The temperatures of two bodies $A$ and $B$ are $727^{\circ}C$ and $127^{\circ}C$. The ratio of the rate of emission of radiations will be:

Suppose the Sun is a spherical body of radius $r$ with a surface temperature of $t \, ^\circ C$. It radiates energy like a black body. The power received per unit area at a distance $R$ from the center of the Sun will be: ($\sigma$ is the Stefan-Boltzmann constant)

The rate of dissipation of heat by a black body at temperature $T$ is $Q$. What will be the rate of dissipation of heat by another body at temperature $2T$ and emissivity $0.25$ (in $Q$)?

$A$ black body radiates energy at the rate of $E \text{ W/m}^2$ at a high temperature $T \text{ K}$. When the temperature is reduced to $\left(\frac{T}{2}\right) \text{ K}$, the radiant energy is

If the temperature of the sun is doubled,the rate of energy received by the earth will be increased by a factor of:

The radiation emitted by a star $A$ is $10000$ times that of the sun. If the surface temperatures of the sun and the star $A$ are $6000 \ K$ and $2000 \ K$ respectively, the ratio of the radii of the star $A$ and the sun is: (in $: 1$)