If wavelengths of maximum intensity of radiations emitted by the sun and the moon are $0.5 \times 10^{-6} \ m$ and $10^{-4} \ m$ respectively,the ratio of their temperatures is

The wavelength of radiation emitted from a body depends on .......

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

$A$ black body emits radiation with maximum intensity at a wavelength of $5000 \mathring{A}$ at a temperature of $1227^\circ C$. If its temperature is increased by $1000^\circ C$, the new wavelength of maximum intensity will be ...... $\mathring{A}$.

Wien's displacement law expresses the relationship between:

The black discs $x, y$ and $z$ 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