Top 1000+ Solved Heat Transfer (HT) MCQ Questions Answer
Q. For condensation of pure vapors, if the heat transfer co-efficients in filmwise and drop-wisecondensation are respectively hf and hd, then
a. hf = hd
b. hf > hd
c. hf < hd
d. hf could be greater or smaller than hd
Q. Heat transfer in the laminar sub-layer in case of a liquid flowing through a pipe, is mostlyby
a. Eddies current
b. Conduction
c. Convection
d. None of these
Q. If the baffle spacing in a shell and tube heat exchanger increases, then the Reynolds number of the shell side fluid
a. Remains unchanged
b. Increases
c. Increases or decreases depending on number of shell passes
d. Decreases
Q. __________ heat exchanger is the most suitable, when the temperature of shell side fluid is much higher than that of tube side.
a. Single pass, fixed tube sheet
b. U-tube
c. Three pass, fixed tube sheet
d. None of these
Q. Fouling factor
a. Is a dimensionless quantity
b. Does not provide a safety factor for design
c. Accounts for additional resistances to heat flow
d. None of these
Q. Evaporation of 1kg of water from a solution in a single effect evaporator requires about__________ kg of steam.
a. 0.4 - 0.6
b. 1-1.3
c. 1.8-2
d. 2 - 2.4
Q. As the difference between the wall temperature and bulk temperature increases, the boilingheat transfer co-efficient
a. Continues to increase
b. Continues to decrease
c. Goes through a minimum
d. Goes through a maximum
Q. Thermal conductivities of most of the liquids __________ with rise in temperature.
a. Increases
b. Decreases
c. Remains unchanged
d. May increase or decrease; depends on the liquid
Q. The equivalent diameter for pressure drop is __________ that for heat transfer.
a. Smaller than
b. Greater than
c. Equal to
d. Not related with
Q. The purpose of providing a 'catchall' in the vapor line of an evaporator is to
a. Create vacuum
b. Regulate the vapor flow
c. Vent the non-condensable gases
d. Arrest the entrained liquid
Q. Which of the following accessories is provided in the vapor line of an evaporator forremoving the entrained liquid?
a. Bleed point
b. Vent
c. Catchall
d. Baffle
Q. Removal of __________ heat is involved in the condensation of a vapor under saturatedconditions.
a. Super
b. Sensible
c. Latent
d. Both (B) & (C)
Q. In a heat exchanger, floating head is provided to
a. Facilitate cleaning of the exchanger
b. Increase the heat transfer area
c. Relieve stresses caused by thermal expansion
d. Increase log mean temperature gradient
Q. Electromagnetic radiations propagate in vacuum with a velocity of __________metre/second.
a. 3 × 105
b. 3 × 108
c. 3 × 1010
d. 3 × 1012