Rajasthan Board RBSE Class 11 Physical Geography Chapter 11 Atmosphere: Composition and Structure
RBSE Class 11 Physical Geography Chapter 11 Text Book Questions
RBSE Class 11 Physical Geography Chapter 11 Multiple Choice Questions
Question 1.
The highest amount of gas in the atmosphere is:
(a) Carbon dioxide
(b) Nitrogen
(c) Oxygen
(d) Argon
Answer:
(b) Nitrogen
Question 2.
In which layer of the atmosphere weather phenomena take place?
(a) Stratosphere
(b) Troposphere
(c) Ionosphere
(d) Mesosphere
Answer:
(b) Troposphere
Question 3.
Layer of tile atmosphere called ‘Roof of weather changes:
(a) Troposphere
(b) Ionosphere
(c) Stratosphere
(d) Mesosphere
Answer:
(a) Troposphere
Question 4.
What is the average amount of water vapor present in the atmosphere?
(a) 1%
(b) 2%
(c) 3%
(d) 4%
Answer:
(b) 2%
Question 5.
The most extensive layer of the atmosphere is:
(a) Stratosphere
(b) Troposphere
(c) Ionosphere
(d) Exosphere
Answer:
(d) Exosphere
RBSE Class 11 Physical Geography Chapter 11 Very Short Answer Type Questions
Question 1.
How many types of gases are found in the atmosphere?
Answer:
In the atmosphere, there are mainly 9 types of gases.
Question 2.
What is meant by Dust particles?
Answer:
Micro particles suspended in the atmosphere due to the movement of the air. These particles are often those of fine soil, dust, sea salt, volcanic ash, meteorites. These are jointly called dust particles.
Question 3.
What is the stratosphere?
Answer:
The stratosphere is a layer situated between the troposphere and the Mesosphere in the structure of the atmosphere. Due to the temperature being constant here, this layer is called the stratosphere.
Question 4.
Where is the ozone layer found?
Answer:
The ozone layer is found in the lower part of the stratosphere. It is generally considered to be present between 18 – 38 km.
Question 5.
In which layer there is abundance of helium gas?
Answer:
The abundance of helium gas is found in the upper layer of the atmosphere, in the exosphere.
RBSE Class 11 Physical Geography Chapter 11 Short Answer Type Questions
Question 1.
What is meant by atmosphere?
Answer:
The earth is surrounded by an envelope of gases from all around. This gaseous envelope of the Earth is called the atmosphere. The altitude of the atmosphere is thousands of kilometer. The atmosphere cannot be separated from the earth like the lithosphere and the hydrosphere. Many gases are present in the atmosphere. No person or organism can live without air. Air is the basis of life of all the living beings in the world.
Question 2.
Which are the major gases found in the atmosphere?
Answer:
The most prominent gas found in the atmosphere is nitrogen. The proportion of this gas is approximately 78.08 per cent. Apart from this, other gases include oxygen 20.95 per cent, argon 0.93 per cent, carbon dioxide 0.03 per cent, neon 0.0018 per cent, helium 0.0005 per cent, ozone 0.00006 per cent and hydrogen 0.00005 per cent.
Question 3.
What is the significance of water vapor and dust particles in the atmosphere?
Answer:
Water vapor and dust particles are highly important in the atmosphere. Their importance has been described as follows:
1. The importance of water vapor:
- Water vapor absorbs some part of the Sun rays coming from the sun.
- It stores the heat radiated out by the earth.
- Water Vapor acts like a blanket for the earth, causing the earth to be neither too hot nor too cold.
- Condensation of water vapor results in precipitation.
2. The importance of Dust particles:
- Due to dust particles, the sky appears blue in colour.
- At sunrise and sunset, the colour of the sky appears to be red due to dust particles.
- Dust particles work as a nucleus in the formation of fog, mist and haze. Water vapor is found around them.
Question 4.
What are the characteristics of the troposphere?
Answer:
The following are the characteristics of the troposphere:
- This is the lowest layer of the atmosphere.
