Heat TransferHard
Question
Two electric lamps A and B radiate the same power. Their filaments have the same dimensions and have emissivities eA and eB. Their surface temperatures are TA and TB The ratio 
will be equal to :-
will be equal to :-Options
A.
B.
C.
D.
Solution
The power radiated by a filament is P = e(σT4) (area), where e = emissivity, σ = Stefan′s constant, T = surface temperature. Here, eT 4 = constant or
eATA4 = eBTB4
eATA4 = eBTB4
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