Top 1000+ Solved Heat Transfer (HT) MCQ Questions Answer
Q. Which of the following is a case of steady state heat transfer
a. I.C. engine
b. air preheaters
c. heating of building in winter
d. all of the above
e. none of the abov
Q. Total heat is the heat required to
a. change vapour into liquid
b. change liquid into vapour
c. increase the temperature of a liquid or vapour
d. convert water into steam and superheat it
e. convert saturated steam into dry steam.
Q. Cork is a good insulator because it has
a. free electrons
b. atoms colliding frequency
c. low density
d. porous body
e. all of the abov
Q. Thermal conductivity of water in general with rise in temperature
a. increases
b. decreases
c. remains constant
d. may increase or decrease depending on temperature
e. none of the abov
Q. Temperature of steam at around 540°C can be measured by
a. thermometer
b. radiatiouv pyrometer
c. thermistor
d. thermocouple
e. thermopil
Q. Thermal conductivity of air at room temperature in kcal/m hr °C is of the orderof
a. 0.002
b. 0.02
c. 0.01
d. 0.1
e. 0.5.
Q. The time constant of a thermocouple is
a. the time taken to attain the final temperature to be measured
b. the time taken to attain 50% of the value of initial temperature difference
c. the time taken to attain 63.2% of the value of initial temperature difference
d. determined by the time taken to reach 100°C from 0°C
e. none of the abov
Q. Thermal conductivity of air with rise in temperature
a. increases
b. decreases
c. remains constant
d. may increase or decrease depending on temperature
e. none of the abov
Q. Heat flows from one body to other when they have
a. different heat contents
b. different specific heat
c. different atomic structure
d. different temperatures
e. none of the abov
Q. Minimum recommended baffle spacing in a shell and tube heat exchanger is about(where, D = shell diameter).
a. 0.2 D
b. 0.5 D
c. 0.66 D
d. 0.80 D
Q. For heat flow through very thick walled cylinder, use _________mean radius.
a. Arithmetic
b. Logarithmic
c. Geometric
d. Either (A) or (C)
Q. Corrosiveness of steam condensate is due to the presence of
a. CO2
b. Dissolved O2
c. Both (A) & (B)
d. Neither (A) nor (B)
Q. Solid angle subtended by the finite surface at the radiating element is
a. Called the view factor
b. Called the angle of vision
c. Proportional to the square of the distance between surfaces
d. Expressed in terms of radians
Q. LMTD for evaporators & condensers for a given terminal parameters & set of conditions for counter-flow is equal to that for parallel flow. In such heat exchangers, with one of the fluids condensing or evaporating, the surface area required is the least in the __________ flow.
a. Parallel
b. Mixed
c. Counter flow
d. Same in either 'a', b' or 'c'