For a perfectly black body,its absorptive power is

Which instrument is used to detect infrared rays?

The following graph shows the correct variation in the intensity of heat radiations emitted by a black body with respect to frequency at different fixed temperatures. Identify the correct graph.

Two thermometers $A$ and $B$ are exposed to sunlight. The bulb of $A$ is painted black,but that of $B$ is not painted. Which of the following statements is correct regarding this case?

When $p$ calories of heat is given to a body,it absorbs $q$ calories; then the absorption power of the body will be

Heat energy is incident on the surface of a material at the rate of $1000 \ J \ min^{-1}$. If the coefficient of absorption is $0.8$ and the coefficient of reflection is $0.1$,then the amount of heat energy transmitted through the material in $5$ minutes is: (in $J$)