Q. Absorptivity of a body will be equal to its emissivity
✅ Correct Answer: (C)
when system is under thermal equi-librium
Heat Transfer MCQs | Page - 1
Dear candidates you will find MCQ questions of Heat Transfer here. Learn these questions and prepare yourself for coming examinations and interviews. You can check the right answer of any question by clicking on any option or by clicking view answer button.
Q. A steam pipe is to be insulated by two insulating materials put over each other. For best results
✅ Correct Answer: (A)
better insulation should be put over pipe and better one over it
Q. A perfect black body is one which
✅ Correct Answer: (D)
absorbs heat radiations of all wave lengths falling on it
Q. A non-dimensional number generally associated with natural convection heat transfer is
✅ Correct Answer: (A)
Grashoff number
Q. A grey body is one whose absorptivity
✅ Correct Answer: (C)
is equal to its emissivity
Q. 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is
✅ Correct Answer: (A)
0.45
Q. If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of
✅ Correct Answer: (C)
81
Q. Depending on the radiating properties, body will be transparent when
✅ Correct Answer: (C)
p = 0, T= l, and a = 0
Q. According of Kirchhoff's law,
✅ Correct Answer: (D)
ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body.
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