Consider an uninsulated wire with a diameter of 1 mm generates electrical heating at the rate of 2 W/m^2 when it hangs in air. The temperature difference between the wire and the ambient air is 25°C. To cover the wire with an electrical insulation, the thermal engineers consider using a plastic sleeve with an outer diameter of 2 mm and the thermal conductivity of 0.15 W/m.°C.
1) Will the electrical insulation of the plastic sleeve act as a thermal insulation as well?
2) When the wire is wrapped by the plastic sleeve, what will be the temperature difference between the wire and the ambient air?