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

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