What is a black body ?

The rate of dissipation of heat by a black body at temperature T is Q . What will be the the rate of dissipation of heat by another body at temperature 2T and emissivity 0.25 ?

If the radius of a star is R and it acts as a black body, what would b the temperature of the star, in which the rate of energy production is Q ?

If the radius of a star is R and it acts as a black body, what would b the temperature of the star, in which the rate of energy production is Q ?

The temperature at which a black body of unit area loses its energy at the rate of 1 joule/second is

The energy radiated by a black body is directly proportional to :

Which of the following is close to an ideal black body ?

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

A card is drawn from a pack of 52 cards. What is probability that is a black king?

Will a black body appear black at any temperature ? If so when ?

A: The reflectance of a black body is zero. R: Black body absorbs all radiations incident on it.