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

Two black bodies at temperatures $327^{\circ} C$ and $427^{\circ} C$ are kept in an evacuated chamber at $27^{\circ} C$. The ratio of their rates of loss of heat are :

The power radiated by a black body is $P$ and it radiates maximum energy at wavelength $\lambda_0$. If the temperature of the black body is now changed so that it radiates maximum energy at wavelength $\frac{3}{4}\lambda_0$,the power radiated by it becomes $nP$. The value of $n$ is

$A$ black body is at a temperature $300 K$. It emits energy at a rate,which is proportional to

Two spherical black bodies of radii $R_1$ and $R_2$ and with surface temperatures $T_1$ and $T_2$ respectively radiate the same power. The ratio of $R_1$ to $R_2$ will be

If the temperature of a black body increases from $7^{\circ}C$ to $287^{\circ}C$,then what is the ratio of the rate of energy emission?