- In this sphere, 75 per cent of the total weight of the atmosphere is centered.
- Its height is less on the poles and more on the equator.
- All weather phenomena occur only in this sphere.
- On moving higher through this sphere, the temperature decreases by 6.4°C per 1000 m.
- In this layer of the atmosphere, the maximum amount of water vapor and dust is found.
- Convectional activity takes place in this sphere.
- In this sphere, the phenomenon of cloud formation and rainfall is found.
Question 5.
Describe the significance of the atmosphere and its layers.
Answer:
Importance of the atmosphere:
- Many useful gases are found in the atmosphere.
- From the atmosphere, we get protection against harmful effects of ultraviolet rays.
- Temperature and humidity found in the atmosphere influence human life.
- Due to the atmosphere, various natural landscapes are present in front of us.
Layers of the atmosphere:
The atmosphere is divided mainly into the following five layers:
1. Troposphere:
This lower layer extends from the ground up to 8 km. on the poles and 18 km. on the equator.
2. Stratosphere:
This layer of the atmosphere extends from the ground up to 50 km. (above the troposphere).
3. Mesosphere:
Between 50 to 80 km. from the earth’s above the stratosphere.
4. Ino – sphere:
This layer extends from 80 km. to 400 km, from the ground level.
5. Exosphere:
This layer is considered to be extending from 400 km. from the ground to an infinite extent.
RBSE Class 11 Physical Geography Chapter 11 Essay Type Questions
Question 1.
Explain the composition of the atmosphere.
Answer:
The gaseous cover found around the Earth is called the atmosphere.
Composition of the atmosphere:
The atmosphere is a mixture of many gases. Apart from these gases, water vapour and dust is also found in the atmosphere. There are mainly 9 kinds of gases found in the atmosphere, in which nitrogen, oxygen, argon, carbon dioxide, helium, neon, hydrogen, krypton and ozone are the major ones.
All of these gases, the highest amount of nitrogen gas (78.08 per cent) is found in the atmosphere. After this, oxygen comes at 20.95 per cent, argon at 0.93 per cent, carbon dioxide at 0. 03 per cent, neon at 0.0018 per cent, helium at 0.0005 per cent, ozone at 0.000006 per cent and hydrogen at 0.00005 per cent.
The details of some major gases found in the atmosphere are as follows:
1. Nitrogen:
This gas reflects the effect of air pressure, wind speed and reflection of light. It does not have any colour, odor or taste. This gas produces proteins in trees-plants. It is a helpful gas in the control of fire.
2. Oxygen:
It is a life supporting gas. It is an essential gas for the burning of objects that provides energy and also creates carbohydrates.
3. Ozone:
This is a very important gas which absorbs the harmful ultraviolet rays of the sun. It is important for solar radiation and climate.
4. Carbon dioxide:
This gas arising from the burning of objects is helpful in photosynthesis. Presently, its volume is increasing.
Water vapor:
Water vapor is present in the lower layers of the atmosphere. 90 per cent of the entire water vapor in the atmosphere extends up to 8 km. .The average amount of water vapor in the atmosphere is 2 per cent.
Dust particles:
Particles of microscopic dust suspended due to the motion of air in the atmosphere. These dust particles come in the form of fine soil, dust, sea salt, volcanic ash and meteorite dust. The presence of these dust particles is found only in the lower layers of the atmosphere.
Question 2.
Describe the layers of the atmosphere.
Answer:
The atmosphere is divided into many concentric layers. The layers present at different heights from the surface are divided into mainly the following five layers. The basis of this division of layers is considered to be the vertical distribution of temperature in the atmosphere:
1. Troposphere:
This is the lowest layer of the atmosphere, in which 75 per cent of the total weight of the atmosphere is centered. The average height of this layer is 13 kms. Its height is 18 km. on the equator and 8 and 10 km on the poles.
This is the most important layer of the atmosphere because all weather phenomena occur in this layer. The decline in temperature with the increase in height is the biggest feature of this layer. In this, through a height of 1 km, the temperature decreases to 6.4 Celsius, which is called ‘normal lapse rate’ of temperature.
