Top 1000+ Solved Heat Transfer (HT) MCQ Questions Answer
Q. The rate of energy emission from unit surface area through unit solid angle,along a normal to the surface, is known as
a. emissivity
b. transmissivity
c. reflectivity
d. intensity of radiation
e. absorptivity.
Q. Emissivity of a white polished body in comparison to a black body is
a. higher
b. lower
c. same
d. depends upon the shape of body
e. none of the abov
Q. A grey body is one whose absorptivity
a. varies with temperature
b. varies with wavelength of the incident ray
c. is equal to its emissivity
d. does not vary with temperature an wavelength of the incident ray
e. none of the abov
Q. A non-dimensional number generally associated with natural convection heattransfer is
a. Grashoff number
b. Nusselt number
c. Weber number
d. Prandtl number
e. Reynold number.
Q. Fourier's law applies to the heat transfer by
a. Convection
b. Radiation
c. Conduction
d. All (A), (B) & (C)
Q. jH factor for heat transfer is not a function of the __________ number.
a. Reynolds
b. Nusselt
c. Grashoff
d. Both (B) & (C)
Q. The heat transfer by radiation from a mild steel surface is to be reduced by reducing theemissivity of the surface. This can be best achieved by
a. Painting the surface black
b. Painting the surface white (with aluminium paint)
c. Giving the surface a mirror finish
d. Roughening the surface
Q. In a heat exchanger, one transfer unit means
a. A section of the exchanger in which change in temperature of one stream equals the average driving force in the section
b. The size of the exchanger in which heat transfer rate is 1 kcal/hr
c. Both (A) and (B)
d. None of these
Q. Heat produced when a steady state current, I passes through an electrical conductor havingresistance, 'R' is
a. IR
b. I2R
c. IR2
d. I2R2
Q. A 2-4 heat exchanger involves
a. Only counter-flow of fluids
b. Only parallel-flow of fluids
c. Both counter and parallel-flow of the fluids
d. Smaller pressure drop compared to 1-2 exchanger
Q. In a multipass shell and tube heat exchanger, tube side return pressure loss is equal to__________ the velocity head.
a. Twice
b. Four times
c. Square root of
d. Square of
Q. In a shell and tube heat exchanger, the height of 25 percent cut baffles is equal to(where, D = inside diameter of shell).
a. 0.25 D
b. 0.50 D
c. 0.75 D
d. None of these
Q. Latent heat absorbed by 1 lb of water at 212°F, when it is changed to steam at 212°F, maybe around __________ BTU.
a. 180
b. 970
c. 3.97
d. None of these