Question

A spherical body of area A and emissivity e = 0.6 is kept inside a perfectly black body. Energy radiated per second by the body at temperature T is ___________

(a) 0.4σAT^4

(b) 0.8 σAT^4

(c) 0.6 σAT^4

(d) 1.0 σAT^4

Answer 1

Correct choice is (c) 0.6 σAT^4

For explanation: According to Stefan’s law, energy radiated per second by a body of emissivity e at a temperature T,

E = e σAT^4

E = 0.6 σAT^4.