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Civil Engineering :: Water Supply Engineering

  1. The most commonly used chemical for dechlorination of water, is

  2. A.
    sodium thiosulphate
    B.
    sodium bisulphate
    C.
    sodium sulphite
    D.
    sulphur-dioxide
    E.
    all the above.

  3. The prescribed hardness limit of potable water ranges between

  4. A.
    50 to 75 P.P.M.
    B.
    75 to 115 P.P.M.
    C.
    100 to 150 P.P.M.
    D.
    150 to 200 P.P.M.
    E.
    none of these.

  5. For centrifugal pumps

  6. A.
    initial cost is low
    B.
    limited space is required
    C.
    the discharge obtained is steady and non-pulsating
    D.
    all the above.

  7. The cast iron pipes for water supply system are used for

  8. A.
    durability
    B.
    strength
    C.
    easy connection
    D.
    low maintenance cost
    E.
    all the above.

  9. For plain chlorination of water, the quantity of chlorine used, is

  10. A.
    0.1 mg/litre
    B.
    0.2 mg/litre
    C.
    0.3 mg/litre
    D.
    0.4 mg/litre
    E.
    0.5 mg/litre.

  11. For estimating the run off of catchments, the mean value of the constant 'K' in the Khosla's formula Qy = Py - K (1.8 Ty + 32) is

  12. A.
    1.21
    B.
    1.23
    C.
    1.25
    D.
    1.27
    E.
    1.31

  13. Service connections to consumers houses, are generally provided with

  14. A.
    copper pipes
    B.
    hume pipes
    C.
    galvanised iron pipes
    D.
    P.V.C. pipes
    E.
    none of these.

  15. Sluice valves are fitted in a distribution system

  16. A.
    along straight length of pipes at suitable intervals
    B.
    at the junctions of the pipes
    C.
    at the branching off points of sub-mains
    D.
    all the above.

  17. The detention period for plain sedimentation water tanks, is usually

  18. A.
    4 to 8 hours
    B.
    8 to 16 hours
    C.
    16 to 24 hours
    D.
    24 to 36 hours.

  19. The maximum permitted loss of head in a rapid sand filter, is

  20. A.
    1 m
    B.
    2 m
    C.
    3 m
    D.
    4 m
    E.
    5 m.