Which of the following law states that “good absorbers of heat are good emitters”
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(b) Kirchhoff's law states that, the ratio of emissive power to the absorptive power corresponding to a particular wavelength and at a given temperature is constant for all bodies$:$
$e_{\lambda} / a_{\lambda}=$ constant $=E_{\lambda}$
where $E_{\lambda}=$ emissive power of a perfect black body corresponding to same wavelength and temperature, it is clear from above relation that if $a_{\lambda}$ (absorptive power) is large for a body, $e_{\lambda}$ (emissivetive power) will also be large to keep the ratio constant i.e. good absorbers are good emitters.
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