Almost all the processes related to seasons and weather that affect human beings are carried out in this layer. In this layer, dust particles and water vapor are present in large amount, causing formation of clouds, rainfall, and other climatic and weather related events. This layer is a subject of extensive study for the scientists.
The upper layer of the troposphere is called the Tropopause. Its thickness is only 1.5 km. Above this layer there is atmospheric stability. It is also called ‘the roof of seasonal changes’. This layer stops the fall of the temperature of the atmosphere.
2. Stratosphere:
Its average height is considered to be 50 kilometers from the surface. Its thickness is less on the equator and more on the poles. Many scientists have considered ozone layer as part of the stratosphere due to which the height of this layer is considered to be 50 to 55 km. This layer is called stratosphere because the temperature remains constant here. Ozone layer is present in this layer, which absorbs ultraviolet rays coming from the Sun.
3. Mesosphere:
It is extended up to 80 km. above the stratosphere. In this layer, the temperature starts falling along with altitude and the minimum temperature remains at -80°C. Further, the temperature increases.
4. Ionosphere:
This layer starts from the upper boundary of the mesosphere. This layer extends up to 80-400 km. Electrical and magnetic phenomena occur in this layer. Radio waves return by reflecting from this layer. This sphere is divided into D, E and F layers. In this layer, the aurora borealis and the aurora australis occur. This sphere is the lowest part of the thermosphere.
5. Exosphere:
This is the topmost part of the atmosphere which spreads above 400 km. There is no upper boundary layer of this layer. It is also called Magnetosphere, In this layer of the atmosphere, the gases become very sparse. In this layer, heat becomes excessive. Due to this, more information about this layer has not been obtained yet.
All these layers of the atmosphere are represented through the further diagram:
Question 3.
“Atmosphere is the basis of life on the earth.” Perform a scientific analysis of this statement.
Answer:
The atmosphere is the basis of life on Earth because life is possible on earth due to atmospheric conditions. Due to these atmospheric conditions, the earth is considered to be a unique planet as compared to other planets. The atmospheric significance found in the context of the Earth and for the existence of life is explained by the following points:
- The existence of a variety of organisms on the surface of the Earth has only been possible due to the atmosphere.
- There are many useful gases present in the atmosphere.
- Gases of the atmosphere are used to make possible various human activities.
- A component of the atmosphere, the water vapor, plays an important role in determining the climate.
- Various types of weather phenomena, such as condensation, precipitation, cloud formation, rainfall, frost, snow, dew, hailstone, etc. are the result of atmospheric conditions.
- Organic dust particles of the atmosphere are most important because they cause many events.
- The colour of the sky as blue, the appearance of the sky as red in colour during sunrise and sunset, the scattering of the sun’s rays and the reflection of the atmosphere is due to the presence of dust particles.
- Salt and smoke particles attract water vapor, due to which, the process of condensation takes place.
- The events visible in the form of fog, mist and haze are also the result of the water vapor and dust particle presence of the atmosphere.
- The atmosphere protects us by absorbing the ultraviolet rays coming from the sun.
- Replacement of radio waves is possible due to the layer of ionic particles found in the atmosphere.
All the points mentioned above are the evidence of the fact that the atmosphere and its various layers prove to be the basis of the biological world. If the atmospheric conditions on earth did not exist, then the Earth would also be a deserted planet, just like other planets. From the human perspective, its highest importance is because the direct and indirect influence of atmospheric conditions is the greatest controller of all human activities.
RBSE Class 11 Physical Geography Chapter 11 Other Important Questions
RBSE Class 11 Physical Geography Chapter 11 Multiple Choice Questions
Question 1.
Which layer causes absorption of ultraviolet rays coming from the Sun?
(a) Troposphere
(b) Ozone layer
(c) Mesosphere
(d) Ionosphere
Answer:
(b) Ozone layer
Question 2.
How much volume of atmosphere is comprised by nitrogen and oxygen gas?
(a) About 69 %
(b) About 79 %
(c) Approximately 89%
(d) About 99 %
Answer:
(d) About 99 %
Question 3.
