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Chemical Engineering :: Fluid Mechanics

  1. Froude number is the ratio of

  2. A.

     Shear stress to gravitational stress

    B.

     Drag stress to shear stress

    C.

     Inertial stress to shear stress

    D.

     Inertial stress to gravitational stress


  3. Applicability of Bernoulli's equation is limited to a/an __________ fluid, that does not exchange shaft work with the surroundings.

  4. A.

     Incompressible

    B.

     Non-viscous

    C.

     Both A and B

    D.

     Neither A nor B


  5. Disc compensators are provided in large diameter fuel gas carrying pipelines to

  6. A.

     Keep the pipe in proper orientation

    B.

     Make the pipe joint leak-proof

    C.

     Account for contraction/expansion of pipe due to temperature changes of the surroundings

    D.

     Account for the pressure variation side the pipeline


  7. During ageing of fluid carrying pipes, the

  8. A.

     Pipe becomes smoother with use

    B.

     Friction factor increases linearly with time

    C.

     Absolute roughness decreases with time

    D.

     Absolute roughness increases linearly with time


  9. A gas (density = 1.5 kg/m³ , viscosity = 2x 10⁻⁵ kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The pressure drop for another gas, with density of 1.5kg/m³and viscosity of 3 x 10⁻⁵kg/m.s flowing at 3 m/s will be

  10. A.

     8400 Pa/m

    B.

     12600 Pa/m

    C.

     18900 Pa/m

    D.

     16800 Pa/m


  11. Centrifugal pump can't be used to pump

  12. A.

     Molten sodium (used as a coolant in Fast Breeder Reactor)

    B.

     Moderately viscous vegetable oil used in soap industry

    C.

     Thick molten soap at 80°C

    D.

     None of the above


  13. The general relationship between speed N, head H, power P and discharge Q for a centrifugal pump is

  14. A.

     Q∝N : H∝N² : P∝N³

    B.

     Q∝N² : H∝N³ : P∝N

    C.

     Q∝N : H∝N³ : P∝N²

    D.

     Q∝N³ : H∝N : P∝N²


  15. The percentage slip in a reciprocating pump set is given by the % of (where, Q₁ = actual discharge Q₂ = theoretical discharge)

  16. A.

     Q₁/Q₂

    B.

     Q₂/Q₁

    C.

     (Q₂ - Q₁)/Q₁

    D.

     (Q₂ - Q₁)/Q₂


  17. What is the shear rate at the pipe wall, in case of laminar flow of Newtonion fluids in a pipe of diameter 'D' & length 'L' incurring a pressure drop 'Δp' with average velocity 'Vavg'?

  18. A.

     D Δp/8L

    B.

     D Δp/4L

    C.

     8 . Vavg/D

    D.

     4 . Vavg/D


  19. Gear pump

  20. A.

     Is a positive displacement pump

    B.

     Is a centrifugal pump

    C.

     Is a non-positive displacement pump

    D.

     Can be started with delivery valve closed