Environmental Engineering Multiple Choice Questions on “Types of Plumes”.
1. Coning plume occurs under which conditions?
a) Super adiabatic
b) Sub adiabatic
c) Neutral
d) Inversion
Answer: b
Clarification: Coning occurs under sub adiabatic conditions. The plume is of conical shaped.
2. In which of the following plumes, stable condition prevails?
a) Lofting
b) Fanning
c) Neutral
d) Fumigating
Answer: b
Clarification: The stability prevails in the Fanning plume. It occurs during inversion conditions.
3. The upward vertical rise prevails in which of the following plume?
a) Trapping
b) Fanning
c) Looping
d) Neutral
Answer: d
Clarification: In Neutral plume, the Environmental lapse rate is equal to the Adiabatic lapse rate.
4. Which of the following plume is worst for the dispersion of pollutants?
a) Trapping
b) Fanning
c) Neutral
d) Fumigating
Answer: d
Clarification: In Fumigating plume, the pollutants come down near the ground due to turbulence instead of escaping above the stack. This makes it the most dangerous plume.
5. In which of the following plumes, unstable condition prevails?
a) Trapping
b) Fanning
c) Looping
d) Neutral
Answer: c
Clarification: Rapid dispersion of pollutants takes place under Looping plume. It occurs under super adiabatic conditions.
6. Which of the following are contradictory plume?
a) Lofting and fumigating
b) Looping and coning
c) Neutral and lofting
d) Fumigating and trapping
Answer: a
Clarification: In Lofting plume, the super adiabatic lapse rate occurs above the stack, whereas, in Fumigating plume, it occurs below the stack.
7. The maximum efficiency of the electrostatic precipitator is ___________
a) 95%
b) 80%
c) 99%
d) 100%
Answer: c
Clarification: The efficiency of electrostatic precipitator lies between 95% to 99%. They are used in thermal power plants.
8. The minimum particle size removes by the gravitational chamber is ___________
a) >50μm
b) >10μm
c) >25μm
d) >0.5μm
Answer: a
Clarification: The minimum particle size removes by the gravitational settling chamber is >50μm and its efficiency is less than 50%.