An electrical wire of radius R, electrical conductivity ke ohm-1 cm-1 , is carrying current with a density of I amp/cm2 . The transmission of current is considered to be an irreversible process, and some electrical energy is converted into thermal energy. The rate of thermal energy production per unit volume (Se) is given by e k I 2 . Assume that the temperature rise in the wire is not so large that the temperature dependence of either the thermal or electrical conductivity need be considered and Se is a constant. Write down the postulates for this case and determine the temperature distribution in the wire using the equation of energy (Appendix B.9) as a starting point. Assume steady state conditions. The surface of the wire is maintained at temperature T0.