# A metal ball having surface area of $\;2 \times 10^{-2}\;m^2\;$ and at 900 K is kept in an enclosure at 300 K . If the surface emissivity of metal is 0.4 , find the rate of which heat is lost by the ball
$(a)\;293\;W\qquad(b)\;193\;W\qquad(c)\;173\;W\qquad(d)\;483\;W$