A spherical shaped vessel of 1.4 m outer diameter is 90 mm thick. Find the rate of heat leakage, if the temperature difference between the inner and outer surfaces is $$220^\circ C$$. Thermal conductivity of the material of the sphere is 0.083 W/m K.

A

0.2 kW

B

0.5 kW

C

1.088 kW

D

1.6 kW