$A$ body has a transmission power of $1/6$ and a reflection power of $1/3$. Find its absorption power.

If a black body at $400 \ K$ surrounded by atmosphere at $300 \ K$ has a rate of cooling '$R_0$',the same body at $900 \ K$,surrounded by the same atmosphere,will have a rate of cooling nearly:

For a perfect black body,the absorption coefficient is

''$A$ perfect black body is black in colour.'' Is this statement true or false?

Which of the following statements is wrong?

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