The wavelength of the radiation emitted by a black body is $1 \,mm$ and Wien's constant is $3 \times 10^{-3} \,mK$. Then the temperature of the black body will be (in $\,K$)

When an iron rod is heated, the variation of colour from dull red to white can be explained by

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 $X$?

$A$ black body at a temperature of $1640 \ K$ has the wavelength corresponding to maximum emission equal to $1.75 \ \mu m$. Assuming the moon to be a perfectly black body,the temperature of the moon,if the wavelength corresponding to maximum emission is $14.35 \ \mu m$,is ...... $K$.

Write the temperature of the surfaces of the Moon and the Sun according to Wien's displacement law.

The black body spectrum of an object $O_1$ is such that its radiant intensity (i.e.,intensity per unit wavelength interval) is maximum at a wavelength of $200\,nm$. Another object $O_2$ has the maximum radiant intensity at $600\,nm$. The ratio of power emitted per unit area by source $O_1$ to that of source $O_2$ is