$A$ black body radiates at the rate of $W$ watts at a temperature $T$. If the temperature of the body is reduced to $T/3$,it will radiate at the rate of (in Watts):

The surface of a black body is at a temperature $727^{\circ} C$ and its cross-section is $1 \,m^2$. Heat radiated from this surface in one minute in joules is (Stefan's constant $=5.7 \times 10^{-8} \,W / m^2 / K^4$ )

$A$ black body radiates heat energy at the rate of $2 \times 10^5 \, J/s \cdot m^2$ at a temperature of $127 \, ^\circ C$. The temperature of the black body at which the rate becomes $32 \times 10^5 \, J/s \cdot m^2$ is ....... $^\circ C$.

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

Two bodies $A$ and $B$ at temperatures $T_1 \ K$ and $T_2 \ K$ respectively have the same dimensions. Their emissivities are in the ratio $1: 3$. If they radiate the same amount of heat per unit area per unit time,then the ratio of their temperatures $(T_1: T_2)$ is

The heat radiated per unit area in $1\,hour$ by a furnace whose temperature is $3000\,K$ is $(\sigma = 5.7 \times 10^{-8}\,W\,m^{-2}\,K^{-4})$.