A long homogeneous resistance wire of radius r0 = 5 mm is being used to heat the air in a...

A long homogeneous resistance wire of radius r0 = 5 mm is being used to heat the air in a room by the passage of electric current. Heat is generated in the wire uniformly at a rate of 5 × 107 W/m3 as a result of resistance heating. If the temperature of the outer surface of the wire remains at 180°C. determine the temperature at r = 3.5 mm after steady Operation conditions are reached. Take the thermal conductivity of the wire to be k = 6 W/m K. Answer: 207°C