Assertion : A normal body can radiate energy more than a perfectly black body.
Reason : A perfectly black body is always black in colour.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reasonb is false
D. If both assertion and reason are false.

Answer

B

Explanation

Both the assertion and reason are false.
A hollow metallic container with a small orifice and coated with lamp black inside is taken as a source of black-body radiation when it is heated. A closed container cannot act as a source of blackbody because it cannot absorb all radiations. All metals are not black bodies. A black body is described above. It is the hole the absorbs and emits the radiation, which is treated as a black body and not even the whole container. Assertion is only partially correct. The statement given in the reason is wrong.