6. An electrical cable of radius 5mm is designed to carry an electrical current such that the heating effect is 300 W pe
Posted: Mon May 02, 2022 3:35 pm
6. An electrical cable of radius 5mm is designed to carry an electrical current such that the heating effect is 300 W per metre length. The cable is in an environment having a temperature of 25°C. The heat transfer coefficient between the cable and the environment is 25 W/m²K. A very thin coating of electrical insulation is applied to the cable, with a contact resistance equivalent to 0.02 m K/W. (a) What are the electrical insulation and cable surface temperatures? (b) What effect does the electrical insulation have on the cable temperature? (Ans = 789°C, 1171°C; 789°C)