Electric current

 An initially uncharged capacitor C is fully charged by a constant emf e in series with a resistor R as shown in Fig. 31-20 above. (a) Show that the final energy stored in the capacitor is half the energy supplied by the emf. (b) By direct integration of i2R over the charging time, show that the internal energy dissipated by the resistor is also have the energy supplied by the emf.

At what time after charging begins is the rate of energy dissipation in the resistor equal to the rate of energy storage in the capacitor?