The most important gas for humans:
(a) Nitrogen
(b) Oxygen
(c) Argon
(d) Helium
Answer:
(b) Oxygen
Question 4.
Helping gas in the control of fire:
(a) Oxygen
(b) Nitrogen
(c) Hydrogen
(d) Helium
Answer:
(b) Nitrogen
Question 5.
Which gas is used by the plants in the process of photosynthesis?
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide
(d) Argon
Answer:
(c) Carbon dioxide
Question 6.
The amount of which gas is growing continuously?
(a) Argon
(b) Neon
(c) Krypton
(d) Carbon dioxide
Answer:
(d) Carbon dioxide
Question 7.
What is called the blanket of the earth?
(a) Nitrogen
(b) Water vapor
(c) Dust particles
(d) Hydrogen
Answer:
(b) Water vapor
Question 8.
Which is not included in the atmospheric conditions?
(a) Temperature
(b) Air pressure
(c) Rainfall
(d) Height
Answer:
(d) Height
Matching Type Questions
Question 1.
Match column A with column B in the following:
| Column A (Atmospheric gas) | Column B (Percentage in the atmosphere) |
| (i) Nitrogen | (a) 0.93% |
| (ii) Oxygen | (b) 0.03% |
| (iii) Argon | (c) 20.95% |
| (iv) Carbon dioxide | (d) 0.0018% |
| (v) Neon | (e) 78.08% |
Answers:
- (e)
- (c)
- (a)
- (b)
- (d)
Question 2.
Match column A with column B in the following:
| Column A (Name of the layer) | Column B (Upper boundary of layer) |
| (i) Troposphere | (a) 400 km |
| (ii) Stratosphere | (b) no boundary |
| (iii) Mesosphere | (c) 50 km |
| (iv) Ionosphere | (d) 80 km |
| (v) Exosphere | (e) 8 – 18 km |
Answers:
- (e)
- (c)
- (d)
- (a)
- (b)
RBSE Class 11 Physical Geography Chapter 11 Very Short Answer Type Questions
Question 1.
What is the definition of the atmosphere as given by Finch and Trewartha?
Answer:
According to Finch and Trewartha, “The atmosphere is a cover of gases that extends from the ground up to a height of hundreds of miles and is an integral part of the Earth”.
Question 2.
What is the definition of atmosphere according to the Monk – house?
Answer:
According to Monk – house , “The atmosphere is a thin layer of gas which is associated with the earth due to gravity.”
Question 3.
What is the significance of ozone layer?
Answer:
This layer of the atmosphere protects us by absorbing harmful ultraviolet rays coming from the sun.
Question 4.
What affects human life?
Answer:
Human life is influenced by the conditions of temperature, humidity, and air circulation in the atmosphere.
Question 5.
What are the highest and lowest amount of gases in the atmosphere?
Answer:
Nitrogen is found in the highest amount in the atmosphere (78.8%) and the lowest proportion is of hydrogen (0.00005%).
Question 6.
What is the effect of nitrogen gas?
Answer:
Nitrogen gas impacts the air pressure, wind power and reflection of light.
Question 7.
What does the term photosynthesis mean?
Answer:
The process by which plants make food in the presence of sunlight using carbon dioxide gas and water, is called photosynthesis.
Question 8.
What is the meaning of global warming?
Answer:
Due to the worsening conditions of environmental pollution and pollution of the entire world, the earth’s temperature is on a continuous rise. This is called global warming.
Question 9.
Water vapor is like a blanket for the earth, how?
Answer:
Water vapor absorbs some part of sunlight coming from the sun and stores the heat radiated out by the earth. In this way, it acts like a blanket.
Question 10.
Where is dust particles mainly produced from?
Answer:
Dust is mainly produced from erosion of rocks, oceanic salt, volcanic ash, meteorite implosions and soil.
Question 11.
Why does the sky appear blue?
Answer:
Due to the scattering of sunlight by atmospheric gases and dust particles, the colour of the sky appears to be blue.
