"Good reflectors are poor emitters of thermal radiation." explain.

Explanation

Let r and a be the reflecting power and absorbing power respectively of a body. If a body does not transmit any thermal radiation, then its transmitting power t is zero. Since ltbr. `r+a+t = 1 , so r+a=1 or a=1-r`
Clearly, if r is more, a is less and vice versa, i.e., good reflectors are bad absorbeds.
Ac cording to Kirchhoff's law if a body absorbs certains radiations when exposed by the radiations from a source at higher temperature, it must emit same radiations, when left free. as good reflector is a bad absorber so it is a bad emitter. hence, good reflectors are poor emitters of thermal radiations.