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Chemical Engineering :: Heat Transfer

  1. Kg of liquid evaporated per hour in an evaporator is defined as its

  2. A.
    capacity
    B.
    economy
    C.
    steam load
    D.
    none of these

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  3. Pick out the correct statement.

  4. A.
    1 kcal/hr.m.°C is equal to 1 BTU/hr. ft.°F.
    B.
    In steady state heat conduction, the only property of the substance which determines the temperature distribution, is the thermal conductivity.
    C.
    In unsteady state heat conduction, heat flows in the direction of temperature rise.
    D.
    In heat transfer by forced convection, Grashoff number is very important.

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  5. Open pan evaporators are preferred to be used, when the solution to be concentrated is

  6. A.
    scaling
    B.
    highly viscous
    C.
    corrosive
    D.
    salty

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  7. is termed as the __________ number.

  8. A.
    Grashoff
    B.
    Nusselt
    C.
    Prandtl
    D.
    Stanton

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  9. The maximum heat transfer co-efficient from steam heating will be attained when the steam is

  10. A.
    supersaturated
    B.
    saturated
    C.
    wet
    D.
    none of these

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  11. Kirchoff's law is applicable to

  12. A.
    monochromatic radiation only
    B.
    total radiation only
    C.
    both (a) and (b)
    D.
    only volumes and not to surfaces

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  13. In a forward feed multiple effect evaporator, the pressure is

  14. A.
    highest in last effect
    B.
    lowest in last effect
    C.
    same in all effects
    D.
    dependent on the number of effects

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  15. In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will

  16. A.
    increase
    B.
    decrease
    C.
    remain unchanged
    D.
    either increase or decrease; depends on the coolant flow rate

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  17. Which of the following situations can be approximated to a steady state heat transfer system ?

  18. A.
    A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmosheric air at 35°C.
    B.
    10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C.
    C.
    Boiling brine kept in open vessel when the bottom surface temperature of the vessel is maintained constant at 180°C.
    D.
    A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C.

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  19. Sensible heat absorbed by 1 lb of water when it is heated from 32 to 212°F may be around __________ BTU.

  20. A.
    180
    B.
    970
    C.
    3.97
    D.
    data insufficient, can't be predicted

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