Q151
Absorptivity of a body will be equal to its emissivity
A.
At all temperatures
B.
At one particular temperature
C.
When system is under thermal equilibrium
AnswerD.
At critical temperature
Answer: Option C
Solution
Answer: Option C
Solution:
Kirchhoff's law states that For an arbitrary body emitting and absorbing thermal radiation in thermodynamic equilibrium, the emissivity is equal to the absorptivity.