Wien's displacement law expresses the relation between:

$A$ perfect black body has a maximum wavelength $\lambda_m$ at a temperature of $2000 \, K$. What will be its maximum wavelength at a temperature of $3000 \, K$?

The Sun emits light with a maximum wavelength of $510 \, nm$,while another star $X$ emits light with a maximum wavelength of $350 \, nm$. What is the ratio of the surface temperature of the Sun to that of star $X$?

The maximum wavelength of radiation emitted by a star is $289.8 \ nm$. The intensity of radiation for the star is (Given: Stefan's constant $\sigma = 5.67 \times 10^{-8} \ W \ m^{-2} \ K^{-4}$,Wien's constant $b = 2898 \ \mu m \ K$)

The radiation energy density per unit wavelength at temperature $T$ is maximum at a wavelength $\lambda_0$. At temperature $2T$,it will have a maximum at a wavelength

Three black discs $x, y, z$ have radii $1 \ m, 2 \ m$ and $3 \ m$ respectively. The wavelengths corresponding to maximum intensity are $200 \ nm, 300 \ nm$ and $400 \ nm$ respectively. The relation between emissive power $E_x, E_y$ and $E_z$ is: