Find the rate of radiation emitted per unit area per unit time by a black body at a temperature of $10^{3} \ K$ (in $J \ m^{-2} \ s^{-1}$).

When the temperature of a black body increases,it is observed that the wavelength corresponding to maximum energy changes from $0.26 \mu m$ to $0.13 \mu m$. The ratio of the emissive powers of the body at the respective temperatures is

$A$ black body is at $727^\circ C$. It emits energy at a rate which is proportional to

Solar constant $(S)$ depends upon the temperature of the Sun $(T)$ as ........

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 $Q$)?

$Assertion :$ Bodies radiate heat at all temperatures.
$Reason :$ Rate of radiation of heat is proportional to the fourth power of absolute temperature.