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Civil Engineering :: Irrigation

  1. If the straight sides of a triangular section of a lined canal with circular bottom of radius D, make an angle θ with horizontal, the hydraulic mean depth is

  2. A.

    D

    B.

    D/2

    C.

    D/3

    D.

    D/4

    E.

    D/5


  3. If water table is comparatively high, the irrigation canal becomes useless, due to

  4. A.
    large amount of seepage
    B.

    water logging of the cultivated areas

    C.

    uncertain water demand

    D.

    spread of malaria

    E.

    all the above.


  5. A river is said to be of

  6. A.

    aggrading type if it builds up its bed to a certain slope

    B.

    degrading type if it cuts its bed to a certain slope

    C.

    meandering type if it flows in sinuous curve

    D.

    all the above.


  7. A land is said to be water-logged if its soil pores within

  8. A.

    a depth of 40 cm are saturated

    B.

    a depth of 50 cm are saturated

    C.

    root zone of the crops are saturated

    D.

    all the above.


  9. In case of a trapezoidal notch fall

  10. A.

    top width of the notch is kept between 3/4 th of full water depth above the sill of the notch

    B.

    top length of the piers should not be less than their thickness

    C.

    splay up stream from the notch section is 45°

    D.

    splay down stream from the notch section is 22 \( \frac { 1 } { 2 }^0\)

    E.

    all the above.


  11. If D1 and D2 are depths of water upstream and down stream of a hydraulic jump, the loss of head at the jump, is

  12. A.

    \(\frac { (D2-D1)^3 } { D1D2} \)

    B.

    \(\frac { (D2-D1)^3 } { 2D1D2} \)

    C.

    \(\frac { (D2-D1)^3 } { 3D1D2} \)

    D.

    \(\frac { (D2-D1)^3 } { 4D1D2} \)


  13. If Dc is the critical depth, D is the depth of water down stream and HL is the total head loss at the cistern of a vertical fall, the depth x of the cistern below the bed level down stream suggested by Blench, is

  14. A.

    Dc- D +\(\frac { 1 } { 4} \)[HL- \( \frac { 3} { 8} Dc\)]

    B.

    2 Dc - D +\(\frac { 1 } { 4} \)[ HL-\( \frac { 3} { 8} Dc\)]

    C.

    2 Dc - D +\(\frac { 3 } { 8} \) [ Hc - \(\frac { 1 } { 4} \)Dc]

    D.

    3Dc -D +\(\frac { 3 } { 8} \)[ HL -\(\frac { 1 } { 4} \)Dc]


  15. The uplift pressure on the roof of an inverted syphon, is maximum when

  16. A.

    drain in running dry

    B.

    canal is running dry

    C.

    canal is running with F.S.L.

    D.

    drain is running with H.F.L.


  17. In rigid module, the discharge

  18. A.

    is independent of water levels in the distributary and water course

    B.

    depends upon the water level in distributary

    C.
    depends upon the water level in the water course
    D.

    depends upon the water levels of both, i.e. distributary and water course

    E.

    none of these.


  19. The ratio of the rate of change of discharge of an outlet and parent channel, is known as

  20. A.

    efficiency

    B.

    sensitivity

    C.

    flexibility

    D.

    modular limit.