Assertion : A hollow metallic closed container maintained at a uniform temperature can act as a source of black body radiation. Reason : All metals act as black bodies.

Step-by-step solution

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 that absorbs and emits the radiation, which is treated as a black body and not even the whole container. Assertion is only partially correct.