250+ TOP MCQs on Air Pollution and Answers

Power Systems Multiple Choice Questions on “Air Pollution”.

1. Which of the following power plant causes highest amount of air pollution?
A. Thermal power plant
B. Hydroelectric power plant
C. Nuclear power plant
D. Geothermal power plant
Answer: A
Clarification: The major contribution of electrical power generation is from thermal power plant. The thermal power plant definitely contribute to economic growth but they bring with it like air and water pollution. Thermal power plant mostly causes air pollution by the emission of flue gases into air.

2. Which of the following gas is not emitted during combustion of coal?
A. Oxides of sulphur
B. Oxides of Nitrogen
C. Oxides of Mercury
D. Oxides of carbon
Answer: C
Clarification: Thermal power plant emit large amount of harmful gases such a Sulphur dioxide, nitrogen oxide, CO, CO₂, certain hydrocarbons and particulates during the combustion of fossil fuels. There is no any emission of oxides of mercury.

3. Which of the following pollutants emitted by thermal power plant causes irritation in Eyes?
A. Oxides of sulphur
B. Oxides of Nitrogen
C. Oxides of Mercury
D. Oxides of carbon
Answer: B
Clarification: At high temperatures existing in the flame core of high power boilers, the nitrogen of fuel and air may partially be oxidised to form nitrogen oxides. These are toxic and produce a sharp irritating effect especially on the mucous membrane of the eye.

4. Which of the following pollutants emitted by thermal power plant is a cause of global warming?
A. NO
B. CO₂
C. SO₂
D. NO₂
Answer: B
Clarification: Carbon monoxide and carbon dioxide are also emitted during the combustion of coal. Carbon monoxide is very toxic pollutant but it gets converted into carbon dioxide in open atmosphere surrounding the power station. On the other hand carbon dioxide has been identified as major cause of global warming.

5. Which of the following pollutant causes acid rain?
A. NO
B. CO₂
C. SO₂
D. NO₂
Answer: C
Clarification: The Sulphur Dioxide emitted by thermal power plant gradually oxides to sulphur trioxide under the influence of Sunlight. This in turn interact with atmospheric moisture and forms sulphuric acid. This sulphuric acid later causes acid rain.

6. Which of the following is mostly affected by thermal power plant pollutants?
A. Lithosphere
B. Atmosphere
C. Hydrosphere
D. Exosphere
Answer: B
Clarification: The thermal power plant mostly causes air pollution by the emission of harmful flue gases. So, it can be said that thermal power plant mostly pollutes our atmosphere.

7. Hydroelectric power plants with limited storage are suitable to supply __________
A. Base load
B. Peak load
C. Base load and Peak load
D. Average load
Answer: C
Clarification: The hydropower plant should be employed for supplying base load. But hydro power plants with limited water storage cannot supply base load. Hence they are suitable for peak loads.

8. Nuclear power plants are suitable only for load factor over _________
A. 0.5
B. 0.7
C. 0.3
D. 0.8
Answer: D
Clarification: Nuclear power plant is not suitable for variable load operation as the reactor cannot be easily controlled to respond quickly to load variations. Such a plant is used as base load plant only operating at high load factors of over 0.8.

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