An object having an emissivity 0.725 radiates heat at a rate of 10 W when it is at a temperature T.If its temperature is doubled,it will radiate at a rate of
A)160 W
B)80 W
C)40 W
D)20 W

Question

Quizplus · Accepted Answer

The rate of heat radiation is proportional to the fourth power of the temperature (Stefan-Boltzmann Law). If the temperature is doubled, the radiation rate increases by a factor of 2^4 = 16. Therefore, 10 W * 16 = 160 W.

An Object Having an Emissivity 0