Capacitor

Q : How do capacitors store a charge?

Answer: Capacitors act like tiny storage batteries made of two plates separated by a thin insulator or air. When one plate is charged negative and the other positive, they build up a charge that remains when the current is removed. When its power is required, the circuit is switched to conduct current between the two plates, and the capacitor releases its charge. AnswerCapacitors don't really store charge at all. They allow negative charge to be transferred from one plate to the other, thus establishing an electric field between their plates. But there is no net increase in charge -the amount of charge on the capacitor's plates, after 'charging', is exactly the same as there was before 'charging' -it's just moved around! What capacitors 'store' is energy, not charge.