Rajasthan Board RBSE Class 7 Social Science Chapter 2 Atmosphere and Climate
RBSE Class 7 Social Science Atmosphere and Climate Intext Questions and Answers
Page No 12.
List the main gases and their percentage by observing the picture of atmosphere.
- Nitrogen (78.08%)
- Oxygen (20.95%)
- Argon (0.93%)
- Carbon dioxide (0.038%)
- Krypton (0.0001 %)
- Helium (0.0005%)
- Hydrogen (0.00005%)
- Neon (0.0018%)
- Geon (0.000009%).
Write a brief essay on importance of gases present in atmosphere.
- All living organism of earth depends on atmosphere for respiration which provides pure air for breathing.
- Carbon-dioxide is taken by plants to make food. This maintains balance of gases in atmosphere.
- Gases, vapor and dust particles all are present in the atmosphere. All these protect us from hot rays falling from the Sun and cold that falls at night. So it is the atmosphere which makes earth a living place for us.
Page No 13.
Name the layers of atmosphere.
Layers of Atmosphere
Fill in the following blanks.
Name of Height Main Importance layer:
- Tropo – 13 km All seasonal activities sphere occur here. Oxygen is found here. Maximum gases, vapour, dust particles are found here.
- Strato – 50 km sphere Ozone gas is found here, which protects us from ultraviolet rays from Sun by absorbing them.
- Meso – 80 km sphere The comets falling from space burn in this layer of atmosphere. Ilie radio waves from earth are
- Iono – 80 to sphere 400 km The radio waves from earth are reflected back from this layer.
- Exo – Above sphere 400 km Helium and hydrogen gases are found here.
Page No 18.
List the places in India where rainfall is above 200 cm and below 50 cm by observing distribution map of rainfall.
Places that receive more than 200 cm rainfall in India are – Assam. Meghalaya and South-West sea coastal places. Places that receive less than 50 cm rainfall in India are – Western part of Rajasthan, some part of Jammu and Kashmir and inner part of South.
RBSE Class 7 Social Science Atmosphere and Climate Text Book Questions and Answers
Choose the correct options:
1. The name of hot zone cyclone in USA is –
2. In which layer aeroplane flies?
Fill in the blanks:
- The amount of ………………….. gas is maximum in atmosphere.
- The ………………….. is the instrument for measuring velocity of wind.
- The radio waves are reflected back from ………………….. of atmosphere.
- ………………….. is the name given to air flowing in summer season in Rajasthan.
What is the difference between season and climate?
The short period of environmental conditions of particular place is called season. The average of long period seasonal conditions of a particular place is called its climate. Continuous changes in a short period take place in a season, on the other hand, changes in climate take place gradually.
How many types of rain are there? Name them.
There are three types of rainfall –
- Mountain rain
- cyclonic rain
- convectional rain.
Define wind and explain its types.
The flow of air from high pressure area to lower pressure is called wind. There are three types of winds –
1. Permanent Winds –
They are of three types – trap winds, westerly winds, and polar winds. They always flows in one direction throughout the year. Hence they are called permanent winds.
2. Seasonal Winds –
These winds change their direction in different seasons. The monsoon wind in India is an example of it. In coastal region, land breeze blows in night time and sea breeze in day time are best examples of seasonal winds.
3. Local Winds –
These winds blow in small area in a year or at a particular time in a day. In Rajasthan, the hot winds in summer called Local is an example of local winds.
Write difference between cyclone and anticyclone.
Difference between cyclone and anticyclone –
- In cyclone air pressure is low in the centre. Whereas in anticyclone air pressure is high in the centre.
- In the periphery of cyclone there is high air pressure whereas in the periphery of anticyclone there is low air pressure.
- In the cyclone the air pressure increases from centre to outside due to which air moves towards centre from periphery whereas in anticyclone there is high pressure at centre and lower towards periphery.
- Cyclones develop at sea and fall as rainfall on coastal areas whereas in the area of anticyclone weather normally remained clear and dry.
Explain organization of atmosphere.
Organization of atmosphere – Atmosphere is formed of components of gases, vapor and dust particles such as –
1. Gases –
The main gases of atmosphere’ are nitrogen, oxygen, argon, helium, neon and carbon-dioxide etc. Almost 99% atmosphere consists of nitrogen and other gases.
