Question 1).

A 1/8" diameter copper wire is covered with 1/16" thick insulation (k = 0.21 Btu/hr-ft- oF). Air blows in crossflow over the wire at 19 ft/s. The wire carries a current of 300 A and the air is at 80oF. The electrical resistivity of copper is 6.77 x 10-7?-in. Where is the insulationtemperature greatest? Determine this temperature. (NOTE: You will need to use a thermalresistance network to represent the heat transfer through the insulation into the surrounding air.)

Question 2)

The walls of a house are constructed of an exterior sheathing, insulation, framingtimber, and drywall. The composite resistance of the materials is 4.15 m2-K/W. On a winter daywhen the outdoor temperature is -5oC, wind blows at 30 km/hr parallel to the 3 m high, 18 m longwall. If the convection coefficient on the interior side of the wall is 5 W/m2-K and the interiortemperature is 21oC, determine the rate of heat loss through the wall