An electric wire of 2 mm diameter is given a 25 mm thick insulation (k = 0.5 W/m°C). The surroundings has temperature of 25°C and heat transfer coefficient h = 10 W/ m2°C. The wire has surface...

An electric wire of 2 mm diameter is given a 25 mm thick insulation (k = 0.5 W/m°C). The surroundings has temperature of 25°C and heat transfer coefficient h = 10 W/ m2°C. The wire has surface temperature of 120°C. Compare the heat dissipation with and without insulation. Find the thickness of insulation when heat dissipation is maximum and find its value.