2. Vapor –
Besides gas, atmosphere also contains water droplets. Due to high temperature, when water changes to vapor and comes in atmosphere, then it is called water vapor. Rainfall is formed due to water vapor.
3. Dust particles –
The third important element of atmosphere is dust particles which fly here and there. The dispersion of light from their dust particles make sky appear blue to us. The redness in sky at the time of sunrise and sunset is also due to these dust particles. There are important for condensations as water vapor changes to small drops on these particles only.
Draw the diagram of layer of atmosphere and write the main significance of it.
Characteristic of atmosphere has been described with the help of diagram.
1. Troposphere –
It is the lowermost layer of atmosphere. All seasonal activities like rain, snow, storm, smog occur in this layer. The average height of this layer is 13 km. Oxygen is found here which is essential for all living organisms in respiration. Its upper limit in called Tropes limit.
2. Stratosphere –
Above Troposphere, till 50 km of height is stratosphere. Ozone gas is found here, which protect us from ultraviolet rays from Sun by absorbing them.
3. Mesosphere –
Above stratosphere till 80 km is the third layer of atmosphere called Mesosphere. The comet falling from space burn in this layer of atmosphere.
4. Ionosphere –
After mesosphere from 80 to 400 km lies fourth layer of atmosphere called ionosphere. For communication, this layer is very important. The radio waves from earth are reflected back from this layer.
5. Exosphere –
It is upper most layer of atmosphere. Hence the gases are very thin, mainly helium and hydrogen are found here.
RBSE Class 7 Social Science Atmosphere and Climate Important Questions and Answers
Objective Type Questions:
Which gas is responsible for global warming?
Air pressure will when we go higher from surface to atmosphere –
(d) None of the above
Redness is seen at the time of Sunrise and Sunset because of –
(b) dust particles
(b) dust particles
Ozone gas is found –
Hot zone cyclones in Japan are called
(d) Willy willies
The earth is surrounded with many gases from all side is called as –
Fill in the blanks:
- Due to ……………………….. of earth, atmosphere is attached to it. (gravitational force/atmosphere)
- Ozone gas protects us from ……………………….. from Sun by observing them. (ultraviolet rays/rays)
- All seasonal activities like rain, snow, storm, smog occur in ……………………….. (Troposphere/Stratosphere)
- The flow of air from high pressure area to lower pressure is called ……………………….. (wind/storm)
- The region of ……………………….. is the most rainfall fed area in the world. (equator/hot zone)
- gravitational force
- ultraviolet rays
- equator Select
True/False statement from the followings –
- Atmosphere is mixture of many gases, water-drops and dust particles.
- At present time, the percentage of carbon-dioxide in atmosphere is increasing continuously due to which temp, of earth is also increasing.
- Dust particles fly here and there in the sky. The dispersion of light from the dust particles make sky appear blue to us.
- The radio waves from earth are reflected back from Ionosphere.
- A unit of measuring temp, is called Barometer.
Match the following – Below are given layers of atmosphere, match characteristics of theirs with each other:
Layers of Atmosphere – Characteristics
- Troposphere – 13 km to 50 km upto
- Stratosphere – 80 km to 400 km upto
- Mesosphere – upto 13 km
- Ionosphere – 50 km to 400 km upto
Layers of Atmosphere – Characteristics
- Troposphere – upto 13
- Stratosphere – km 13 km to 50
- Mesosphere – km upto 50 km to 80 km
- Ionosphere – upto 80 km to 400 km
Very Short Questions:
What is the average rainfall of the world?
Name the highest rainfall receiving place/s in the world.
Cherrapunji and Mohsinraam of Meghalaya.
What is the name of instrument used for knowing direction of wind?
What is the name of instrument that measures speed of wind.
What is the name of temperature measuring instrument?
What is the name of temperature measuring unit?
Centigrade or Fahrenheit.
How is climate of sea coastal areas?
Temperature of sea coastal areas is always moderate.
What is climate?
The average of long period seasonal conditions of a particular place is called its climate.
What is atmosphere?
Atmosphere is a mixture of many gases, water drops and dust particles.
What is season?
The short period of environmental conditions of a particular place is called season.
What is air pressure?
The weight of air on the different layer of earth is called air pressure.
What is the main cause of global warming in atmosphere?
The main cause of global warming is increase in carbon-dioxide in the atmosphere.
Short Question Answers:
What is global warming?
