Q. The wall of a pipe of radius 1 m is at a uniform temperature of 200 oC, and is covered by insulation of thickness 0.1 m. The ambient air outside the insulated pipe is at 20 oC and has heat transfer coefficient of 10 W m-2 K-1. The thermal conductivity of the insulation material is 0.05 W m-1 K-1. If the heat transfer occurs at steady state, the temperature (in oC) of the outer surface of insulation is
Ans: 27.8 to 28.6