A black body A at a temperature of `527^(@)C`, emits radiant energy at the rate of 16 watt. Another black body B at temperature `127^(@)C`, emits radiant energy at the rate 8 watt in the same surrounding. Compare the surface areas of A and B.

Explanation

For an opaque body , t= 0
Also a =e= 0.9
a+r+t=1
0.9 +r+ 0 =1 r= 1 - 0.9 = 0.1
Total radiant heat (Q) incident on the body in 1 minture is
` Q = ((dQ)/(dt)) xx "time" = 100 xx 60 = 6000 J`
The quantity of radiant heat reflected (`Q_(r))` by the body in 1 minute is
` Q_(r) = rQ = 0.1 xx 6000 = 600 J`