$x$ joule of heat is incident on a body. Out of it, the total heat reflected and transmitted by it is $y$ joule. The absorption coefficient of the body is

$A$ hot and a cold body are kept in a vacuum,separated from each other. Which of the following causes a decrease in the temperature of the hot body?

$A$ total radiation of $400 \ J$ is incident on a body. If $20\%$ of the radiation is reflected and $120 \ J$ is absorbed,find the percentage of the transmittive power.

Surface temperature of the sun is of the order of $K$.

Two identical objects $A$ and $B$ are at temperatures $T_A$ and $T_B$ respectively. Both objects are placed in a room with perfectly absorbing walls maintained at temperature $T$ $(T_A > T > T_B)$. The objects $A$ and $B$ attain temperature $T$ eventually. Which one of the following is the correct statement?

The absorption coefficient of an open window is: