A hollow spherical container of negligible thickness is subjected to uniform heat rate of 30 W from the inside surface, while the outside surface is subjected to convection and radiation heat transfer. The sphere has an outer diameter of 0.4 m insulated with three layers each 50 mm thick insulation of k, = 0.02: k, = 0.06 and ka = 0.1 W /mK. (Starting from inside). The outside room temperature is 20C and h = 25 W /m?. K and the emissivitye = 0.5. Determined the inside temperature of the sphere as well as the Interface temperatures of insulating layers. [20]