Consider a slab-shaped graphite electrode that is 3 ft long, 3 in.

wide, and 0.5 in. thick. A voltage difference of 24 V is applied across the 3-

ft length. Assuming that the temperature is uniform over the 3-ft length and the 3-in. width, plot the temperature profile along the 0.5-in. thickness and determine the temperature at the center of the electrode if the surface temperature of the electrode is 176°F on both sides. Assume that the temperature in the electrode is only a function of the coordinate along the 0.5-in.-thick dimension of the slab. What would the external heat transfer coefficient have to be in order to have the surface temperature of 176°F if the external ambient temperature is 68°F? How would your answer change if the slab is insulated on one side and the surface temperature is 176°F on the un-insulated side? The thermal conductivity of the graphite used is 2.9 BTU/h ft °F and its electrical resistivity is 1.4 × 10-4 Ω ⋅ ft.