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Mechanical Engineering · Q50

Heat And Mass Transfer

Engineering and GATE · Mechanical Engineering · question 50

Q50

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
Answer

Answer: Option D

Solution

Answer: Option D
Solution:
A perfect blackbody is one that absorbs all incoming light and does not reflect any. At room temperature, such an object would appear to be perfectly black . However, if heated to a high temperature, a blackbody will begin to glow with thermal radiation