ENVIRONMENTAL POLLUTION & CONTROL MCQS 18

ENVIRONMENTAL POLLUTION & CONTROL  MCQS 18

1. Pick out the wrong statement pertaining to 'green house' for the plants.
(A) 'Green house' (made of glass) allows visible sunlight (i.e., short wavelength solar radiation like ultra-violet rays) to pass through the glass and heat up the soil thereby warming up plants inside it
(B) The emitted longer wavelength radiation (e.g., infrared) is partly reflected and partly absorbed by the glass of the green house
(C) 'Green house effect' in earth's atmosphere is due to increasing CO2 level in atmosphere, where CO2 acts like the glass of 'green house' thereby warming up the earth's surface
(D) 'Green house' is colder than the outside atmosphere
Answer: Option D

2. The amount of chemical coagulant added for treatment of polluted water __________ with increase in temperature of the polluted water to be treated.
(A) Decreases
(B) Increases
(C) Remain constant
(D) May increase or decrease; depends on the chemical characteristics of polluted water
Answer: Option A

3. In the context of the chemical process industries, the term BOD is normally associated with the
(A) Characterisation of solid wastes
(B) Organic concentration in gaseous effluents
(C) Characterisation of liquid effluents
(D) Characterisation of boiler feed water
Answer: Option C

4. Foaming and priming in boiler operation can be reduced by reduction in __________ in feed water.
(A) Turbidity
(B) Color (Hazen)
(C) Total solids
(D) All (A), (B) & (C)
Answer: Option D

5. Iron & manganese present as pollutant in water cannot be removed by
(A) Ion exchange process
(B) Oxidation followed by settling & filtration
(C) Lime soda process or manganese zeolite process
(D) Chlorination
Answer: Option D

6. Which of the following is a green house gas other than CO2?
(A) Methane
(B) Nitrous oxide
(C) Chlorofluoro carbons (CFC)
(D) All (A), (B) and (C)
Answer: Option D

7. Which is the most practical and economical method for removal of suspended solid matter from polluted water?
(A) Sedimentation
(B) Skimming off
(C) Chlorination
(D) Biological oxidation
Answer: Option A

8. Aerodynamic noise resulting from turbulent gas flow is the most prevalent source of valve noise in fluid flow control. It is caused due to
(A) Reynold stresses
(B) Shear forces
(C) Both (A) & (B)
(D) Neither (A) nor (B)
Answer: Option C

9. When the concentration of SO2 in air is greater than __________ ppm, it gives a pungent smell.
(A) 0.01
(B) 0.1
(C) 1
(D) 4
Answer: Option D

10. Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds __________ percent (by volume).
(A) 1
(B) 3
(C) 7
(D) 20
Answer: Option D