Top 1000+ Solved Heat Transfer (HT) MCQ Questions Answer
Q. DBA = DAB, in case of
a. Stagnet diffusion
b. Equimolar counter diffusion
c. Either of (A) and (B) above
d. None of the above
e. 2.6 cm2/sec
Q. Unsaturated vapours
a. Do not obey gas laws
b. Fully obey gas laws
c. Obey Boyle's law but not Charle's law
d. Partly obey gas laws depending upon the degree of unsaturations
e. None of the above
Q. A substance above critical temperature exists as
a. Solid
b. Liquid
c. Wet vapour
d. Gas
e. Dry vapour
Q. Which dimensionless number indicates the relative strength of the buoyant to viscous forces?
a. Froude's number
b. 37,500 kg
c. Prandtl number
d. Weber number
e. Grashoff number
Q. In case the hydrodynamic and thermal boundary layers are identical for a fluid flowing over a heated plate
a. The value of Prandtl number must be 0.5
b. The plate surface must be smooth
c. The plate must be of low thermal conductivity
d. The value of Prandtl number thust be 1
e. The value of Prandtl number must be zero
Q. A high value of Prandtl number indicates
a. rapid diffusion of momentum by viscous action compared to diffusion of energy
b. relative heat transfer by conduction to convection
c. rapid heat transfer by forced convection to natural convection
d. None of the above
e. 37,500 kg
Q. Elongation of a rod when heated
a. Is proportional to original length
b. Is proportional to length
c. Is inversely proportional to linear strain
d. Is inversely proportional to original length
e. Does not depend on its length
Q. A dimensionless number which is the ratio of mass heat flow rate to the heat flow rate by conduction under a unit temperature gradient and through a thickness L is known as
a. Nusselt number
b. Prandtl number
c. Weber number
d. Grashof number
e. Peclet number
Q. The surface temperatures of a flat wall are 650?C and 450?C respectively and the thermal conductivity of the wall material is 0.30 kcal/m-hr-?C. The heat flux for a wall of 20 cm thickness will be
a. 60 kcal/m2-hr
b. 600 kcal/m2-hr
c. 120 kcal/m2-hr
d. 300 kcal/m2-hr
e. 450 kcal/m2-hr
Q. Which of the following is a minimum boiling azeotrope?
a. Acetone-chloroform
b. Molasses-water
c. Benzene-toluene
d. Iso-butanol-water
e. Carbon disulphide-acetone
Q. In a psychrometric chart the abscissa represents
a. Specific humidity
b. Relative humidity
c. Enthalpy
d. Dry bulb temperature
e. Wet bulb temperature
Q. For handling severely scaling liquids which of the following evaporator will be preferred?
a. Horizontal tube type
b. Long vertical tube type
c. Agitated film type
d. Short vertical tube
e. None of the above
Q. The factor which affects nucleate pool boiling is
a. Material of heating surface
b. Surface condition of heating surface
c. Physical properties of liquid
d. Pressure
e. All of the above
Q. If the amount of radiant energy received per unit area per second from the sun is measured at the Earth, Mars and Jupiter it will be
a. in the decreasing order - Jupiter, Mars, Earth
b. in the increasing order - Jupiter, Mars, Earth
c. identical on all the three planets
d. 37,500 kg
e. in the increasing order - Earth, Mars, Jupiter
Q. Two bodies one hot and the other cold are kept in vacuum. What will happen to the temperature of the hot body after sometime?
a. Increases due to convection
b. Remains the same
c. Decreases due to convection
d. Increases due to radiation
e. Decreases due to radiation