This document discusses key concepts about capacitors including: 1) A capacitor is made of two conductors separated by an insulator. It can store an electric charge and energy. 2) The capacitance of a capacitor depends on the geometry of the conductors and the dielectric material between them. It measures how much charge is stored for a given potential difference. 3) The energy stored in a capacitor depends on the charge and capacitance. Adding a dielectric increases the capacitance and stored energy.

1. 25-2. Capacitance charge storage, energy storage Given As a Result Capacitor: Any two isolated conductors

2. 25-2. Capacitance Units of capacitance: Farad (F) = Coulomb/Volt Potential (or Voltage) Capacitance

3. 25-2. Capacitance +q -q E field between the plates: (Gauss’ Law) Relate E to potential difference V : What is the capacitance C ? Area of each plate = A Separation = d charge/area =  = q/A

4. 25-2. Capacitance Capacitance and Your iPod

8. 25-3. Calculating the Capacitance Cylindrical Capacitor

9. 25-3. Calculating the Capacitance Spherical Capacitor

10. 25-3. Calculating the Capacitance Capacitance of a single conducting sphere Spherical Capacitor

11. 25-4. C in Parallel and in Series Q: the same V: the same Parallel Series

17. 25-4. Example 4 (N-1) Capacitors with A and d: Parallel Connection + –

22. 25-6. Capacitor with a Dielectric Dielectric: Noncoducting material HW5-8 Breakdown Potential: Dielectric Strength (kV/mm) X Length (mm)

23. 25-6. Capacitor with a Dielectric or ??

24. 25-6. Capacitor with a Dielectric

25. 25-6. Capacitor with a Dielectric