The rate of radiation by a black body is $R$ at temperature $T$. Another body has the same area but an emissivity of $0.2$ and a temperature of $3T$. Its rate of radiation is: (in $R$)

For a black body at temperature $727^{\circ} C$,its radiating power is $60\; W$ and the temperature of the surrounding is $227^{\circ} C$. If the temperature of the black body is changed to $1227^{\circ} C$,then its radiating power will be ..... $W$.

The ratio of radiant energies radiated per unit surface area by two bodies is $16 : 1$. The temperature of the hotter body is $1000 \ K$. Then,the temperature of the colder body will be ....... $K$.

The temperatures of two bodies $A$ and $B$ are $727^{\circ}C$ and $327^{\circ}C$ respectively. What is the ratio of their rates of energy emission $H_A : H_B$?

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

$A$ certain stellar body has radius $50 \,R_{s}$ and temperature $2 \,T_{s}$ and is at a distance of $2 \times 10^{10} \,AU$ from the earth. Here,$AU$ refers to the earth-sun distance and $R_{s}$ and $T_{s}$ refer to the sun's radius and temperature,respectively. Take both the star and the sun to be ideal black bodies. The ratio of the power received on earth from the stellar body as compared to that received from the sun is close to