$A$ black body at a temperature of $127^{\circ}C$ radiates heat at the rate of $1 \ cal/cm^2 \cdot s$. At a temperature of $527^{\circ}C$,the rate of heat radiation from the body in $cal/cm^2 \cdot s$ will be:

Three very large plates of the same area are kept parallel and close to each other. They are considered as ideal black surfaces and have very high thermal conductivity. The first and third plates are maintained at temperatures $2T$ and $3T$ respectively. The temperature of the middle (i.e.,second) plate under steady-state condition is

Compare the rate of loss of heat from a metal sphere at $627^{\circ} C$ with the rate of loss of heat from the same sphere at $327^{\circ} C$,if the temperature of the surrounding is $27^{\circ} C$. (nearly)

$A$ black body radiates $20\,W$ at temperature $227^{\circ}C$. If the temperature of the black body is changed to $727^{\circ}C$,then its radiating power will be ..... $W$.

$A$ rectangular metal plate $8 \ cm \times 4 \ cm$ at $127^{\circ} C$ emits $E \ Js^{-1}$. If both length and breadth are halved and the temperature is raised to $327^{\circ} C$,the rate of emission is

If a black body emits $0.5 \ J$ of energy per second when it is at $27^{\circ} C$,then the amount of energy emitted by it when it is at $627^{\circ} C$ will be (in $J$)