Question 12.
Where do you find more dust particles?
Answer:
Relatively more dust particles are found in the industrial cities and the dry air of arid territories.
Question 13.
Which layers are included in the atmosphere?
Answer:
In the atmosphere, there are five layers, known as the troposphere, the stratosphere, the mesosphere, the ionosphere and the exosphere.
Question 14.
How much is the width/thickness of the troposphere?
Answer:
The thickness of the troposphere is 8 – 10 km. on the poles and 18 km. on the equator.
Question 15.
What is the condensation?
Answer:
The process through which a substance changes from vapor to liquid state; As: Clouds formed from condensation of water vapor in the atmosphere.
Question 16.
Where do weather phenomena occur?
Answer:
All weather phenomena occur in the lowest layer of the atmosphere, in the troposphere.
Question 17.
Where is the mesosphere spreaded?
Answer:
The mesosphere, layer above the stratosphere, is extended from 50 km. to the lowest extent of the ionosphere, i.e.80 km.
Question 18.
What is Mesopause?
Answer:
At the upper boundary of the mesosphere, i.e. at 80 km. the temperature decreases to -80°C. This state is called Mesopause of mesosphere.
Question 19.
How is the ionosphere beneficial?
Answer:
The ionosphere is a layer that reflects the radio waves which are highly beneficial for us. Also the origin of Aurora is possible due to this layer.
Question 20.
What is the extension of the ionosphere?
Answer:
The ionosphere extends from the upper boundary of the mesosphere, i.e., 80 km. to the lowest boundary of the exosphere, i.e., 400 km.
Question 21.
What is called as the exosphere?
Answer:
The topmost layer of the atmosphere which extends over 400 km. and which has no upper boundary is called exosphere or magnetosphere.
Question 22.
What is meant by weather?
Answer:
The weather refers to the sum total of atmospheric conditions prevailing at a particular time at a particular location.
RBSE Class 11 Physical Geography Chapter 11 Short Answer Type Questions (SA-I)
Question 1.
Explain the importance of the atmosphere.
Or
Explain the utility of the atmosphere.
Answer:
Many useful gases are found in the atmosphere, such as oxygen, nitrogen, carbon dioxide, hydrogen, etc. The cover of the atmosphere protects us from harmful effects of ultraviolet rays coming from the sun. Human life is influenced by the temperature and humidity contained in the atmosphere. The atmosphere produces a variety of natural landscapes for us and its composition has the power to keep us alive. If the atmosphere was not there, any kind of life would not be possible on the ground, and this earth be would a deserted, lifeless place just like other planets.
Question 2.
Explain the composition of the atmosphere.
Answer:
The atmosphere is a mixture of many gases. In addition to these gases, water vapor and dust particals is found in the atmosphere. In the atmosphere, mainly nitrogen, oxygen, argon, carbon dioxide, hydrogen, helium, neon, krypton, and ozone gases are found. Water vapor is centered in the lower layers of the atmosphere. The average proportion of water vapor in the atmosphere is about 2 per cent. Apart from these, dust particles are also found in the atmosphere in the form of particles of sea salt, volcanic ash, dust and meteorite waste.
Question 3.
Explain the importance of oxygen gas.
Answer:
The significance of oxygen gas is shown in the following points:
- It is a life – supporting gas.
- This gas combined with other chemical elements, easily forms many compounds.
- This is necessary for the burning of various items.
- This gas is the main source of energy.
- This gas has an important role in carbohydrate production.
Question 4.
Why is the thickness of the troposphere highest at the equator?
Answer:
There is a variation in the elevation of the troposphere. It is 8 km. on the poles and up to 18 km. at the equator. On the equatorial line, more insolation is obtained due to the direct sun rays of the sun, resulting in convectional currents. These streams transmit heat to high altitudes. Due to this, the thickness of the troposphere is more at the equator.
Question 5.
Explain tlie four characteristics of the stratosphere.
Answer:
The characteristics of the stratosphere are as following:
- The temperature remains the same in this sphere.
- This is the most useful sphere for flying aircraft.
