1. Capacitors A capacitor is a device that has the ability “capacity” to store electric charge and energy.

2. Capacitors In a circuit diagram a capacitor is represented by two parallel lines of equal length

3. Capacitors

4. Figure 20-13 A Parallel-Plate Capacitor

5. Capacitors

7. A dielectric material is an insulator that increases the capacitance of a capacitor when placed between the plates. Each material has a dielectric constant  not to be confused with k.(p 665)

8. Figure 20-15 The Effect of a Dielectric on the Electric Field of a Capacitor

9. Capacitors

11. Capacitors connected in parallel have an equivalent capacity equal to the sum of the individual capacities.

12. Capacitors The charge on individual capacitors will be equal to

13. Capacitors The total charge in the circuit will be equal to

14. Capacitors Capacitors connected in series have an equivalent capacity whose reciprocal is equal to the sum of the reciprocals of the capacities of the individual capacitors.

15. Capacitors

16. Capacitors connected in series all have the same charge Q

17. Figure 21-17 Capacitors in Series

18. Capacitors Voltage drops across capacitors connected in a series

19. Capacitors Voltage drops across capacitors connected in a series

20. Capacitors Capacitors connected in parallel have an equivalent capacitance which is equal to the sum of the capacitances of the individual capacitors.

21. Figure 21-16 Capacitors in Parallel

22. Capacitors

23. Charges on capacitors connected in parallel are calculated by multiplying the voltage drop by individual capacitances.

24. Capacitors

25. Figure 21-16 Capacitors in Parallel

26. Example 21-8 Energy in Parallel

27. Figure 21-17 Capacitors in Series

28. Active Example 21-3 Find the Equivalent Capacitance and the Stored Energy

29. Figure 21-18 A Typical RC Circuit

30. Figure 21-19 Charge Versus Time for an RC Circuit

31. Figure 21-20 Current Versus Time in an RC Circuit

32. Example 21-9 Charging a Capacitor

33. Figure 21-21 Discharging a Capacitor

34. Figure 21-39 Problems 21-53 and 21-55

35. Figure 21-43 Problems 21-67 and 21-87

36. Figure 21-45 Problem 21-78

37. Capacitors Solve problems 53-58 on pages 711 and 712.