Top 150+ Solved Thermal Engineering 1 MCQ Questions Answer
Q. LMTD in case of counter flow heat exchanger as compared-to parallel flow heat exchanger is
a. higher
b. lower
c. same
d. depends on the area of heat exchanger
Q. In counter flow heat exchangers
a. both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state
b. both the fluids at inlet are in their hottest state
c. both the fluids .at exit are in their hottest state
d. one fluid is in hottest state and other in coldest state at inlet
Q. Fourier's law of heat conduction is valid for
a. one dimensional cases only
b. two dimensional cases only
c. three dimensional cases only
d. regular surfaces having non-uniform temperature gradients
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