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Chemical Engineering :: Fluid Mechanics

  1. Pascal's law is valid, only when the fluid is

  2. A.

     Frictionless and at rest

    B.

     At rest

    C.

     At rest and when the frictionless fluid is in motion

    D.

     None of these


  3. Friction factor for a hydraulically smooth pipe at NRe = 2100 is f₁. If the pipe is further smoothened (i.e., roughness is reduced), the friction factor at the same value of NRe, will

  4. A.

     Increase

    B.

     Decrease

    C.

     Remain unchanged

    D.

     Increase or decrease depending on the pipe material


  5. Two piping system are said to be equivalent, when the __________ are same.

  6. A.

     Fluid flow rate & friction loss

    B.

     Length & friction factor

    C.

     Diameter & friction factor

    D.

     Length & diameter


  7. The pressure at a point in a fluid is not the same in all directions, when the fluid is viscous and

  8. A.

     Moving

    B.

     Static

    C.

     Cold

    D.

     Hot


  9. In fluid flow, the stagnation point is defined as a point, where the __________ is zero.

  10. A.

     Flow velocity

    B.

     Pressure

    C.

     Total energy

    D.

     All of the above


  11. A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke's law. A particle B with diameter 20 microns settling in the same oil will have a settling velocity

  12. A.

     Same as that of A

    B.

     One fourth as that of A

    C.

     Twice as that of A

    D.

     Four times as that of A


  13. A rectangular surface 3' x 4', has the lower 3 edge horizontal and 6' below a free oil surface (sp. gr. 0.8). The surface inclination is 300 with the horizontal. The force on one side of the surface is(where, y = specific weight of water)

  14. A.

     39.6y

    B.

     48y

    C.

     49.2y

    D.

     58y


  15. Dimension of surface tension is(where, F = force, L = length)

  16. A.

     FL⁻¹

    B.

     F⁻¹ . L

    C.

     F.L⁻²

    D.

     F⁻² . L


  17. In fluid flow, cavitation is caused, if the

  18. A.

     Fluid velocity decreases to zero

    B.

     Total energy decreases

    C.

     Both A and B

    D.

     Flow pressure approaches its vapor pressure at the prevailing temperature


  19. When the momentum of one fluid is used for moving another fluid, such a device is called a/an

  20. A.

     Jet pump

    B.

     Blower

    C.

     Acid egg

    D.

     None of these