Charging a Capacitor:

The two conductor plates of the capacitor, display in Figure, are electrically neutral, because there are as several positive as negative charges on every plate. The capacitor, thus, has no charge.

Now, we connect a battery across the plates. While the switch is closed the negative charges on Plate A are attracted to the positive side of the battery, although the positive charges on Plate B are attracted to the negative side of the battery. That movement of charges will be continuing until the difference in charge among Plate A and Plate B is equivalent to the voltage of the battery. That is now a

Figure: Charging a Capacitor

"charged capacitor." Capacitors store energy as an electric field among the two plates.