At present time the emission from vehicles has increased the percentage of carbon dioxide in atmosphere which is responsible for increasing in temperature of earth.
What does the sky appear blue to us?
Dust particles fly here and there in the sky. The dispersion of light from the dust particles make sky appear blue to us.
Into how many layers is atmosphere divided on the basis of temperature?
Atmosphere is divided into five layers :
- Troposphere (13 km)
- Stratosphere (13 to 50 km)
- Mesosphere (50 to 80 km)
- Ionosphere (80 to 400 km)
- Exosphere (above 400 km).
What do you mean by temperature? What are the causes due to which changes occur in temperature?
The meaning of temperature is how much hot is the air. According to day-night and seasons, the temperature of air changes continuously. The temperature is maximum during the day comparing night. Similarly, in the summer it is maximum comparing winter, higher in cities than villages maximum in continents than oceans. Generally temperature decreases from equator to poles continuously as on equator the Sun rays fall directly while on poles slant.
What is air pressure? What are its characteristics?
Air Pressure – The weight of air on the different layer of earth is called air pressure. Characteristics –
- At the surface, air pressure is approx. 1 kg weight on 1 cm 2 area.
- Maximum air pressure is at sea level.
- Air pressure decreases while going upwards from sea level.
- The unit of measuring air pressure is Millibar and the instrument used for this is Barometer.
Explain in brief distribution of rain in the world.
Distribution of rain in the world –
There is no equal distribution of rainfall in the world because its distribution is influenced by many factors like direction of mountain, distance from sea, form of earth, wind etc. Region of Maximum Rainfall – The region of equator is the most rainfall shaded area in the world, where the annual rainfall is 200 cm or more.
Region of Medium rainfall – The region of medium rainfall is mainly area under hot and cold zone where the annual rainfall is of 100-200 cm. Region of Less rainfall – The area of very less rainfall are mid hot zone region, east of cold zone where average rainfall is of 25-100 cm.
What is the effect of sea and forest on climate?
The area to sea have moderate climate all the year, means there is no variation in temperature in summers and winters. There is more evaporation on the land near sea and have high rainfall. Plants also evaporate water by the process called transpiration. As a result, there is much rainfall in the forest. The areas having dense vegetation experience moderate climate.
What is cyclone? Discuss its types.
Cyclones are area of low air pressure where the high air pressure always surrounds. It means the air pressure increases from centre to outside due to which air moves towards centre from periphery.
Types of Cyclone – There are two types of Cyclone:
- Hot zone Cyclone – Hot zone cyclone moves very fast and causes great loss of life and property.
- Cold zone cyclone – Cold zone cyclone moves slowly therefore it is less disastrous.
Discuss in brief anticyclone.
Anticyclone – The circular, oval and are structure formed by air in which there is high pressure at centre and lower towards periphery is called anticyclone. The air in anticyclone blows from centre to periphery air a circular where direction is clockwise in northern hemisphere and anticlockwise in southern hemisphere. Generally, weather is clear and dry.
What is the importance of dust particles in the atmosphere.
The dispersion light from their dust particles make sky appear blue to us. The redness and formation of rainbow in sky at the time of Sunrise and Sunset is also due to these dust particles. Dust particles play important role in the process of condensation as water vapor changes to small drops on these particles.
Essay Type Questions:
Give brief introduction of elements of atmosphere.
Main Elements of Atmosphere – Followings are the main elements of atmosphere –
1. Temperature –
the meaning of temp, is how much hot is the air. According to day- night and seasons, the temp, of air changes continuously. Generally temp, decreases from equator to poles continuously, as on equator the Sun rays fall directly while on poles slant. No doubt, temp, increases at the equator. The unit of measurement of temp, is centigrade or Fahrenheit. The instrument used for measuring temp, is thermometer.
2. Air Pressure –
The weight of air on the different layer of earth is called air pressure. Maximum air pressure is at sea level and it decreases while going upwards from sea level.
3. Wind –
The flow of air from high pressure area to lower pressure is called wind. Wind is of three types –
- Permanent winds
- Seasonal winds
- Local winds.
4. Humidity –
The water in form of vapour when gets mixed up with air is called humidity. When water of reservoirs and plants evaporates, humidity is formed.
5. Rain –
The falling of water drops on earth is called rain. There are three types of rainfall –
- Mountain rain
- Convectional rain
- Cyclonic rain.