Top 1000+ Solved Heat Transfer (HT) MCQ Questions Answer
Q. An ejector is used to
a. Increase pressure
b. Increase temperature
c. Remove condensate
d. None of these
Q. In a forward feed multiple effect evaporator, the pressure is
a. Highest in last effect
b. Lowest in last effect
c. Same in all effects
d. Dependent on the number of effects
Q. With increase in temperature, the thermal conductivity of most liquids
a. Increases
b. Decreases
c. Remain same
d. First increases upto a certain temperature and then becomes constant
Q. The film co-efficient between condensing vapour and metal wall increases with
a. Increasing temperature of the vapour
b. Decreasing temperature of the vapour
c. Increasing viscosity of the film of condensate
d. Increasing temperature drop
Q. In Fourier's law, the proportionality constant is called the
a. Heat transfer co-efficient
b. Thermal diffusivity
c. Thermal conductivity
d. Stefan-Boltzmann constant
Q. The non-dimensional temperature gradient in a liquid at the wall of a pipe is the
a. Heat flux
b. Nusselt number
c. Prandtl number
d. Schmidt number
Q. When the ratio of the Grashoff number and to the square of Reynolds number is one, the dominant mechanism of heat transfer is:
a. Free convection
b. Entry length problem in laminar forced conduction (developing thermal boundary layer)
c. Mixed convection (both free and forced)
d. Forced convection
Q. "The ratio of the total emissive power to the absorptivity for all bodies is same at ther-mal equilibrium". This is __________ law.
a. Kirchoff’s
b. Planck's
c. Wien's displacement
d. Stefan-Boltzmann
Q. For hot feed, forward feeding as compared to backward feeding results in __________economy.
a. Increased
b. Decreased
c. No effect on
d. None of these
Q. Pick out the wrong statement.
a. Fluid movement under the influence of buoyant forces resulting from change in density takes place in case of natural convection
b. The ratio NNu/NRe . Npr is called the Stanton number
c. The Peclet number is a measure of the ratio of energy transport by convection to that by conduction
d. The Colburn jH factor for heat transfer is given by Nst Npr
Q. In sub-cooled boiling,
a. Temperature of the heating surface is less than the boiling point of the liquid
b. Temperature of the heating surface is more than the boiling point of the liquid
c. Bubbles from heating surface are absorbed by the mass of the liquid
d. Very large vapour space is necessary
Q. Which is the best tube arrangement (in a shell and tube heat exchanger) if the fluids areclean and non-fouling?
a. Square pitch
b. Triangular pitch
c. Diagonal square pitch
d. None of these