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Chemical Engineering :: Fluid Mechanics

  1. Pick out the wrong statement.

  2. A.

     Surface tension of a liquid is because of the difference in magnitude of adhesive & cohesive forces

    B.

     A hydrometer used for the determination of specific gravities of liquids works on the principle of buoyant forces

    C.

     In case of unsteady fluid flow, the velocity at any given point does not change with time

    D.

     Turbulent fluid flow is characterised by the rapid fluctuation of instantaneous pressure & velocity at a point


  3. In parallel pipe problems, the

  4. A.

     Head loss is the same through each pipe

    B.

     Discharge is the same through all the pipes

    C.

     Total head loss is equal to the sum of the head losses through each pipe

    D.

     None of these


  5. In turbulent flow, the

  6. A.

     Fluid particles move in an orderly manner

    B.

     Momentum transfer is on molecular scale only

    C.

     Shear stress is caused more effectively by cohesion than momentum transfer

    D.

     Shear stresses are generally larger than in a similar laminar flow


  7. The boundary layer is that part of a moving fluid, in which the fluid velocity is

  8. A.

     Affected by the fluid flow pressure

    B.

     Constant

    C.

     Affected by the presence of a solid boundary

    D.

     All of the above


  9. A centrifugal pump designed for handling water (μ = 1 cp) will deliver __________ when pumping a thicker oil (μ = 30 cp).

  10. A.

     Less head & capacity

    B.

     More head

    C.

     More capacity

    D.

     Less head & more capacity


  11. Which of the following flow measuring devices is an area meter?

  12. A.

     Venturimeter

    B.

     Orifice meter

    C.

     Anemometer

    D.

     Rotameter


  13. For a given fluid flow rate, which of the following incurs maximum head loss?

  14. A.

     Orifice meter

    B.

     Venturimeter

    C.

     Flow nozzle

    D.

     All of the above


  15. A rotameter through which air at room temperature and atmospheric pressure is flowing gives a certain reading for a flow rate of 100 cc/sec. If helium (molecular weight 4) is used and rotameter shows the same reading, the flow rate (cc/sec) is

  16. A.

     26

    B.

     42

    C.

     269

    D.

     325


  17. A weir is used to measure the large water discharge rate from a river or from an open channel. A weir is not of __________ shape.

  18. A.

     Circular

    B.

     Rectangular

    C.

     Triangular

    D.

     Trapezoidal


  19. A stream tube is that, which has __________ cross-section entirely bounded by stream lines.

  20. A.

     A circular

    B.

     Any convenient

    C.

     A small

    D.

     A large