A 2 2 mm diameter and 10 m long electric wire is tightly wrapped with a 1 mm thick plastic cover whose thermal conductivity is k 0 15 W m middot K Electrical measurements indicate that a current of 13 A passes through the wire and there is a voltage drop of 8 V along the wire If the insulated wire ...

An electric wire is tightly wrapped with a 1mm thick plastic cover The interface temperature and the ...

A 2.2-mm-diameter and 10-m-long electric wire is tightly wrapped with a 1-mm-thick plastic cover whose thermal conductivity

Question:

A 2.2-mm-diameter and 10-m-long electric wire is tightly wrapped with a 1-mm-thick plastic cover whose thermal conductivity is k = 0.15 W/m·K. Electrical measurements indicate that a current of 13 A passes through the wire and there is a voltage drop of 8 V along the wire. If the insulated wire is exposed to a medium at T_ˆž= 30°C with a heat transfer coefficient of h = 24 W/m²·K, determine the temperature at the interface of the wire and the plastic cover in steady operation. Also determine if doubling the thickness of the plastic cover will increase or decrease this interface temperature.

Electrical wire T = 30°C - Insulation -10 m