That shows the reason why we should understand the atmosphere in greater detail.

Some organisms like humans may survive for some time without food and water but can’t survive even a few minutes without breathing air. Air is essential to the survival of all organisms. Some organisms like humans may survive for some time without food and water but can’t survive even a few minutes without breathing air. That shows the reason why we should understand the atmosphere in greater detail. Atmosphere is a mixture of different gases and it envelopes the earth all round.

That shows the reason why we should understand the atmosphere in greater detail. Some organisms like humans may survive for some time without food and water but can’t survive even a few minutes without breathing air. That shows the reason why we should understand the atmosphere in greater detail. Atmosphere is a mixture of different gases and it envelopes the earth all round. It contains life-giving gases like oxygen for humans and animals and carbon dioxide for plants.

Atmosphere is a mixture of different gases and it envelopes the earth all round. That shows the reason why we should understand the atmosphere in greater detail. Atmosphere is a mixture of different gases and it envelopes the earth all round. It contains life-giving gases like oxygen for humans and animals and carbon dioxide for plants. The air is an integral part of the earth’s mass and 99 per cent of the total mass of the atmosphere is confined to the height of 32 km from the earth’s surface.