Sewer Construction MCQ and Sewer Design MCQ

1. What is the recommended diameter of a domestic sewer pipe laid at gradient 1 in 100?

  1. 100 mm
  2. 50 mm
  3. 175 mm
  4. 150 mm
Answer
Answer. d

2. If the slopes of two sewers A and B of same size are 1 in 100 and 1 in 400 respectively, the ratio of velocity of flow in the two sewers A and B will be

  1. 1
  2. 0.5
  3. 22/3
  4. 2
Answer
Answer. d

3. If D is the diameter of upper circular portion, the overall depth of New Egg shaped sewer section is

  1. 1.350 D
  2. 1.250 D
  3. 1.625 D
  4. 1.425 D
Answer
Answer. c

4. The minimum diameter for public sewer in hilly areas where steep slopes are prevalent is

  1. 150
  2. 3000
  3. 20
  4. 100
Answer
Answer. d

5. For taking sewer line below road/canal/railway line, following type or sewer appurtenances should be provided

  1. Storm water relief work
  2. Siphon spillways
  3. Jumping weir
  4. Inverted syphon
Answer
Answer. d

6. The best sewer material to resist hydrogen sulphide corrosion is

  1. glazed stone ware
  2. reinforced cement concrete
  3. asbestos cement
  4. none of these
Answer
Answer. a

7. The diameter of a RCC sewer pipe is 300mm. The gradient required to generate self cleansing velocity would be of the order of

  1. 1 in 190
  2. 1 in 100
  3. 1 in 920
  4. 1 in 220
Answer
Answer. d

8. Laying of sewers is usually done with the help of

  1. a theodolite
  2. a compass
  3. a plane table
  4. sight rails and boning rods
Answer
Answer. d

9. Sewer pipes are made of

  1. stone ware
  2. earthen ware
  3. terracotta
  4. refractory ware
Answer
Answer. a

10. Crown corrosion in sewer is caused due to the presence of

  1. Bromide
  2. Nitrate
  3. Chloride
  4. Sulphate
Answer
Answer. d

11. In stoneware pipe glazing is made for

  1. waterproofing
  2. softening
  3. hardening
  4. none of the above
Answer
Answer. a

12. Corrosion in concrete sewer is caused by

  1. DO
  2. H2S
  3. Chlorine
  4. Nitrogen
Answer
Answer. b

13. The hydraulic mean depth of a circular sewer running full is equal to

  1. d/4
  2. d/2
  3. d/8
  4. d/6
Answer
Answer. a