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Chemical Engineering :: Heat Transfer

  1. The ratio of velocity head to tube side return loss in case of a multipass shell and tube heat exchanger is

  2. A.
    2
    B.
    1/2
    C.
    4
    D.
    1/4

  3. Terminal point temperature differences between fluids in case of a heat exchanger is termed as

  4. A.
    approach.
    B.
    log mean temperature difference.
    C.
    arithmetic mean temperature difference.
    D.
    geometric mean temperature difference.

  5. LMTD can't be used as such without a correction factor for the

  6. A.
    multipass heat exchanger.
    B.
    baffled heat exchanger.
    C.
    condensation of mixed vapour in a condenser.
    D.
    all (a) (b) and (c).

  7. Fqra cold viscous feed, backward feed gives __________ than forward feed.

  8. A.
    a higher capacity
    B.
    a lower capacity
    C.
    lower economy
    D.
    none of these

  9. Walls of a cubical oven are of thickness l, and they are made of material of thermal conductivity k. The temperature inside the oven is 100°C and the inside heat transfer co-efficient is 3k/l. If the wall temperature on the outside is held at 25°C, what is the inside wall temperature in degree centigrade ?

  10. A.
    35.5
    B.
    43.75
    C.
    81.25
    D.
    48.25

  11. Overall heat transfer co-efficient of a particular tube is U1. If the same tube with some dirt deposited on either side has coefficient U2, then

  12. A.
    U1 = U2
    B.
    U2 > U1
    C.
    U1 > U2
    D.
    U1 = dirt factor - U2

  13. In SI units, thermal conductivity is expressed in

  14. A.
    Watt/m.°K
    B.
    Watt/m2. °K
    C.
    Watt/m2. °K
    D.
    Watt/m4. °K

  15. Boiling point of a solution according to Duhring's rule is a linear function of the __________ of water.

  16. A.
    boiling point (at the same pressure)
    B.
    viscosity
    C.
    density
    D.
    thermal conductivity

  17. The overall resistance for heat transfer through a series of flat resistance, is the __________ of the resistances.

  18. A.
    average
    B.
    geometric mean
    C.
    product
    D.
    sum

  19. At what value of Prandtl number, conduction is negligible in the turbulent core of a fluid flowing through a heated pipe ?

  20. A.
    0.5
    B.
    < 0.5
    C.
    > 0.6
    D.
    < 0.1