Engineering Questions with Answers - Multiple Choice Questions

Environmental Engineering MCQ – Pollution Zones in River

1 - Question

The pollution zones in the river are divided into how many types?
a) 3
b) 4
c) 6
d) 8

View Answer

Answer: b
Explanation: There are 4 types of pollution zones in the river, namely zone of degradation, zone of active decomposition, zone of recovery and zone of clear water.




2 - Question

In which pollution zone of the river, growth of algae reappear?
a) Zone of degradation
b) Zone of recovery
c) Zone of active decomposition
d) Zone of clean water

View Answer

Answer: b
Explanation: The growth of algae reappear in the zone of recovery.The growth of fungi decreases.




3 - Question

In which pollution zone of the river, the dissolved oxygen reduced to 0?
a) Zone of degradation
b) Zone of recovery
c) Zone of clean water
d) Zone of active decomposition

View Answer

Answer: d
Explanation: The dissolved oxygen, reduced to 0 in the zone of active decomposition. The water is highly polluted in this zone.




4 - Question

Which is the third zone of pollution in the river?
a) Zone of recovery
b) Zone of degradation
c) Zone of clean water
d) Zone of active decomposition

View Answer

Answer: a
Explanation: The zone of recovery is the third zone of pollution in the river where river tries to recover the polluted water through the self purification process.




5 - Question

In which pollution zone of the river, water retains its original dissolved oxygen concentration?
a) Zone of degradation
b) Zone of recovery
c) Zone of active decomposition
d) Zone of clean water

View Answer

Answer: d
Explanation: The water retains its original dissolved oxygen concentration in the zone of clean water. It has a clear appearance.




6 - Question

The fishes were present in the river, but algaes were not able to survive. What is the zone of pollution of the river?
a) Zone of recovery
b) Zone of degradation
c) Zone of clean water
d) Zone of active decomposition

View Answer

Answer: b
Explanation: It is the zone of degradation as dissolved oxygen has reduced to 40%. The fishes will die when dissolved oxygen is less than 4ppm.




7 - Question

In which pollution zone of the river, the concentration of D.O reduced to 40%?
a) Zone of degradation
b) Zone of recovery
c) Zone of active decomposition
d) Zone of clean water

View Answer

Answer: c
Explanation: In the zone of active decomposition, the concentration of D.O reduced to 40%. It is the second zone of pollution in the river.

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