A black body of total area $45c{m}^2$ is exposed in a space surrounded by $0\mathrm{.}05m$ thick walls. The

walls have a surface area of $5m^2$ and thermal conductivity $1\frac{W}{m}K.$ If the inner surface of the wall

is maintained at at $215C$ and the outer wall surface at $30C,$ calculate the temperature of the

black body. Stefan$-$Boltzmann's

constant $=5\mathrm{.}6710-8(\frac{W}{m^2}{K}^4)$