Engineering Questions with Answers - Multiple Choice Questions
Environmental Engineering MCQ’s – Devices Associated with Sewer
1 - Question
Which of the following is not a sewer appurtenance?
a) Storm regulator
b) Flushing tank
c) Water tank
d) Manholes
View Answer
Answer: c
Explanation: Sewer appurtenance are the structures that are constructed for the efficient performance and maintenance of sewers. The water tank is not a sewer appurtenance.
2 - Question
_____ provides the working space for maintenance and inspection of sewers.
a) Lamp holes
b) Manholes
c) Flushing tanks
d) Working chamber
View Answer
Answer: d
Explanation: Working chamber provides the working space for maintenance and inspection of sewers. It is situated at the lower part of the manhole.
3 - Question
The minimum thickness of the side wall of the manhole is __________
a) 50mm
b) 100mm
c) 225mm
d) 300mm
View Answer
Answer: c
Explanation: The minimum thickness of the side wall of the manhole is 225mm and they are commonly made of bricks.
4 - Question
Which of the following is situated above the working chamber in a deep manhole?
a) Main sewer
b) Access shaft
c) Branch sewer
d) Channel
View Answer
Answer: b
Explanation: The access shaft lies above the working chamber which is just below the manhole cover.
5 - Question
If the depth of excavation is 4m. What is the thickness of the brick wall of manhole?
a) 12cm
b) 16cm
c) 20cm
d) 26cm
View Answer
Answer: d
Explanation: The thickness of brick wall of manhole (in cm) = 10 + 4*depth of excavation (in m) = 10 + 4*4 = 26cm.
6 - Question
Into how many types manholes are classified on the basis of depth of manhole?
a) 3
b) 5
c) 6
d) 7
View Answer
Answer: a
Explanation: Manholes are classified into Shallow, Normal and Deep on the basis of depth of the manhole.
7 - Question
The minimum diameter of the access shaft for a circular manhole is __________
a) 60cm
b) 20cm
c) 30cm
d) 10cm
View Answer
Answer: a
Explanation: Access shaft is the upper portion of manhole whose minimum diameter for a circular manhole is 60cm.
8 - Question
The manhole in which inclined pipe for transfer of sewage from branch to main sewer is __________
a) Deep manhole
b) Ramp
c) Drop manhole
d) Normal manhole
View Answer
Answer: b
Explanation: Ramp has an inclined pipe for the transfer of sewage which is used when the drop is less.
9 - Question
The thickness of the manhole frame is __________
a) 10cm
b) 15cm
c) 20cm
d) 40cm
View Answer
Answer: c
Explanation: The manhole frame is made of cast iron having 10cm width and the thickness is 20cm.
10 - Question
The minimum diameter of the working chamber for a circular manhole is __________
a) 0.8m
b) 0.9m
c) 1m
d) 1.2m
View Answer
Answer: d
Explanation: The working chamber is the lower portion of the manhole having a minimum diameter of 1.2 m.
11 - Question
The manhole in which vertical pipe is used for the transfer of sewage from branch to main sewer is __________
a) Deep manhole
b) Ramp
c) Drop manhole
d) Normal manhole
View Answer
Answer: c
Explanation: Drop manholes are provided with vertical pipe so that the sewage does not fall on the people working at manhole.
12 - Question
Which sewer appurtenance allows lamp in the sewer?
a) Catch basin
b) Drop manhole
c) Lamp hole
d) Storm regulators
View Answer
Answer: c
Explanation: The lamp hole is acting as an inspection device where lamps are inserted. It is used when the construction of manhole is difficult.
13 - Question
Which sewer appurtenance is used for removing rainwater from the roads?
a) Catch basin
b) Gullies
c) Lamp hole
d) Storm regulators
View Answer
Answer: b
Explanation: Gullies are placed along the roadside at an interval of 30-60m to remove the rainwater from the road
14 - Question
_______ removes oil and grease from the sewage.
a) Catch basin
b) Gullies
c) Grease and oil traps
d) Storm regulators
View Answer
Answer: c
Explanation: The oil and grease sticks to the sides of the sewer and reduces the sewer capacity. So, it is essential to remove oil and grease, which can be done by the device called as Grease and oil traps.
15 - Question
Which device is used to prevent the clogging of sewer pipes?
a) Flushing tank
b) Drop manhole
c) Lamp hole
d) Storm regulators
View Answer
Answer: a
Explanation: Flushing tank is used to flush and clean the sewer to prevent it from clogging. This is done either by automatic flushing tank or by hand operated flushing tank.