Q 1 – What is the Atmosphere ?
Ans. The atmosphere is the blanket of air that surrounds the earth.
- Nitrogen
- Oxygen
Q 2 – Which two gas make the hulk of the atmosphere ?
Ans. Carbon dioxide
Q 3 – Which gas creates the Greenhouse effects in the atmosphere ?
Ans. Weather is the total of atmospheric conditions of a specific place, at a specific time, regarding temperature, humidity, air pressure, clouds, winds, etc.
Q 4 – What is the weather?
Ans. three types of rainfall are:
- Cyclonic or Frontal rainfall.
- Orographic rainfall
- Convectional rainfall
Q 5 – Name three types of rain fall ?
Ans.
Q 6 – What is air pressure ?
Ans. Air pressure: Air has weight and exerts pressure. Hence, air pressure is an impact which occurs due to air weight.
Q 7 – How does carbon dioxide create green house effect?
Ans. Crbon dioxide creates greenhouse effect by trappeing the heat radiated from the earth.
Q 8 – What is the significance of greenhouse gas?
Ans. Without the greenhouse gas the earth would have been too cold to line in.
Q 9 – What happens when air is heated?
Ans. When air is heated, it expands, becomes lighter and goes up.
Q 10 – What is the nature of cold air?
Ans. It has tendency to go down.
Q 11 – Why do green plants use carbon dioxide?
Ans. Green plants use carbon dioxide to make their food and release oxygen.’
Q 12 – What is an important feature of Stratosphere?
Ans. Stratosphere contains a layer of ozone gas.
Q 13 – How is ozone important for us?
Ans. It protects us from the harmful effect of the sunrays.
Q 14 – What is temperature?
Ans. The degree of hotness and coldness of the air is known as temperature.
Q 15 – What is insolation?
Ans. Insolation is the incoming solar energy intercepted by the earth.
Q 16 – Why is there no air pressure on the moon?
Ans. There is no air on the moon and therefore no air pressure.
Q 17 – Where is air pressure highest?
Ans. Air pressure is highest at the sea level.
Q 18 – How does air move?
Ans. Air moves from high pressure areas to low pressure areas.
Q 19 – Name three types of winds.
Ans.
- Permanent winds
- Seasonal winds
- Local winds.
Q 20 – What is the hot and dry wind of northern planes of India called?
Ans. It is called loo.
Q 21 – What is called humidity?
Ans. Moisture in the air at any time is called humidity.
Q 22 – Why do we feel uncomfortable on a humid day?
Ans. It is because sweat from our body does not evaporate easily.
Q 23 – How is the flooding of low lying areas caused?
Ans. When trees on hillsides are cut, rainwater flows down the bare mountains. This causes flooding of low-lying areas.
Q 24 – Name various forms of precipitation.
Ans.
- Rain
- Snow
- Sleet
- Hail
Q 25 – How is a wind named?
Ans. A wind is named after the direction from which it blows. ‘
Q 26 – Give an account of the composition of the atmosphere.
Ans. Our atmosphere is composed of mainly two gases—nitrogen (78%) and oxygen (21%). Other gases like carbon dioxide, helium, ozone, orgon, and hydrogen are found in lesser quantities. Apart from these gases, tiny dust particles are also present in the air.
Q 27 – How do Bacteria help plants use nitrogen?
Ans. Nitrogen is essential for the survival of the plant. But plants cannot take nitrogen directly from the air. Bacteria, that live in the soil and roots of some plants, take nitrogen from the air and change its form so that plants can use it.
Q 28 – How does nature balance our life? What is the result if this balance is disturbed?
Ans. Green plants use carbon dioxide to make their food and release oxygen. Humans or animals release carbon dioxide. The amount of carbon dioxide released by humans or animals seems to be equal to the amount used by the plants which make a perfect balance. But this balance is disturbed by the burning of fuels, which add billions of tons of carbon dioxide in the atmosphere. As a result, the increased volume of carbon dioxide is affecting the earth’s weather and climate.
Q 29 – Why is temperature in cities much higher than that of villages ?
Ans. In cities, we find high-rise buildings. The concrete and metals in these buildings and the asaphalt of roads get heated up during the day. This heat is released during the night.
Another reason is that the crowded high-rise buildings of the cities trap the warm air and thus raise the temperature of the cities.
