An object having a fixed emissivity of 0.725 radiates heat at a rate of 10 W when it is at an absolute temperature T.If its temperature is doubled to 2T,at what rate will it now radiate?
A)20 W
B)40 W
C)80 W
D)160 W
E)320 W

Question

Quizplus · Accepted Answer

According to Stefan-Boltzmann law, the rate of radiation emitted by an object is proportional to the fourth power of its temperature. Thus, the rate of radiation when the temperature is doubled to 2T will be:

(2^4)(10 W) = 16 x 10 W = 160 W

Therefore, the correct answer is D)160 W.

An Object Having a Fixed Emissivity of 0