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Chemical Engineering :: Heat Transfer

  1. Crystallisation of solids from a homogeneous solution is a/an __________ process.

  2. A.
    exothermic
    B.
    mildly endothermic
    C.
    highly endothermic
    D.
    none of these

  3. A multiple effect evaporator has a capacity to process 4000 kg of solid caustic soda per day, when it is concentrating from 10% to 25% solids. The water evaporated in kg per day is

  4. A.
    6000
    B.
    24000
    C.
    60000
    D.
    48000

  5. Value of Prandtl number for water ranges from

  6. A.
    l to 2
    B.
    5 to 10
    C.
    100 to 500
    D.
    1000 to 2000

  7. Heat transfer in the laminar sublayer in case of a liquid flowing through a pipe, is mostly by

  8. A.
    eddies current
    B.
    conduction
    C.
    convection
    D.
    none of these

  9. Among liquids, water has a comparatively high value of thermal conductivity, due to its

  10. A.
    low density
    B.
    high viscosity
    C.
    partial ionisation
    D.
    dense structure

  11. Reynold's analogy states that (where, St = Stanton number f = friction factor)

  12. A.
    B.
    C.
    St = 4f
    D.
    St = f1/2

  13. For evaporation of viscous solution in a multiple effect evaporator, the prefered feeding scheme is

  14. A.
    forward
    B.
    backward
    C.
    parallel
    D.
    none of these

  15. The film thickness for laminar film condensation on vertical surface __________ from top to bottom.

  16. A.
    cummulatively increases
    B.
    cummulatively decreases
    C.
    remains constant
    D.
    and the surface conductance increase

  17. In case of a multipass shell and tube heat exchanger, providing a baffle on the shell side __________ the heat transfer rate.

  18. A.
    increases
    B.
    decreases
    C.
    does not affect
    D.
    may increase or decrease, depends on the type of baffle

  19. The local surface conductance for laminar film condensation on vertical surface is (where, t = film thickness)

  20. A.
    t
    B.
    ∝ 1/t
    C.
    t
    D.
    independent of 't'