Passage of an electric current through a long conducting rod of radius ri and thermal conductivity kr results in uniform volumetric heating at a rate of q. The conducting rod is wrapped in an electrically non conducting cladding material of outer radius r0 and thermal conductivity kc, and convection cooling is provided by an adjoining fluid. For steady-state conditions, write appropriate forms of the heat equations for the rod and cladding. (Start with the thermal energy balance and derive the heat conduction equation.) Express boundary conditions for the solution of these equations.