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  • Class 8 Science Study Material

An Educational platform for Preparation and Practice Class 8. Kidsfront provide unique pattern of learning Science with free online comprehensive study material in the form of QUESTION & ANSWER for each Chapter of Science for Class 8. This study material help Class 8, Science students in learning every aspect of Pollution Of Air And Water . Students can understand Pollution Of Air And Water concept easily and consolidate their learning by doing Online Practice Tests on Science,Pollution Of Air And Water chapter repeatedly till they excel in Class 8, Pollution Of Air And Water . Free ONLINE PRACTICE TESTS on Class 8, Pollution Of Air And Water comprise of Hundreds of Questions on Pollution Of Air And Water , prepared by the highly professionals team. Every repeat test of Pollution Of Air And Water will have new set of questions and help students to prepare themselves for exams by doing unlimited Online Test exercise on Pollution Of Air And Water . Attempt ONLINE TEST on Class 8,Science,Pollution Of Air And Water in Academics section after completing this Pollution Of Air And Water Question Answer Exercise.


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Pollution Of Air And Water
The problem caused by smog is

a) Respiratory problem.
b) Digestive problem.
c) Heart problem.
d) Excretory problem.



Answer
Solution
Correct Answer Is : Respiratory problem.
Solution Is : Smog is made up of smoke and fog. Smoke may contain oxides of nitrogen which combine with other air pollutants and fog to form smog. The smog causes breathing difficulties such as asthma, cough and wheesing in children.
The addition of undesired and harmful substances in our environment is called

a) Purification.
b) Population.
c) Pollution.
d) Suffocation.



Answer
Solution
Correct Answer Is : Pollution.
Solution Is : Pollution is the addition of contaminants into an environment that cause harm to living organisms and non-living components.
The gas that forms the major part of the air is

a) Oxygen.
b) Nitrogen.
c) Carbon dioxide.
d) Ozone.



Answer
Solution
Correct Answer Is : Nitrogen.
Solution Is : In air, nitrogen is about 78% and oxygen is about 21% by volume. Carbon dioxide and ozone are present in small quantity.
The contamination of air by unwanted and harmful substances is known as

a) Noise pollution.
b) Air pollution.
c) Water pollution.
d) Soil pollution.



Answer
Solution
Correct Answer Is : Air pollution.
Solution Is : Air pollution is the contamination of air by the impurities which adversely affect the living organisms and the non-living components.
Smoke is

a) An air pollutant.
b) A water pollutant.
c) A sound pollutant.
d) A soil pollutant.



Answer
Solution
Correct Answer Is : An air pollutant.
Solution Is : The substances which contaminate the air are called air pollutants. Sometimes, such substances may come from natural sources like smoke and dust, arising from forest fires or volcanic eruptions.
Incomplete combustion of fuels produces

a) Carbon monoxide gas.
b) Oxygen gas.
c) Nitrogen gas.
d) Argon gas.



Answer
Solution
Correct Answer Is : Carbon monoxide gas.
Solution Is : Incomplete combustion of fuels produces carbon monoxide which is a poisonous gas. It decreases the oxygen carrying capacity of blood.
Ozone is a

a) Liquid.
b) Solid.
c) Gas.
d) Metal.



Answer
Solution
Correct Answer Is : Gas.
Solution Is : Ozone is a gas, which forms a layer in the atmosphere. The ozone layer protects us from harmful ultraviolet rays of the sun.
Ozone layer is depleting due to the presence of

a) Nitrogen dioxide.
b) Carbon monoxide.
c) Sulphur dioxide.
d) Chlorofluorocarbons.



Answer
Solution
Correct Answer Is : Chlorofluorocarbons.
Solution Is : Chlorofluorocarbons (CFCs) introduced in the air from aerosol sprays and refrigerating equipments damage the ozone layer of the atmosphere. Nitrogen dioxide, carbon monoxide and sulphur dioxide are air pollutants but they do not damage the ozone layer.
The Taj Mahal is being affected because of

a) Noise pollution.
b) Air pollution.
c) Water pollution.
d) Sound pollution.



Answer
Solution
Correct Answer Is : Air pollution.
Solution Is : The colour of white marble is affected by air pollution and not by water, noise or sound pollution. Polluted air contains sulphur dioxide and nitrogen dioxide, which forms acid rain. The acid rain corrodes the Taj mahal.
Which of the following is a poisonous gas forming acid rain and emitted by Mathura oil refinery

a) CO2
b) CO
c) O2
d) SO2



Answer
Solution
Correct Answer Is : SO2
Solution Is : SO2 is a poisonous gas. It reacts with the water vapour present in air to form sulphuric acid. The rain containing sulphuric acid and nitric acid is called Acid rain. CO2 and O2 are not poisonous gases. CO is a poisonous gas but it does not form acid rain.