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Civil Engineering :: Hydraulics

  1. Flow in pipes is laminar if Reynold number is

  2. A.

    less than 2100

    B.

    more than 3000

    C.
    between 2100 and 3000
    D.

    none of these.


  3. The terminal velocity (v) of a sphere of radius r and specific weight W, which travels vertically downwards in a liquid of viscosity μ and specific weight W, is

  4. A.

    v = \( \frac { 2r^3 } {9\mu } \)(Ws- W)

    B.

    v = \( \frac { 2r^2 } {9\mu } \)(Ws- W)

    C.

    V = 9 \( \frac { r^2 } {2\mu } \)(Ws- W)

    D.

    V = \( \frac { 3r^2 } {3\mu } \)(Ws- W)


  5.  

    In flow, the liquid particles may possess

  6. A.

    potential energy

    B.

    kinetic energy

    C.

    pressure energy

    D.

    all the above.


  7. Euler's equation for the motion of liquids assumes that

  8. A.

    fluid is viscous

    B.

    fluid is homogeneous and incompressible

    C.

    velocity of flow is non-uniform over the section

    D.

    flow is unsteady along the stream line.


  9. The height of water level in a tank above the centre of a circular hole 2.5 cm in diameter is 50 m. The velocity of water flowing through the hole, is

  10. A.

    31.1 m/sec

    B.

    31.2 m/sec

    C.

    31.3 m/sec

    D.

    31.4 m/sec.


  11. A steady uniform flow is through

  12. A.

    a long pipe at decreasing rate

    B.

    a long pipe at constant rate

    C.

    an expanding tube at constant rate

    D.

    an expanding tube at increasing rate

    E.
    a long pipe at increasing rate.

  13. Cavitation is caused by

  14. A.

    Low pressure

    B.

    High pressure

    C.

    Low velocity

    D.

    High velocity

    E.

    None of these.


  15. Mach number is the ratio of inertia force to

  16. A.
    viscosity
    B.

    surface tension

    C.

    gravitational force

    D.

    elasticity.


  17. Hydraulic gradient is equal to difference in water surfaces

  18. A.

    \(\frac { \text{difference in water surface} } {\text{total length of the channel} } \)

    B.

    \(\frac { \text{head loss due to friction} } {\text{total length of the channel} } \)

    C.

    \(\frac { \text{wetted perimeter} } {\text{total length of the channel} } \)

    D.

    \(\frac { \text{area of the cross -section} } {\text{total length of the channel} } \)


  19. The main assumption of Bernoulli's equation is :

  20. A.

    The velocity of energy of liquid particle, across any cross-section of a pipe is uniform

    B.

    No external force except the gravity acts on the liquid

    C.

    There is no loss of energy of the liquid while flowing

    D.

    All the above.