Engineering Questions with Answers - Multiple Choice Questions

Environmental Engineering MCQ – Effects of Air Pollution, Design of Stack Height

1 - Question

Which of the following is not a part of photochemical smog?
a) NO2
b) O3
c) PAN
d) SPM

View Answer

Answer: d
Explanation: Photochemical smog includes NO2, O3 and PAN. The damage to vegetation is caused by NO2, O3 and PAN.




2 - Question

Which air pollutant cause corrosion of building?
a) SO2
b) SO3
c) CO
d) NO2

View Answer

Answer: a
Explanation: SO2 is a colorless and irritant gas that causes corrosion of building.




3 - Question

Which of the following air pollutant effects plants the most?
a) Fluorine
b) SO2
c) PAN
d) HCl

View Answer

Answer: a
Explanation: Fluorine is the most dangerous air pollutant that affects plant, whereas SO2, PAN and HCl effects the leaf of the plant.




4 - Question

The size of cigarette particles is ______________
a) 1μm
b) 10μm
c) <1μm d) >10μm

View Answer

Answer: c
Explanation: Cigarette particles are <1μm and >25% particles are deposited in the lungs.




5 - Question

Concentration of fluorine that cause a phototoxicological effect on the plant is ___________
a) 0.1μg/m3
b) 0.3μg/m3
c) 0.5μg/m3
d) 1μg/m3

View Answer

Answer: b
Explanation: Fluorine is produced through aluminium or glass industries and it causes a phototoxicological effect on the plant at a concentration of 0.3μg/m3.




6 - Question

Which of the following gas is not colorless?
a) NO
b) O3
c) Pb
d) SO3

View Answer

Answer: a
Explanation: NO is a highly reactive gas which is reddish brown in color, whereas O3, Pb and SO3 are colorless gas.




7 - Question

The effective height of stack is given by ___________
a) Plume height / Actual height of the stack
b) Plume height * Actual height of the stack
c) Plume height – Actual height of the stack
d) Plume height + Actual height of the stack

View Answer

Answer: d
Explanation: Effective height of the stack, H = h1 + h2 where, h1 is the plume height and h2 is the actual height of stack.




8 - Question

 The chimney is emitting particulate matter. Which of the following is the correct expression of the height of the chimney? Here ‘Kp’ represents the emission of particulate matter.
a) HC = 74 Kp0.27
b) HC = 14 Kp0.27
c) HC = 14 Kp0.47
d) HC = 74 Kp0.33

View Answer

Answer: a
Explanation: Height of the chimney HC = 74 Kp0.27 where HC is in metre and ‘Kp’ is in tonnes per hours.




9 - Question

What is the minimum height of the chimney in a thermal power plant of capacity 350MW?
a) 100m
b) 220m
c) 380m
d) 60m

View Answer

Answer: b
Explanation: As the capacity of the thermal plant lies between 200MW and 500MW, the minimum height height of the chimney is 220m.




10 - Question

Which of the following is the correct expression of the height of chimney emitting sulfur dioxide?
a) HC = 74 Kp0.27
b) HC = 14 Kp0.33
c) HC = 14 Kp0.47
d) HC = 74 Kp0.33

View Answer

Answer: b
Explanation: Height of the chimney, HC = 14 Kp0.33 when the chimney is emitting sulfur dioxide. Here, the unit of ‘Kp’ is in kg/hour and HC is in metre.

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