Q 30 – Write a short note on the distribution of air pressure in the atmosphere
Ans. Air pressure is the pressure exerted by the weight of air on the earth’s surface. As we go up the layers of the atmosphere, the pressure falls rapidly. The air pressure is highest at sea level and decreases with height. Horizontally the distribution of air pressure is influenced by the temperature of the air at a given place. In areas where the temperature is high the air gets heated and rises. This creates a low-pressure area. In areas having lower temperatures, the air is cold, hence, it is heavy. Heavy air sinks and creates a high-pressure area.
Q 31 – Why do astronauts wear special protective suits when they go to the moon?
Ans. Astronauts wear special protective space suits filled with air when they go to the moon. If they did not wear these space suits, the counter-pressure exerted by the body of the astronauts would make the blood vessels burst. The astronauts would bleed.
Q 32 – How is rainfall important for us? What happens when there is excess rain?
Ans. Rainfall is very important for the survival of plants and animals. It brings freshwater to the earth’s surface. If rainfall is less, there is water scarcity which sometimes causes drought-like situations. If there is excess rain, floods take place which makes the life of the affected people miserable.
Q 33 – Give an account of the different layers of the atmosphere.
Ans. 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 conditions for flying aeroplanes. It contains a layer of ozone gas which protects us from the harmful effect of the sunrays.
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 are 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.
Q 34 – What is wind? Mention its different types.
Ans. The wind is the movement of air from the high-pressure areas to low-pressure areas. It is divided into three types:
- Permanent winds
- Seasonal winds
- Local winds
1. Permanent winds. The trade winds, westerlies, and easterlies are the permanent winds. These blow constantly throughout the year in a particular direction.
2. Seasonal winds. These winds change their direction in different seasons. For example monsons in India.
3. Local winds. These winds blow only during a particular period of the day or year in a small area. For example land and sea breeze. Loo is a local wind which hot and dry and blows in the northern plains of India during summers.
Q 35 – Why is the atmosphere essential for life?
Ans. All living beings on this earth depend on the atmosphere for their survival. It provides us the air we breathe and protects us from the harmful effects of the sun’s rays. Without this blanket of protection, we would be baked alive by the heat of the sun during day and get frozen during night. So it is this mass of air that has made the temperature on
the earth liveable.
Q 36 – What are the harmful effects arising from the greenhouse effect?
Ans. When its level in the atmosphere increases due to factory smoke or car fumes, the heat retained increases the temperature of the earth. This is called global warming. This rise in temperature causes the snow in coldest parts of the world to melt. As a result the sea level rises, causing floods in the coastal areas. There may be drastic changes in the climate of a place leading to extinction of some plants and animals in the long run.
Q 37 – Discuss the importance of stratosphere?
Ans. The importance of stratosphere are:
- Above the troposphere lies the stratosphere. It extends up to a height of 50 km. This
layer is almost free from clouds and associated weather phenomenon, making conditions most ideal for flying airplanes. - One important feature of stratosphere is that it contains a layer of ozone gas which
protects us from the harmful effect of the sun rays.
Q 38 – Write a short note on the distribution of air pressure in atmosphere?
Ans. Air pressure is defined as the pressure exerted by the weight of air on the earth’s surface. As we go up the layers of atmosphere, the pressure falls rapidly. The air pressure is highest at sea level and decreases with height. Horizontally the distribution of air pressure is influenced by temperature of air at a given place. In areas where
temperature is high the air gets heated and rises. This creates a low-pressure area. Low pressure is associated with cloudy skies and wet weather
Q 39 – How does nature maintain a balance of oxygen and carbon dioxide in the atmosphere? What is the result of this balance get disturbed?
Ans. Oxygen is the second most plentiful gas in the air. Humans and animals take oxygen from the air as they breathe. Green plants produce oxygen during photosynthesis.
In this way oxygen content in the air remains constant. If we cut trees then this balance gets disturbed. Carbon dioxide is another important gas. Green plants use carbon dioxide to make their food and release oxygen. Humans or animals release carbon dioxide. The amount of carbon dioxide released by humans or animals seems to be equal to the amount used by the plants which make a perfect balance. However, the balance is upset by burning of fuels, such as coal and oil. They add billions of tons of carbon dioxide into the atmosphere each year. As a result, the increased volume of carbon dioxide is affecting the earth’s weather and climate.
Q 40 – How does carbon dioxide create the greenhouse effect?
Ans. Carbon dioxide released in the atmosphere creates a greenhouse effect by trapping the heat radiated from the earth.