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 $Q$)?

Two spheres of the same material have radii $1 \; m$ and $4 \; m$ and temperatures $4000 \; K$ and $2000 \; K$ respectively. The ratio of the energy radiated per second by the first sphere to that by the second is

The total radiant energy per unit area,normal to the direction of incidence,received at a distance $R$ from the centre of a star of radius $r$,whose outer surface radiates as a black body at a temperature $T \ K$ is given by

If the temperature of a black body is increased from $27^{\circ}C$ to $327^{\circ}C$,the radiation emitted increases by a factor of:

Obtain the equation for the rate of emission of heat for a perfect black body by using the Stefan-Boltzmann law.

Energy is being emitted from the surface of a black body at $127\,^{\circ}C$ temperature at the rate of $1.0 \times 10^6\,J/s\cdot m^2$. The temperature of the black body at which the rate of energy emission is $16.0 \times 10^6\,J/s\cdot m^2$ will be ......... $^{\circ}C$.