According to Wien's displacement law, the wavelength \(\left(\lambda_m\right)\) corresponding to which the energy emitted by a black body maximum is inversely proportional to its absolute temperature (T).
i.e., \(\quad \lambda_m \propto \frac{1}{T}\)
\(\Rightarrow \quad \lambda_m=\frac{b}{T}\) [where, \(b=\) Wien's constant]
\(\lambda_m \cdot T=b\)