Capacitors

Charging a Capacitor

Charging a Capacitor

Charging a Capacitor A capacitor can be used to store charge.

The Parallel-Plate Capacitor A parallel-plate capacitor is important because it creates a uniform electric field between its flat electrodes. The electric field of a parallel- plate capacitor is A is the surface area of the electrodes, and Q is the charge on the capacitor.

Dielectrics and Capacitors

Dielectrics and Capacitors

Since, Q = CΔVC, the potential energy can be written: Energy and Capacitors A charged capacitor stores energy as electric potential energy. The potential energy UC stored in a charged capacitor is Since, Q = CΔVC, the potential energy can be written:

Energy and Capacitors A capacitor can charge very slowly and then can release the energy very quickly. A medical application of this ability to rapidly deliver energy is the defibrillator. Fibrillation is the state in which the heart muscles twitch and cannot pump blood. A defibrillator is a large capacitor that can store up to 360 J of energy and release it in 2 milliseconds. The large shock can sometimes stop fibrillation.