Wien's displacement law: The wavelength \(\left(\lambda_{m}\right)\) emitted with maximum intensity by a black body is inversely proportional to its absolute temperature.
Mathematically,
$$
\lambda_{n} \propto \frac{1}{T} \text { i.e., } \lambda_{a}=b \cdot \frac{1}{T}
$$
where b = constant called Wien's constant.
Significance:
a. It can be used to estimate very high temperature such as surface temperature of stars, sun, moon, celestial bodies etc.
b. It explains the common observation of the change of colour of a solid from dull red to yellow and then to white on heating.
c. As the temperature increases, the maximum intensity of radiation shifts towards the shorter wavelength side. Thus Wien's law is also called displacement law.