- This layer of the atmosphere is found to be less thick on the equator and more thick on the poles.
- The ozonosphere is found in this layer of atmosphere which protects us from the ultraviolet rays received from the sun.
Question 6.
Explain the importance of ozone gas.
Answer:
Ozone gas is found in the lower boundary of the stratosphere between 15 and 35 km. It works like a protective cover. It absorbs the ultraviolet rays coming from the Sun, so that the temperature of the earth’s surface remains normal. If these rays came straight to the ground, then the temperature would have increased so much that the existence of organisms on the ground could not have been possible.
At present, due to the innovative technology and technological developments, the layer of ozone gas is depleting, due to which, the temperature on the earth is increasing continuously. Thus mankind is causing problems for it self.
Question 7.
Summarize the importance of the ionosphere.
Answer:
The ionosphere is spread from 80 to 400 km. above the mesosphere. In this, electrically-charged particles are found which are called ions. On this basis, it is called the ionosphere. In this sphere, the presence of cosmic rays is there. The three layers are found in the ionosphere : the long and medium radio waves named D, E and F, and from these, E and F levels are reflected on the surface. If they were not there, then these waves would go into the infinite universe. In the ionosphere, there is the view of Aurora Borealis and Aurora Australis.
RBSE Class 11 Physical Geography Chapter 11 Short Answer Type Questions (SA-II)
Question 1.
Explain the importance of nitrogen gas.
Or
Prove the usefulness of nitrogen gas.
Answer:
Nitrogen is an important gas of the atmosphere. Its importance is clarified in the following points:
- The presence of this gas makes us experience the effect of the heat, the motion of the wind and the reflection of light.
- It is a colorless, odorless and tasteless gas.
- This gas prevents the things from burning rapidly.
- Protein is produced in plants due to this gas.
- If there was no nitrogen gas in the atmosphere then it would be difficult to control the fire.
- The nitrogen cycle is completed due to this gas.
Question 2.
Describe the characteristic of carbon dioxide gas.
Answer:
The following are the characteristics of carbon dioxide gas:
- It is a heavy gas.
- Carbon dioxide is evolved due to burning the fuel and organic matter.
- Due to this gas, the process of photosynthesis takes place in plants.
- It is a gas whose volume is not constant in the atmosphere.
- The volume of this gas is increasing.
- Increased volume of this gas is causing problems like global warming and climate change.
Question 3.
Describe the troposphere.
Answer:
Troposphere is the lowest layer of the atmosphere in which 75 per cent of the total weight of the atmosphere is centered. The average height of this layer is 13 km. Its height is 18 km on the equator and 8 – 10 km. on the poles. This is the most important layer of the atmosphere. Because all weather phenomena in this sphere.
In this layer, the temperature decreases along with the increase in height from the surface. This decrease in temperature is at the rate of 6.4°C per 1000 meters. This fall in temperature with height is known as normal lapse rate. This layer contains plenty of dust particles and water vapor. Clouds are formed due to this.
Rainfall and other climate and weather related events occur due to this. This layer is a subject of deep study of meteorologists. The upper boundary of this sphere is called the tropopause. Its thickness is only 1.5 km. Above this boundary, there is atmospheric stability. It is also called the roof of seasonal changes.
Question 4.
Explain the elements of weather and climate.
Or
Explain weather and climate and its constituent elements.
Answer:
The sum total of the atmospheric conditions at a particular time on a particular place is called ‘weather’. Therefore, the weather depicts the specific conditions of the atmosphere. In atmospheric conditions, factors like temperature, air pressure, rainfall, winds, humidity etc. are included. These components are called the elements of the weather. The weather conditions often change.
As a result, ‘elements of weather’ also change. Therefore, the weather for a particular place also varies. This change is due to the difference in the volume, activation and distribution of the elements of the weather from day to day or from one place to another. Factors controlling this change of the elements of the weather are called ‘Weather Controllers’.
Under this, uneven distribution of latitude, water and space, sea currents, air pressure, height from sea level, mountain blockade, nature of the surface, etc. are included.