What is the ratio of energy emitted by a black body at temperatures $27^{\circ}C$ and $927^{\circ}C$?

$A$ black body is at temperature $827^{\circ}\text{C}$. The rate at which it emits energy is proportional to

The Sun emits electromagnetic energy at a rate of $3.9 \times 10^{25} \ W$. Its radius is $6.96 \times 10^8 \ m$. The intensity of sunlight at the solar surface in $W \ m^{-2}$ is:

The energy emitted per second by a black body at $27^{\circ}C$ is $10\;J$. If the temperature of the black body is increased to $327^{\circ}C$,the energy emitted per second will be ......... $J$.

Assuming the sun to be a spherical body of radius $R$ at a temperature of $T \ K$,evaluate the total radiant power incident on Earth at a distance $r$ from the sun (where the radius of the Earth is $r_0$).

The temperature of a lamp filament is $2100 \ K$ and its surface area is $4 \times 10^{-4} \ m^2$. If the emissivity of the filament is $0.453$,then the power of the lamp will be ....... $W$.