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Civil Engineering :: Waste Water Engineering

  1. The effluent of a septic tank is

  2. A.

     Fit for discharge into any open drain

    B.

     Foul and contains dissolved and suspended solids

    C.

     As good as that from a complete treatment

    D.

     None of these


  3. 5 days-biochemical oxygen demand (BOD5) is taken at a temperature of

  4. A.

     0°C

    B.

     15°C

    C.

     20°C

    D.

     25°C


  5. The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope

  6. A.

     1 in 5

    B.

     1 in 10

    C.

     1 in 15

    D.

     1 in 20


  7. Drop manholes are the manholes

  8. A.

     Without entry ladders

    B.

     Without manhole covers

    C.

     With depths more than 3.5 m

    D.

     Having drains at different levels


  9. For laying a sewer line in a trench of 2 m width, an offset line is marked on the ground parallel to the given centre line at a distance of

  10. A.

     100 cm

    B.

     120 cm

    C.

     140 cm

    D.

     160 cm


  11. The rainfall at any place may be determined by

  12. A.

     Its intensity

    B.

     Its direction

    C.

     Its frequency

    D.

     All the above


  13. The clarigesters are

  14. A.

     Circular septic tanks

    B.

     Rectangular septic tanks

    C.

     Circular Imhoff double tanks with bottom hoppers

    D.

     Circular Imhoff double storey tanks without bottom hoppers


  15. If the grit in grit chambers is 4.5 million litres per day, its cleaning is done

  16. A.

     Manually

    B.

     Mechanically

    C.

     Hydraulically

    D.

     Electrically


  17. In R.C. sewer pipes, the percentage longitudinal reinforcement to the cross-sectional area of concrete is kept

  18. A.

     10.0

    B.

     5.0

    C.

     2.0

    D.

     0.25


  19. A manhole is classified as shallow if its depth is between

  20. A.

     0.4 to 0.5 m

    B.

     0.5 to 0.7 m

    C.

     0.7 to 0.9 m

    D.

     0.9 to 1.20 m