Q.The surface temperature of a certain star is estimated to be $6000\ \text{K}$. Treating the star as a black body and taking Wien's constant as $b = 2.898\times10^{-3}\ \text{m K}$, find the wavelength at which the star's radiation is most intense.

A black body absorbs (and, by Kirchhoff's law, most efficiently emits) radiation at every wavelength; its emission spectrum, plotted against wavelength at a fixed temperature, rises to a single peak and falls away again. Wien's displacement law states that the peak wavelength $\lambda_m$ is inversely proportional to absolute temperature, $\lambda_m T = b$ (Wien's constant, $b \approx 2.898 …