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CBSE 8th Social Science Theme B - The Rise of the Marathas - New Model Questions Papers Study Material - QB365 Set A
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CBSE 8th Social Science Theme B - Reshaping India's Political Map - New Model Questions Papers Study Material - QB365 Set A
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Published on: 29/10/2025
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Questions + Answers key
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1.
Why does Kanpur city in Uttar Pradesh have one of the most polluted stretches of the Ganga river?
2.
Explain the Ganga Action Plan in short.
3.
Write full form of CNG and LPG
4.
How is untreated sewage the major cause of water pollution?
5.
What is recent climate change report?
6.
What has been done to reduce pollution in Delhi?
7.
For what purpose, bacteria present in faeces is used?
8.
The quality of air at various locations is monitored regularly by government and other agencies. In what way can you use these data?
9.
Combustion of fossil fuels generates a lot of air pollution. Can you suggest any two alternative sources of energy which do not cause any pollution?
10.
It is advised to use alternative fuels to reduce air pollution. What are alternative fuels?
11.
A part of radiation is absorbed by CO2, Write the this part.
12.
The use of excessive fertilisers and pesticides leads to the deficiency of an important substance in water. Name the substance.
13.
Run-off water from a garden is not considered a point source of pollution. Give reason.
14.
Microorganisms such as bacteria are also pollutants of water. In which category of pollutants, are they placed?
15.
Name two gases which are mainly responsible for acid rain.
16.
Groundwater also gets polluted by sewage. How?
17.
A fuel can be used in vehicles in place of petrol and diesel. Name it.
18.
We need to filter water before drinking. Give reason.
19.
Name any two water pollutants which are toxic for both plants and animals
20.
A gas in majorly responsible for greenhouse effect. Write the name of this gas.
21.
A phenomenon that occurs naturally benefits life on the earth. The excess of it causes global warming. Name the phenomenon.
22.
Air is a mixture of gases. Give the percentage of nitrogen and Oxygen in clear air.
23.
Respiratory problems are caused by which type of pollution?
24.
A gas is known to reduce the oxygen carrying capacity of blood. Mention its name
25.
Is smog an air pollutant?
26.
Mention two sources of air pollution that are not due to humans.
27.
A gas X is present in the stratosphere that prevents Y radiations of the sun from reaching the earth. This gas is getting depleted by CFCs. Identify X and Y.
28.
State whether acid rain affects the soil and plants.
29.
An alternative fuel for vehicles is CNG. Write its full form.
30.
Name the chemicals which are used in refrigerators and air conditioner and damage ozone layer when released in air.
1.
Kanpur city is situated at the bank of the river Ganga. Many people can be seen bathing, washing clothes, throwing garbage, idols of Gods, nonbiodegradables polythenes. In addition, Kanpur has more than 5000industries. They discharge toxic chemical waste into the river. Hence, Kanpur really makes the Ganga polluted.
2.
The Ganga is said to be the only holy river in India. It sustains most of the northern, central and eastern Indian populations. Recently a study by World Wide Fund (WWF) reports that the Ganga is an endangered river. The towns and cities through which it passes throw large quantities of garbage, untreated sewage, dead bodies etc. which make river dead. A plan launched in 1985 to save this river is Ganga Action Plan.
3.
CNG : Compressed Natural Gas.
LPG: Liquefied Petroleum Gas
4.
Sometimes untreated sewage is thrown directly into the rivers. It contains food wastes, detergents, micro-organisms etc. Thus, water gets contaminated with bacteria, fungi, virus, parasites which can cause diseases such as cholera, typhoid, jaundice etc.
5.
The recent climate change report gives us only a limited time to keep greenhouse gases at the present level. Otherwise, the temperature may rise by more than 2°C by the end of the century, a level considered dangerous
6.
Delhi is one of the most polluted cities in the world. It was choked by fumes released from automobiles running on diesel and petrol. A decision was taken to switch to fuels like CNG and unleaded petrol. These measures have resulted in cleaner air for the city.
7.
The bacteria present in the faeces are used as indicators of the quality of water.
8.
The quality of air at various locations is monitored regularly by government and other agencies. These data can be used to generate awareness about air pollution among people.
9.
Combustion of fossil fuels generates a lot of air pollution. Solar energy and wind energy are two alternative sources of energy which do not cause any pollution.
10.
Alternative fuels can be used in place of fossil fuels to reduce pollution, e.g. solar energy.
11.
Infrared radiation is absorbed by CO2
12.
The substance is oxygen
13.
Run-off from a garden is not considered a point source of pollution because this water does not have a specific location for its discharge pollutants.
14.
Microorganisms (pathogens) such as viruses are included in biological water pollutants.
15.
Sulphur dioxide and nitrogen dioxide are the two gases mainly responsible for acid rain.
16.
Untreated or inadequately treated sewageis major source of groundwater pollution. Sewage contains food wastes, detergents, microorganisms, etc which seeps into the ground to pollute groundwater.
17.
CNG can be used in place of petrol and diesel in vehicles.
18.
Water contains many disease carrying microbes and dissolved impurities that are not visible to unaided eyes. So, we need to filter water before drinking.
19.
Lead and arsenic are two water pollutants which are toxic for both plants and animals.
20.
Carbon dioxide (CO2) is majorly responsible for greenhouse effect
21.
The phenomenon is greenhouse effect
22.
Clear air contains about 78% nitrogen and 21% oxygen
23.
Air pollution causes respiratory problems.
24.
Carbon monoxide (CO) reduces the oxygen carrying capacity of blood.
25.
Smog is a deadly air pollutant formed by the combination of smoke and fog.
26.
Volcanoes and dust storms are natural sources of air pollution
27.
X is ozone, Y is Ultraviolet (UV) rays.
28.
Acid rain affects both the soil and plants. It decreases the pH value of soil, thus making the soil acidic which is harmful for plants
29.
CNG is Compressed Natural Gas.
30.
Chlorofluorocarbons (CFCs) are the chemical compounds which are used in refrigerators, air conditioners and aerosol sprays, and damage ozone layer when released in air.
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