If the temperature of back body is doubled, the frequency at which the spectral intensity becomes maximum,…
If the temperature of back body is doubled, the frequency at which the spectral intensity becomes maximum, will be
unchanged
four times
doubled
halved
Solution
According to the Wein's displacement law:
$\lambda_m \propto \frac{1}{T}$
And the relation between wavelength and frequency is:
$\begin{aligned} & \lambda \propto \frac{1}{f} \\ & \Rightarrow f \propto T\end{aligned}$
Thus, if $T$ is doubled, the frequency at which the spectral intensity becomes maximum $f$ is also doubled.