Top 50+ Solved Heat Transfer MCQ Questions Answer
Q. All radiations in a black body are
a. reflected
b. partly reflected and partly absorbed
c. transmitted
d. absorbed
Q. According to Kirchoff's law, ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a
a. grey body
b. brilliant white polished body
c. red hot body
d. black body
Q. According to Stefan-Boltzmann law, ideal radiators emit radiant energy at a rate proportional to
a. absolute temperature
b. square of temperature
c. fourth power of absolute temperature
d. cube of absolute temperature.
Q. The unit of Stefan Boltzmann constant is
a. watt/cm2 °K
b. watt/cm4 °K
c. watt2/cm °K4
d. watt/cm2 °K4
Q. Stefan Boltzmann law is applicable for heat transfer by
a. conduction
b. convection
c. radiation
d. conduction and radiation combined
Q. The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of aperfectly black body. This statement is known as
a. Krichoff's law
b. Stefan's law
c. Wien' law
d. Planck's law
Q. The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit
a. temperature
b. thickness
c. area
d. time
Q. The ratio of the energy absorbed by the body to total energy falling on it is called
a. absorptive power
b. emissive power
c. absorptivity
d. emissivity
Q. The amount of radiation mainly depends on
a. nature of body
b. temperature of body
c. type of surface of body
d. all of the above
Q. The emissive power of a body depends upon its
a. temperature
b. wave length
c. physical nature
d. all of the above
Q. Two plates spaced 150 mm apart are maintained at 1000°C and 70°C. The heat transfer will take place mainly by
a. convection
b. free convection
c. forced convection
d. radiation
Q. In regenerative type heat exchanger, heat transfer takes place by
a. direct mixing of hot and cold fluids
b. a complete separation between hot and cold fluids
c. flow of hot and cold fluids alternately over a surface
d. indirect tr
Q. A perfect black body is one which
a. is black in colour
b. reflects all heat
c. transmits all heat radiations
d. absorbs heat radiations of all wave lengths falling on it