Parallel rays of light of intensity I=912 Wm$^{-2}$ are incident on a spherical black body kept in surroundings of temperature 300 K . Take Stefan constant $\sigma =5.7 \times 1^{-8} Wm ^{-2} K^{-4}$ and assume that the energy exchange with the surroundings is only through radiation The final steady state temperature of the black body is close to