Pollution

PYQs (Q1–10)

1. Which gas is primarily responsible for acid rain?
   a) Carbon monoxide
   b) Sulphur dioxide
   c) Methane
   d) Ozone
   ✅ b) Sulphur dioxide
   Explanation: SO₂ reacts with water to form sulfuric acid. (BPSC 2020)

2. Which of the following is a major greenhouse gas?
   a) O₂
   b) CO₂
   c) N₂
   d) H₂
   ✅ b) CO₂
   Explanation: Carbon dioxide is a key contributor to global warming. (BPSC CDPO 2019)

3. Which pollutant is mainly emitted by petrol vehicles?
   a) Lead
   b) Sulphur dioxide
   c) Methane
   d) Ozone
   ✅ a) Lead
   Explanation: Leaded petrol was a major source before its phase-out. (BPSC Assistant 2018)

4. The Taj Mahal is affected by which kind of pollution?
   a) Noise pollution
   b) Water pollution
   c) Air pollution
   d) Soil pollution
   ✅ c) Air pollution
   Explanation: SO₂ and acid rain cause yellowing of white marble. (BPSC 64th Prelims)

5. Water pollution in India is mostly caused by:
   a) Oil spills
   b) Industrial effluents
   c) Soil erosion
   d) Climate change
   ✅ b) Industrial effluents
   Explanation: Untreated industrial discharge is a major cause. (BPSC 65th Prelims)

6. Which type of pollution causes hearing loss?
   a) Air
   b) Water
   c) Noise
   d) Thermal
   ✅ c) Noise
   Explanation: Prolonged exposure to sound >85 dB causes hearing damage. (BPSC 2023)

7. Which of these gases is not a greenhouse gas?
   a) Methane
   b) Nitrous oxide
   c) Hydrogen
   d) Carbon dioxide
   ✅ c) Hydrogen
   Explanation: Hydrogen does not trap heat in the atmosphere. (BPSC Teacher 2023)

8. Which act controls water pollution in India?
   a) Environment Protection Act
   b) Air (Prevention & Control) Act
   c) Water Act, 1974
   d) Wildlife Protection Act
   ✅ c) Water Act, 1974
   Explanation: It was the first major environmental law. (BPSC 2022)

9. BOD is a measure of:
   a) Basic Oxygen Demand
   b) Biochemical Oxygen Demand
   c) Biological Organism Demand
   d) Best Oxygen Dilution
   ✅ b) Biochemical Oxygen Demand
   Explanation: Indicates organic pollution in water. (BPSC 2018)

10. Which of these is the chief source of noise pollution in cities?
    a) Industrial machines
    b) Traffic
    c) Airplanes
    d) Loudspeakers
    ✅ b) Traffic
    Explanation: Vehicle horns and engines are major contributors. (BPSC 2021)

11. Which of the following is a non-biodegradable pollutant?
    a) Sewage
    b) Vegetable waste
    c) Plastic
    d) Paper
    ✅ c) Plastic
    Explanation: Plastics do not decompose easily and persist in the environment.

12. Ozone depletion is caused by:
    a) Lead
    b) CFCs
    c) Methane
    d) Carbon dioxide
    ✅ b) CFCs
    Explanation: CFCs break down ozone molecules in the stratosphere.

13. Which of the following is an indicator of water pollution?
    a) Algal bloom
    b) Fish growth
    c) Rainfall
    d) Increased oxygen
    ✅ a) Algal bloom
    Explanation: Excess nutrients lead to algal blooms, depleting oxygen.

14. The Air Quality Index (AQI) measures:
    a) Sound
    b) Temperature
    c) Air pollution
    d) Wind speed
    ✅ c) Air pollution
    Explanation: AQI indicates air quality and pollutant levels.

15. Which pollutant is most responsible for respiratory issues?
    a) CO₂
    b) NOx
    c) Particulate Matter (PM2.5)
    d) O₃
    ✅ c) Particulate Matter (PM2.5)
    Explanation: Fine particles penetrate lungs and cause asthma, bronchitis.

