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Civil Engineering :: Waste Water Engineering

  1. In circular sewers if depth of flow is 0.2 times the full depth, the nominal gradient,

  2. A.

     Is only provided

    B.

     Is doubled

    C.

     Is trebled

    D.

     Is not enough


  3. The liquid wastes from kitchens, bath rooms and wash basins, is not called

  4. A.

     Liquid waste

    B.

     Sullage

    C.

     Sewage

    D.

     None of these


  5. If the diameter of a sewer is 100 mm, the gradient required for generating self cleansing velocity is

  6. A.

     1 in 60

    B.

     1 in 100

    C.

     1 in 120

    D.

     None of these


  7. Self-cleansing velocity is

  8. A.

     Velocity at dry weather flow

    B.

     Velocity of water at flushing

    C.

     Velocity at which no accumulation remains in the drains

    D.

     Velocity of water in a pressure filter


  9. In a city the ratio of the drainage to sewage is 20, the percentage discharge passing through non-monsoon periods, is

  10. A.

     5

    B.

     10

    C.

     15

    D.

     20


  11. For design purposes, the normal rate of infiltration of ground water into the sewer, is

  12. A.

     500 litres/km/cm

    B.

     1000 litres/km/cm

    C.

     1500 litres/km/cm

    D.

     2000 litres/km/cm


  13. If the peak discharge of a storm water drain (S.W. Drain) is expected to exceed 150 cumecs, the free board to be provided, is

  14. A.

     100 cm

    B.

     90 cm

    C.

     80 cm

    D.

     50 cm


  15. In 1000 kg of sewage, the total solids approximate

  16. A.

     0.5 to 1.0 kg

    B.

     1 kg to 2.0 kg

    C.

     5 kg to 7.5 kg

    D.

     7.5 kg to 10 kg


  17. Pick up the incorrect statement from the following:

  18. A.

     The process of decomposing the organic matter under controlled anaerobic conditions, is called sludge digestion

    B.

     Sludge digestion is carried out in sludge tank

    C.

     The gases produced in sludge digestion process, contain 75% carbon dioxide

    D.

     The gases produced in sludge digestion process, contain 75% methane


  19. Pick up the correct statement from the following:

  20. A.

     Turbidity is more in strong sewage

    B.

     The black colour indicates septic sewage

    C.

     The sewage omits offensive odours after four hours

    D.

     All the above