This set of Waste Water Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Sewer Appurtenances”.
1. What are the structures that are constructed at suitable intervals along the sewerage system called?
b) Catch basins
d) Sewer appurtenances
Explanation: Sewer appurtenances are the structures that are constructed at suitable intervals along the sewerage system. These include many structures such as manholes, drop manholes, lamp holes, clean-outs, catch basins, etc.
2. A masonry or R.C.C. chamber constructed at suitable intervals along the sewer lines, for providing access into them is called _________
a) Inverted siphons
c) Flushing tanks
Explanation: The manhole helps in inspection, cleaning and maintenance of sewer. These are provided at every junction, change of diameter or change of gradient of the sewer.
3. What is the spacing of manholes for pipe diameter of greater than 2 m?
a) 90-150 m
b) 150-200 m
c) 300 m
d) 45-90 m
Explanation: For smaller sewers that are of pipe diameter less than 0.9 m, the spacing given in between manholes is 45 m. In case of pipe diameter of sewers greater than 2 m, the spacing is 300 m.
4. What are the manholes having a depth greater than 1.5 m called?
a) Normal manholes
b) Deep manholes
c) Shallow manholes
d) Straight manholes
Explanation: The manholes having a depth of 0.7-0.9 m are called shallow manholes. The manholes having a depth of 1.5 m are called normal manholes. The manholes having depth greater than 1.5 m are called deep manholes.
5. What is a sewer that runs full under gravity, flow at a pressure above the atmosphere in the sewer called?
a) Flushing manhole
b) Inverted siphon
d) Curb inlet
Explanation: Inverted siphons are used to pass on obstacles such as buried pipes, subways, etc. This terminology ‘siphon’ is misnomer as there is no siphon action in the depressed sewer.
6. What is the facility provided to stop the entry of heavy debris present in the storm water into the sewers called?
a) Curb inlet
b) Gutter inlet
c) Catch basin
Explanation: Clean-out is a pipe which is connected to the underground sewer. Curb inlets are vertical opening in the road curbs through which stormwater flow enters the stormwater drains. Gutter inlets are horizontal openings in the gutter which is covered by one or more grating through which stormwater is admitted.
7. Lamp hole is an opening or hole constructed in a sewer for purpose of lowering a lamp inside it.
Explanation: Lamp hole consists of stoneware or concrete pipe, which is connected to the sewer line through a T-junction. If the sewer length is unobstructed, the light of a lamp will be seen. It is constructed when the construction of manhole is difficult.
8. The lamp hole cannot be used for the flushing of sewers.
Explanation: Lamp hole can also be used for flushing the sewers. The perforated top cover will help in ventilating the sewer. Such a lamp hole is known as the fresh air inlet. In present practice as far as possible the use of lamp hole is avoided.
9. What is the arrangement for diverting excess sewage from the combined sewer called?
a) Siphon spillway
b) Siphon gateway
c) Leaping weir
d) Intercepting sewer
Explanation: The overflow channel is connected to the combined sewer through the siphon. At the crest level of siphon an air pipe is provided to activate the siphon when water will reach in the combined sewer at a stipulated level and is called siphon spillway.
10. What are the internal dimensions for a sewer of depth less than 0.9 m?
a) 1.5 m
b) 1.8 m
c) 0.9*0.8 m
d) 1.2 m
Explanation: The internal dimension for a sewer of depth less than 0.9 m is 0.9 m * 0.8 m. The internal dimension for a sewer for depth between 0.9 m to 2.5 m is 1.2 m* 0.9 m, 1.2 m diameter for circular.
Sanfoundry Global Education & Learning Series – Waste Water Engineering.
To practice all areas of Waste Water Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.