If $25\%$ of the total incident radiation $Q = 500 \, J$ is absorbed and $105 \, cal$ is transmitted,calculate the percentage of reflected power.

If the transmission power of a surface is $\frac{1}{9}$ and the reflective power is $\frac{1}{6}$,then what is its absorptive power?

The temperature of a blackbody radiation enclosed in a container of volume $V$ is increased from $100^{\circ} C$ to $1000^{\circ} C$. The heat required in the process is

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 $2\ T$ and $3\ T$ respectively. The temperature of the middle (i.e.,second) plate under steady-state condition is

The coefficient of absorption $(a)$ and the coefficient of reflection $(r)$ of a thin uniform plate are $0.77$ and $0.17$ respectively. If $250 \ kcal$ of heat is incident on the surface of the plate,the quantity of heat transmitted $(t)$ is: (in $kcal$)

Which of the following is best close to an ideal black body?