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Pollution of Air and Water — Class 8 CBSE Science MCQs with Solutions
Free Class 8 CBSE Science Pollution of Air and Water MCQs with step-by-step solutions. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — easy
Which gas is mainly responsible for the greenhouse effect?
A. oxygen
B. carbon dioxide ✓ Correct
C. nitrogen
D. helium
Solution: CO₂ traps heat in the atmosphere.
Q2 — easy
Water that is unfit for drinking is called:
A. potable
B. polluted ✓ Correct
C. distilled
D. mineral
Solution: Polluted water is unsafe to drink.
Q3 — easy
Which of these is a major source of air pollution?
A. planting trees
B. burning fossil fuels ✓ Correct
C. rainwater
D. solar energy
Solution: Burning fuels releases harmful gases.
Q4 — easy
Water fit for drinking is called:
A. potable water ✓ Correct
B. sewage
C. sea water
D. waste water
Solution: Potable water is safe to drink.
Q5 — hard
Carbon monoxide is a dangerous air pollutant because it:
A. smells strongly
B. reduces the blood's ability to carry oxygen ✓ Correct
C. is visible
D. is heavier than water
Solution: It binds to haemoglobin in place of oxygen.
Q6 — hard
Which practice best reduces water pollution from farms?
A. using more chemical fertilisers
B. using organic manure and controlled fertiliser use ✓ Correct
C. dumping waste into rivers
D. draining ponds
Solution: Less chemical runoff protects water bodies.
Q7 — hard
The Ganga Action Plan was launched mainly to:
A. build dams
B. reduce pollution of the river Ganga ✓ Correct
C. increase fishing
D. divert the river
Solution: It aimed to clean the Ganga.
Q8 — hard
Which is the best long-term step an individual can take to reduce air pollution?
A. use private cars daily
B. use public transport and plant trees ✓ Correct
C. burn waste at home
D. use more air conditioners
Solution: Fewer vehicles and more trees cut pollution.
Q9 — medium
The Taj Mahal is damaged by acid rain in a process called:
A. marble cancer ✓ Correct
B. eutrophication
C. global warming
D. sedimentation
Solution: Acid attacks marble, called marble cancer.
Q10 — medium
Excess nutrients in a lake cause rapid algae growth, known as:
A. filtration
B. eutrophication ✓ Correct
C. chlorination
D. evaporation
Solution: Algal blooms deplete oxygen in water.
Q11 — medium
Which method purifies water at home by killing germs using heat?
A. filtration
B. boiling ✓ Correct
C. sedimentation
D. decantation
Solution: Boiling kills most disease-causing microbes.
Q12 — medium
Chlorination of water is done to:
A. add taste
B. kill germs ✓ Correct
C. add minerals
D. increase hardness
Solution: Chlorine is a disinfectant.