Top 1000+ Solved Heat Transfer (HT) MCQ Questions Answer
Q. For __________ Prandtl number values, the heat conduction will be negligible in the bufferzone.
a. Extremely low
b. Low
c. High
d. No
Q. Planck's distribution law is valid for __________ bodies.
a. Black
b. White
c. Coloured
d. All (A), (B) & (C)
Q. Electro-magnetic spectrum range, which is important for radiation varies from __________microns.
a. 1 to 100
b. 0.5 to 50
c. 10 to 100
d. 100 to 1000
Q. In a shell and tube heat exchanger, square pitch compared to triangular pitch
a. Gives a higher shell side pressure drop
b. Gives a lower shell side pressure drop
c. Can pack more surface area into a shell of given diameter
d. None of these
Q. A body cools down from 75°C to 70°C in 10 minutes. It will cool down from 70° C to 65° Cin __________ minutes.
a. 10
b. > 10
c. < 10
d. Either (B) or (C), depends on the mass of the body
Q. In a gas-liquid shell and tube heat exchanger, the
a. Presence of a non-condensable gas decreases the condensing film co-efficient
b. Gases under high pressure are routed through the tube side, because high pressure gases are corrosive in nature
c. Gases to be heated/cooled is normally routed through the shell side, because the corrosion caused by the cooling water or steam condensate remain localised to the tubes
d. All 'a', 'b' & 'c'
Q. For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it
a. Occupies smaller space
b. Is more economical
c. Is easy to operate and maintain
d. All (A), (B) and (C)
Q. Terminal point temperature differences between fluids in case of a heat exchanger is termed as
a. Approach
b. Log mean temperature difference
c. Arithmetic mean temperature difference
d. Geometric mean temperature difference
Q. The Stefan-Boltzmann constant depends on the
a. Medium
b. Temperature
c. Surface
d. None of these
Q. A composite wall consists of two plates A and B placed in series normal to the flow of heat. The thermal conductivities are kA and kB and the specific heat capacities are CPA and CPB for plates A and B respectively. Plate B has twice the thickness of plate A. At steady state, the temperature difference across plate A is greater than that across plate B, when
a. CPA > CPB
b. CPA < CPB
c. kA < 0.5 kB
d. kA >2 kB
Q. In a shell and tube type heat exchanger, the floating tube bundle heat arrangement is used
a. In low range of temperature differences
b. In high range of temperature differences
c. Because of its low cost
d. To prevent corrosion of the tube bundles
Q. Overall heat transfer co-efficient of a particular tube is U1. If the same tube with some dirtdeposited on either side has coefficient U2, then
a. U1 = U2
b. U2 > U1
c. U1 > U2
d. U1 = dirt factor - U2
Q. In forced convection, the Nusselt number is a function of
a. Re and Pr
b. Re and Gr
c. Pr and Gr
d. Re and Sc
Q. Maximum heat transfer rate is achieved in __________ flow.
a. Co-current
b. Counter-current
c. Turbulent
d. Laminar
Q. Radiator of an automobile engine is a __________ type of heat exchanger.
a. Co-current
b. Cross-current
c. Counter-current
d. Direct contact