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Chemical Engineering :: Fluid Mechanics

  1. In case of laminar flow of fluid through a circular pipe, the

  2. A.
    shear stress over the cross-section is proportional to the distance from the surface of the pipe.
    B.
    surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder.
    C.
    velocity profile varies hyperbolically and the shear stress remains constant over the cross-section.
    D.
    average flow occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius).

  3. Which of the following facilitates close control of flow of fluids ?

  4. A.
    Gate valve
    B.
    Globe valve
    C.
    Butterfly valve
    D.
    Check valve

  5. Fanning friction factor equation applies to the __________ fluid flow.

  6. A.
    non-isothermal condition of
    B.
    compressible
    C.
    both (a) and (b)
    D.
    neither (a) nor (b)

  7. Stoke's equation is valid in the Reynolds number range

  8. A.
    0.01 to 0.1
    B.
    0.1 to 2
    C.
    2 to 10
    D.
    10 to 100

  9. When a fluid flows over a solid surface, the

  10. A.
    velocity is uniform at any cross-section.
    B.
    velocity gradient is zero at the solid surface.
    C.
    resistance between the surface & the fluid is lesser as compared to that between the fluid layers themselves.
    D.
    velocity is not zero at the solid surface.

  11. Pick out the wrong statement about cavitation.

  12. A.
    Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation.
    B.
    Cavitation may be caused due to boiling of liquid by decreasing the pressure resulting in formation & collapse of vapor cavities.
    C.
    Cavitation begins at higher static pressure and lower velocity in larger diameter pipelines resulting in audible noise.
    D.
    Large scale cavitation can not damage pipeline, restrict fluid flow and damage steam turbine blades.

  13. The maximum delivery pressure of a reciprocating compressor may be about __________ kg/cm2.

  14. A.
    1000
    B.
    2000
    C.
    3000
    D.
    4000

  15. The velocity for subsonic flow in a pipeline

  16. A.
    increases in the downstream direction.
    B.
    is constant.
    C.
    decreases in the downstream direction.
    D.
    is independent of the area of flow.

  17. Permanent pressure loss in a well designed venturimeter is about __________ percent of the venturi differential.

  18. A.
    1
    B.
    10
    C.
    30
    D.
    50

  19. The ratio of pressure forces to inertial forces is called the __________ number.

  20. A.
    Froude
    B.
    Euler
    C.
    Reynold
    D.
    Mach