40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is____________________?

40% of incident radiant energy on the surface of a thermally transpare

1.	40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is____________________?
A.	0.45
B.	0.55
C.	0.40
D.	0.75
Answer» B. 0.55