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Civil Engineering :: Hydraulics

  1. If a1 and a2 are the cross-sectional areas of a tank and orifice, h the height of water level in tank above the centre of the orifice, the velocity of approach is given by

  2. A.

    v = \(\sqrt[]\frac { 2gh } { 1-a2^2/a1} )\)

    B.

    v = \(\sqrt{}1-\frac { \partial2^2 } {\partial1^2 } \)

    C.

    v=\(\sqrt[]\frac { 2gh } { 1-\partial1^2/a2^2} )\)

    D.

     v= \(\sqrt[]\frac { 2gh } { 1-\partial1^1/a1^2} )\)


  3. The hydrostatic force acts through

  4. A.

    centre of pressure

    B.

    centre of top edge

    C.
    centre of bottom edge
    D.
    metacentre.

  5.  

    In an inclined position, a venturimeter records

  6. A.

    more reading

    B.

    less reading

    C.

    same reading

    D.

    none of these.


  7. If E1 and E2 are the specific energies at the start of back water curve and at the maximum rise of water respectively and ib and ie are the head slope and the energy line slope respectively, the length of back water (L) is given by

  8. A.

    L = \(\frac { E2+E1 } { ib-ie } \)

    B.

    L = \(\frac { E2-E1 } { ib-ie } \)

    C.

     L = \(\frac { E2-E1 } { ib+ie } \)

    D.

    None of these.


  9. The velocity of flow at the critical depth (hc) is called critical velocity (Vc) which is equal to

  10. A.

     Vc = g x hc

    B.

    \(\sqrt{g*hc}\)

    C.

    \(3\sqrt{g*hc}\)

    D.

    None of these.


  11.  

    In a short cylindercial external mouthpiece, the venacontracta occurs at a distance from the outlet of orifice equal to

  12. A.

    diameter of the orifice

    B.

    one-fourth the diameter of the orifice

    C.

    one-third the diameter of the orifice

    D.

    two-third the diameter of the orifice


  13.  

    If the pressure at the inlet of a pipe is 90 kg/cm2 and pressure drop over the pipe line is 10 kg/cm2, the efficiency of transmission, is

  14. A.
    66.6%
    B.

    77.7%

    C.

    55.5%

    D.

    88.8%.


  15. Pick up the incorrect statement from to following regarding triangular notch :

  16. A.

    For measuring low discharge, it gives more accurate result

    B.

    Only one reading (i.e. H) is required for computation of discharge

    C.

    Ventilation is necessary

    D.

    None of these.


  17. The flow in a channel is said to be non-uniform, if

  18. A.

    free water surface of an open channel is not parallel to the bed of channel

    B.

    head needed to overcome frictional reistance is less than the drop in elevation of channel bed

    C.

    head needed to overcome frictional resistance is more than the drop in elevation of channel bed

    D.
    all the above.

  19. If H is the depth of water retained by a vertical wall, the height of centre of pressure above the bottom is

  20. A.

    \(\frac { H } { 2 } \)

    B.

    \(\frac { H } { 3 } \)

    C.

    \(\frac { 2H } { 3 } \)

    D.

    \(\frac { H } { 5 } \)