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Chemical Engineering :: Fluid Mechanics

  1. The resistance wire used in a hot wire anemometer for conducting electrical current is made of

  2. A.

     Copper

    B.

     Tungsten

    C.

     Chromium

    D.

     Aluminium


  3. Liquid delivery by centrifugal pump starts, only when the head developed by it is equal to the __________ head.

  4. A.

     Manometric

    B.

     Total

    C.

     Static

    D.

     Friction


  5. The Mach number for hypersonic flow of compressible fluid is

  6. A.

     1

    B.

     > 1

    C.

     > 4

    D.

     < 2


  7. Which of the following is used for very accurate measurement of flow of gas at low velocity?

  8. A.

     Pitot tube

    B.

     Rotameter

    C.

     Segmental orificemeter

    D.

     Hot wire annemometer


  9. For laminar flow through a closed conduit

  10. A.

     Vmax = 2Vav

    B.

     Vmax = Vav

    C.

     Vmax = 1.5Vav

    D.

     Vmax = 0.5Vav


  11. Shear stress in a fluid flowing in a round pipe

  12. A.

     Varies parabolically across the cross-section

    B.

     Remains constant over the cross-section

    C.

     Is zero at the centre and varies linearly with the radius

    D.

     Is zero at the wall and increases linearly to the centre


  13. Select the wrong statement pertaining to flow of an incompressible fluid through a venturimeter.

  14. A.

     For frictionless flow, the fluid pressure entering the venturi meter will be exactly equal to that leaving the venturimeter

    B.

     Discharge of fluid through a venturimeter depends upon the gage difference irrespective of the orientation of venturimeter

    C.

     Venturimeter occupies less space than an orificemeter

    D.

     Venturimeter incurs less power loss compared to an equivalent orificemeter


  15. Two fluids are flowing through two similar pipes of the same diameter. The Reynold's number is same. For the same flow rate if the viscosity of a fluid is reduced to half the value of the first fluid, the pressure drop will

  16. A.

     Increase

    B.

     Decrease

    C.

     Remain unchanged

    D.

     Data insufficient to predict relative pressure drop


  17. A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below :
    Δ P/L = 375 x 10³ VOM + 10.94 x 10⁶ V²OM (SI units)
    If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is

  18. A.

     12 mm/s

    B.

     16 mm/s

    C.

     24 mm/s

    D.

     28 mm/s


  19. A venturimeter can not be used for the direct measurement of

  20. A.

     Datum difference in the stretch of pipeflow

    B.

     Pressure difference in the flow throughpipeline

    C.

     Friction loss in pipe flow

    D.

     All of the above