Assertion : For higher temperature, the peak emission wavelength of a black body shifts to lower wavelengths.
Reason : Peak emission wavelength of a black body is proportional to the fourth power of temperature.

Options

A. If both, Assertion and Reason are true and Reason is the correct explanation of the Asserrion.
B. If both,Assertion and Reason are true but Reason is not a correct explanation of the Assertion.
C. If Assertion is true but the Reason is false.
D. If both, Assertion and Reason are false.

Answer

C

Explanation

According to Wien's displcement law, for a black body `lambda_(m)T=a` constant or `lambda_(m) prop 1/T`.
It means as temperature `(T)` of black body increases, peak emission wavelength `lambda_(m)` of the black body decreases, i.e.,shifts towards lower wavelength side. Thus Assertion is true. Here, Reason is false because energy emmitted per secnd per unit area of unit area of balck body is directly proportional to fourth power of temperature, i.e., `E= sigmaT^(4)` (According to Stefan's law.)