Pollution Control Questions and Answers – Sources and Classification of Air Pollutants – Set 2

This set of Pollution Control Multiple Choice Questions & Answers (MCQs) focuses on “Sources and Classification of Air Pollutants – Set 2”.

1. Agriculture activities release which of the following particulates?
a) Sulphur dioxide
b) Hydrocarbons
c) Fumes
d) Fly ash
View Answer

Answer: d
Explanation: Fumes are not released from crop spraying and burning of fields. Both, hydrocarbons and sulphur dioxides are gaseous in nature. Agricultural activities do, however, release fly ash into the atmosphere.

2. Which of the following is not an example of natural particulate matter?
a) Dust from soil
b) Suspended sea salt
c) Domestic dust
d) Volcanic dust
View Answer

Answer: c
Explanation: Dust from domestic sources fall into the anthropogenic sources of particulate matter. Soil dust, volcanic dust, airborne sea salt are all examples of natural sources of particulate matter, dust in this case.

3. Gases in the atmosphere can convert to aerosols.
a) True
b) False
View Answer

Answer: a
Explanation: Gases, from both anthropogenic and natural sources, may convert to aerosols. This process happens upon a chemical reaction. An example is the conversion of gaseous sulphur dioxide to sulphate particles in the atmosphere.

4. Iodine-131 may be emitted from which of the following sources?
a) Mineral ore processing
b) Nuclear sources
c) Combustion processes
d) Chemical manufacture
View Answer

Answer: b
Explanation: Iodine-131 is a radioactive gas released from various nuclear energy production stages. These production stages can be during the fuel preparation, or maintenance, or in the event of a disaster.

5. What is the retention time of sulphur dioxide in the atmosphere?
a) 4 hours
b) 4 days
c) 4 months
d) 4 years
View Answer

Answer: b
Explanation: Retention time is the time for which a gas particle remains in the atmosphere upon emission. The retention time of sulphur dioxide is low, about four days. It usually gets converted into sulphates or sulphuric acid.

6. If the natural concentration of carbon dioxide in the atmosphere is 420ppm, what is its volume concentration?
a) 0.42
b) 0.042
c) 0.0042
d) 0.00042
View Answer

Answer: d
Given, yppm = 420
Volume concentration (ppm), yppm = yp * 106
Therefore, yp = yppm * 10-6
yp = 420 * 10-6
yp = 0.00042.

7. What is the primary source of organic vapours?
a) Domestic burning
b) Combustion processes
c) Atmospheric reactions
d) Mineral ore processing
View Answer

Answer: b
Explanation: The primary source of organic vapours is combustion processes. Although domestic burning and atmospheric reactions do give rise to their formation, they are not primary sources.

8. Which of the following is not an example of organic vapours?
a) Metal Hydrides
b) Benzene
c) Acetylenes
d) Paraffins
View Answer

Answer: a
Explanation: Hydrides are examples of inorganic vapours. Benzene, acetylenes, and paraffins are all examples of organic vapours. Hydrides can also be organic in nature, but the option isn’t given.

9. How are aldehydes primarily formed?
a) In the oceans
b) In the atmosphere
c) Complete combustion of fuels
d) Incomplete combustion of fuels
View Answer

Answer: d
Explanation: Incomplete combustion of fuels results in the primary source of formation of aldehydes. Aldehydes may also be produced in the atmosphere, but this is not a primary source.

10. What is the common range of natural air contaminants like pollen grain?
a) 5 micrometres to 50 micrometres
b) 10 micrometres to 50 micrometres
c) 10 micrometres to 100 micrometres
d) 50 micrometres to 100 micrometres
View Answer

Answer: b
Explanation: The size of pollen grain particle diameters ranges from 10 micrometres to 50 micrometres. Uncommonly, some may be as small as 5 micrometres or as large as 100 micrometres.

11. Why is the emission of air pollutants from natural sources so concerning?
a) They cause global warming
b) Their emissions are higher
c) Their concentrations are higher
d) They cause health problems
View Answer

Answer: c
Explanation: Natural emissions are comparable to anthropogenic emissions, but their distribution is evenly throughout the planet. Anthropogenic emissions are concentrated in certain areas, overwhelming local and regional sinks.

12. What are mists made of?
a) Liquid particles
b) Solid particles
c) Gaseous particles
d) Semi-solid particles
View Answer

Answer: a
Explanation: Mists are neither made of solid particles, nor are they made of gaseous particles. They are made up of liquid particles suspended in the air. A significant feature of mists is that the suspended liquid droplets are large in size.

13. Volcanic dust is the largest contributor to natural air pollutants.
a) True
b) False
View Answer

Answer: b
Explanation: Volcanic dust is not the primary source of natural air pollutants. This title belongs to sea-salt spray. This is because volcanic eruptions are sporadic events, while sea-salt sprays are continuous.

14. How are fumes formed?
a) Condensation of liquids
b) Solidification of liquids
c) Condensation of gases
d) Evaporation of liquids
View Answer

Answer: c
Explanation: Fumes are suspended solid particles that form when gases condense. The origin of these gases is the melting of solids in industries. Fumes are formed predominantly from industrial sources.

15. What is the primary industrial source of dust?
a) Processing stage
b) Waste treatment and disposal
c) Size separation operations
d) Size reduction operations
View Answer

Answer: d
Explanation: The primary industrial source of dust are size reduction operations. Size reduction operations are mainly crushing and grinding of organic and inorganic substances for further processing.

Sanfoundry Global Education & Learning Series – Pollution Control.

To practice all areas of Pollution Control, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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