16. The Taj Mahal is affected by:
    a) Carbon monoxide
    b) Sulphur dioxide
    c) Methane
    d) Ozone
    ✅ b) Sulphur dioxide
    Explanation: SO₂ from industries causes acid rain, damaging marble.

17. Thermal pollution mainly affects:
    a) Soil fertility
    b) Water temperature
    c) Air circulation
    d) Ozone layer
    ✅ b) Water temperature
    Explanation: Discharge of hot water raises river/lake temperatures.

18. Minamata disease is caused due to pollution by:
    a) Arsenic
    b) Mercury
    c) Lead
    d) Iron
    ✅ b) Mercury
    Explanation: Mercury-contaminated fish caused neurological disorders in Japan.

19. The most polluted river in India (by BOD) is:
    a) Narmada
    b) Godavari
    c) Yamuna
    d) Sutlej
    ✅ c) Yamuna
    Explanation: High BOD indicates organic pollution in Yamuna.

20. Excess fluoride in water causes:
    a) Cancer
    b) Dental and skeletal fluorosis
    c) Asthma
    d) Typhoid
    ✅ b) Dental and skeletal fluorosis
    Explanation: Fluoride affects teeth and bones if in excess.

21. Which pollutant causes blue baby syndrome?
    a) Lead
    b) Nitrates
    c) Mercury
    d) Arsenic
    ✅ b) Nitrates
    Explanation: Excess nitrates reduce oxygen in infant blood.

22. Ganga Action Plan was launched in:
    a) 1980
    b) 1985
    c) 1990
    d) 1995
    ✅ b) 1985
    Explanation: It was India’s first major river-cleaning project.

23. Which is a biodegradable pollutant?
    a) Detergent
    b) Polythene
    c) Sewage
    d) Pesticide
    ✅ c) Sewage
    Explanation: Organic sewage can be decomposed by microbes.

24. Major source of indoor air pollution is:
    a) Industry
    b) Vehicles
    c) Biomass burning
    d) Mining
    ✅ c) Biomass burning
    Explanation: In rural homes, chulhas release harmful smoke indoors.

25. Which gas causes photochemical smog?
    a) CO
    b) CH₄
    c) O₃
    d) NO₂
    ✅ d) NO₂
    Explanation: NO₂ reacts with sunlight and hydrocarbons to form smog.

26. What causes e-waste pollution?
    a) Food waste
    b) Organic garbage
    c) Electronic gadgets
    d) Wood
    ✅ c) Electronic gadgets
    Explanation: Old phones, laptops, and wires are e-waste.

27. Which of the following is not a greenhouse gas?
    a) CO₂
    b) CH₄
    c) N₂
    d) H₂O vapor
    ✅ c) N₂
    Explanation: Nitrogen is not a greenhouse gas.

28. Which act deals with water pollution in India?
    a) Environment Act 1986
    b) Water Act 1974
    c) Air Act 1981
    d) Forest Act 1927
    ✅ b) Water Act 1974
    Explanation: It regulates and prevents water pollution.

29. Pollutants released by burning fossil fuels include:
    a) CO, NOx, SO₂
    b) H₂O
    c) NH₄OH
    d) All of the above
    ✅ a) CO, NOx, SO₂
    Explanation: These gases come from coal and petroleum combustion.

30. Carbon monoxide is dangerous because it:
    a) Burns skin
    b) Displaces oxygen in blood
    c) Causes cancer
    d) Smells bad
    ✅ b) Displaces oxygen in blood
    Explanation: CO binds with hemoglobin more strongly than oxygen.

31. Water pollution due to detergents is mainly due to:
    a) Sulphates
    b) Nitrates
    c) Phosphates
    d) Ammonia
    ✅ c) Phosphates
    Explanation: Phosphates cause eutrophication and algal blooms.

32. Noise is considered pollution when its level exceeds:
    a) 50 dB
    b) 60 dB
    c) 70 dB
    d) 85 dB
    ✅ d) 85 dB
    Explanation: Noise over 85 dB can harm hearing.

