Question

The energy delivered to the resistive coil is dissipated as heat at a rate equal to the power input of the circuit. However, not all of the energy in the circuit is dissipated by the coil. Because the emf source has internal resistance, energy is also dissipated by the battery as heat. Calculate the rate of dissipation of energy pbat in the battery.

Answer 1

The rate of energy dissipation in the internal resistance will be V/(R+r)^2 * r

Explanation:

Let R be the resistance connected in the circuit, r the internal resistance of the battery and V the voltage of battery. Hence,

Total resistance = R + r

Current = I = V/(R+r)

Now,

Rate of energy dissipated in internal resistance of battery = Pbat = I^2 * r

Rate of energy dissipated in internal resistance of battery = Pbat = (V/R+r)^2 * r