Assertion : A body that is a good radiator is | vedclass

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(A) According to Kirchhoff's law of radiation,for an arbitrary body,the ratio of its emissive power $(e_{\lambda})$ to its absorptivity $(a_{\lambda})

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If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

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(A) According to Kirchhoff's law of radiation,for an arbitrary body,the ratio of its emissive power $(e_{\lambda})$ to its absorptivity $(a_{\lambda})$ at a given wavelength and temperature is equal to the emissive power $(E_{\lambda})$ of a perfectly black body at the same wavelength and temperature.Mathematically,$\frac{e_{\lambda}}{a_{\lambda}} = E_{\lambda}$.Since $E_{\lambda}$ is a constant for a given wavelength and temperature,it follows that $e_{\lambda} \propto a_{\lambda}$.This implies that a body with high emissivity (good radiator) must also have high absorptivity (good absorber) at that specific wavelength. Thus,both the Assertion and the Reason are correct,and the Reason is the correct explanation of the Assertion.

$Assertion :$ $A$ body that is a good radiator is also a good absorber of radiation at a given wavelength.
$Reason :$ According to Kirchhoff's law,the absorptivity of a body is equal to its emissivity at a given wavelength.

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$Assertion :$ $A$ body that is a good radiator is also a good absorber of radiation at a given wavelength.$Reason :$ According to Kirchhoff's law,the absorptivity of a body is equal to its emissivity at a given wavelength.