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MCQs

Total Questions : 1556 | Page 7 of 156 pages
Question 61. The spacing of bars of perforations of fine screens used for the treatment of sewage, is
  1.    2 to 3 mm
  2.    3 to 5 mm
  3.    5 to 8 mm
  4.    8 to 10 mm
 Discuss Question
Answer: Option A. -> 2 to 3 mm
Question 62. The spacing of bars for perforations in coarse screens used for the treatment of sewage, is
  1.    20 mm
  2.    30 mm
  3.    40 mm
  4.    50 mm
 Discuss Question
Answer: Option D. -> 50 mm
Question 63. Before discharging the foul sewage into rivers, it is generally treated by
  1.    Screening
  2.    Sedimentation
  3.    Oxidation
  4.    All the above
 Discuss Question
Answer: Option D. -> All the above
Question 64. The following is the physical characteristic of sewage
  1.    Turbidity
  2.    Colour
  3.    Odour
  4.    All the above
 Discuss Question
Answer: Option D. -> All the above
Question 65. If the flame of a miner's safety lamp in the upper layers of the sewer forms an explosive, the sewer certainly contains
  1.    Hydrogen sulphide
  2.    Carbon dioxide
  3.    Methane
  4.    Oxygen
 Discuss Question
Answer: Option C. -> Methane
Question 66. If a paper moistened with lead acetate for five minutes when placed in manhole turns black. The sewer certainly contains
  1.    Hydrogen sulphide
  2.    Carbon dioxide
  3.    Methane
  4.    Oxygen
 Discuss Question
Answer: Option A. -> Hydrogen sulphide
Question 67. If the flame of a miner’s safety lamp in a manhole extinguishes within 5 minutes, the sewer certainly contains
  1.    Hydrogen sulphide
  2.    Carbon dioxide
  3.    Methane
  4.    Oxygen
 Discuss Question
Answer: Option B. -> Carbon dioxide
Question 68. The pressure exerted by
  1.    The sewage when running full from inside, is called internal pressure
  2.    The internal pressure if any, causes tensile stress in the pipe material
  3.    Pressure sewers are designed to be safe in tension
  4.    All the above
 Discuss Question
Answer: Option D. -> All the above
Question 69. Inter-distance between ventilation columns in a sewer line is kept
  1.    25 to 50 m
  2.    50 m to 100 m
  3.    100 m to 150 m
  4.    150 m to 300 m
 Discuss Question
Answer: Option D. -> 150 m to 300 m
Question 70. The factor responsible for purification of sewage in river is
  1.    Hydrology
  2.    Dissolved oxygen in water
  3.    Temperature
  4.    All the above
 Discuss Question
Answer: Option D. -> All the above

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