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A surface has emissive power 2.4 xx 10^(...

A surface has emissive power `2.4 xx 10^(-2) watt/m^2` and perfectly black surface has emissive power of `3 xx 10^(-2) watt/m^2` . The emissivity of the surface is

A

a)0.8

B

b)0.6

C

c)0.9

D

d)0.5

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The correct Answer is:
A
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