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General Physics

Ques.44
Ans is option 3
Plzz solve it as soon as possible
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Question image for Ques.44 Ans is option 3 Plzz solve it as soon as
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7 Years agoGrade
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Profile image of suhaas neel
7 Years ago
Hey there 
we know
 (e and E is emissivity power of an object and a black body respectively NOTE – e,a need not be 1)
Similarly a and A are absorptivity constants.
Lets take a specific case when its a black body where e become E ( as epsilon(emissivity)=1=e/E)(alpha=a/A)(epsilon and alpha for black body are 1)
and similarly a=A  ,your option 3 gives a=1 which is false, real value must be a=A ,
the real relation by kirchoff s laws give us –   e/a=E/A (see here that if you exchange E and a you get e/E=a/e
that is epsilon is equal to alpha THIS IS ONLY VIOLATED BY BLACK HOLES)