An electric cable (thermal conductivity k 125 w/m k) of radius ri 15 mm is enclosed by an insulating sleeve (thermal conductivity k,-0.18 w/m k) whose outer surface is of radius r2- 15.5mm. at the outer surface, heat transfer takes place by convection heat transfer (h-10 w/m2k) and radiation exchange (emissivity of ? = 0.9) with the adjoining air and large surroundings at a temperature of tx-25°c. when electric current passes through the cable a volumetric thermal energy is generated such that the outer surface temperature of the sleeve is measured to be 180 °c a) write the steady-state form of the heat diffusion equation for the cable and the insulation. b) solve the equations of part (a) with the boundary conditionstt and t(r)- ts2 and the condition that dt/dr 0 at the centerline of the cable c) use an energy balance at r r and at r r to find the volumetric heat generation in w/m3 and the maximum temperature in the sleeve. d) compare the amount of heat transferred in w/m by radiation and convection. account for the total energy generated and total energy dissipated.