1. Capacitors

2. Charging a Capacitor

3. Charging a Capacitor

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

5. 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.

6. Dielectrics and Capacitors

7. Dielectrics and Capacitors

8. 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:

9. 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.