GENERAL KNOWLEDGE

Detailed explanation-1: -According to this law, the ratio of emissive power to absorptive power is same for all surfaces at the same temperature and is equal to the emissive power of a perfectly black body at that temperature.

Detailed explanation-2: -According to Kirchhoff’s law of radiation the good heat absorbers are also good heat emitters. Thus for a given temperature the absorption coefficient of the body is equal to the emission coefficient of body.

Detailed explanation-3: -The good absorbers of heat are good – emitters of heat and are based on Kirchhoff’s radiation law. According to Kirchhoff’s law, a body strongly absorbs a radiation of certain wavelength, it must emit strongly the radiation of the same wavelength.

Detailed explanation-4: -Kirchhoff’s law of heat radiation states that the emissivity of radiating bodies is equal to their absorptivity. Kirchhoff’s law seems to remain valid in the case of nonequilibrium if induced emission is considered as negative absorption as was first shown for freely radiating weakly absorbing bodies.

Detailed explanation-5: -According to Kirchhoff’s radiation law, good heat absorbers are also good heat emitters. Hence, option C is correct.