Question

The absorptive power of a perfectly black body is:

• A. $Zero$
• B. $Infinity$
• C. $1.5$
• D. $1$

Answer 1

The correct option is D $1$

The absorptive power of a body or a surface is defined as the ratio of the energy absorbed in a given time to the radiant energy incident on it at the same instant of time. The absorptive power of a black body is $1$ because it absorbs radiant energy of all wavelengths incident on it.