An ideal Black-body at room temperature is thrown into a furnace. It is observed that

Options

A. initially it is the darkest body and at later times the brightest
B. it is the darkest body at all times
C. it cannot be distinguished at all times
D. initially it is the darkest body and at later times it cannot be distinguished

Answer

D

Explanation

Black body radiates maximum number of wavelength and maximum energy if all other conditions (e.g., temperature surface area etc.) are same. So , when the temperature of black body becomes equal to the temperature of the furance , the black body will , radiate, maximum energy and it will be brighted of all. Initially it will absorb all the radiant energy incidenton it, so is the darkest one.