33. Most solid waste in India comes from:
    a) Agriculture
    b) Industry
    c) Households
    d) Construction
    ✅ c) Households
    Explanation: Municipal solid waste is largely domestic in origin.

34. Which metal is released from batteries as e-waste?
    a) Aluminium
    b) Copper
    c) Lead
    d) Magnesium
    ✅ c) Lead
    Explanation: Lead-acid batteries are a major pollution source.

35. Thermal power plants cause:
    a) Noise pollution
    b) Soil pollution
    c) Thermal and air pollution
    d) Only water pollution
    ✅ c) Thermal and air pollution
    Explanation: They release heat and smoke from coal burning.

36. Which of these is a carcinogenic air pollutant?
    a) CO
    b) Benzene
    c) NO₂
    d) CH₄
    ✅ b) Benzene
    Explanation: Benzene is a known cancer-causing compound.

37. Which pollutant reduces the oxygen-carrying capacity of blood?
    a) Nitrogen
    b) Carbon monoxide
    c) CO₂
    d) Helium
    ✅ b) Carbon monoxide
    Explanation: CO binds with hemoglobin more effectively than O₂.

38. Which of the following causes soil pollution?
    a) Excess fertilizers
    b) Rain
    c) Winds
    d) None
    ✅ a) Excess fertilizers
    Explanation: Chemical fertilizers and pesticides degrade soil quality.

39. The term “Smog” is a combination of:
    a) Smoke and fog
    b) Snow and fog
    c) Sun and fog
    d) Steam and gas
    ✅ a) Smoke and fog
    Explanation: Smog forms from smoke + fog + pollutants.

40. pH of polluted rainwater is usually:
    a) 7
    b) Less than 5.6
    c) 9
    d) Neutral
    ✅ b) Less than 5.6
    Explanation: Acid rain has pH < 5.6 due to acidic gases.

41. Which pollutant is most responsible for global warming?
    a) CO₂
    b) SO₂
    c) NO₂
    d) O₃
    ✅ a) CO₂
    Explanation: Carbon dioxide traps heat in the atmosphere.

42. Which Indian city often ranks highest in air pollution?
    a) Kolkata
    b) Mumbai
    c) Delhi
    d) Bhopal
    ✅ c) Delhi
    Explanation: Delhi’s AQI often crosses hazardous levels.

43. The CPCB is under which Ministry?
    a) Agriculture
    b) Environment
    c) Water Resources
    d) Energy
    ✅ b) Environment
    Explanation: CPCB functions under the Ministry of Environment, Forest and Climate Change.

44. Which act covers all forms of pollution in India?
    a) Water Act
    b) Air Act
    c) Environment Protection Act
    d) Forest Act
    ✅ c) Environment Protection Act
    Explanation: It’s an umbrella law covering all types of pollution.

45. Which of these is a radioactive pollutant?
    a) Radon
    b) Carbon
    c) Sulphur
    d) Mercury
    ✅ a) Radon
    Explanation: Radon gas is a radioactive pollutant in buildings.

46. Which pollution can lead to global dimming?
    a) Light
    b) Air
    c) Water
    d) Noise
    ✅ b) Air
    Explanation: Particulate matter blocks sunlight, reducing brightness.

47. Which of the following is a biodegradable waste?
    a) Paper
    b) Glass
    c) Plastic
    d) E-waste
    ✅ a) Paper
    Explanation: Paper decomposes naturally.

48. Which of the following is linked to ozone depletion?
    a) Acid rain
    b) Skin cancer
    c) Asthma
    d) Greenhouse effect
    ✅ b) Skin cancer
    Explanation: UV rays increase when ozone is depleted.

49. Bhopal gas tragedy involved:
    a) Ammonia
    b) Methyl isocyanate
    c) Benzene
    d) Cyanide
    ✅ b) Methyl isocyanate
    Explanation: MIC leak in 1984 caused thousands of deaths.

50. Pollution control day is observed on:
    a) October 2
    b) December 2
    c) March 21
    d) June 5
    ✅ b) December 2
    Explanation: It commemorates the Bhopal gas tragedy.