1. Electromagnetic Oscillations and Alternating Current
Chapter 31
Electromagnetic Oscillations and Alternating Current
In this chapter we will cover the following topics:
-Electromagnetic oscillations in an LC circuit Alternating current (AC) circuits with capacitors Resonance in RCL circuits Power in AC circuits Transformers, AC power transmission
(31-1)

2. L C
(31-2)

3. L C
(31-3)

4. L C
(31-4)

5. 1 2 3 4 5 6 7 8
(31-5)

6. (31-6)

7. (31-7)

8. (31-8)

10. L C
(31-9)

11. (31-10)

12. (31-11)

13. (31-12)

14. O
(31-13)

15. (31-14)

16. O
(31-15)

17. (31-16)

18. SUMMARY Circuit Element Average Power Reactance Phase of Current
Voltage Amplitude
Resistor R
Current is in phase with the voltage
Capacitor C
Current leads voltage by a quarter of a period
Inductor L
Current lags behind voltage by a quarter of a period
(31-17)

19. (31-18)

20. O A B
(31-19)

21. O A B
(31-20)

22. (31-21)

23. (31-22)

24. (31-23)

25. (31-24) Transmission lines Erms =735 kV , I rms = 500 A Home
Power Station
Transmission lines Erms =735 kV , I rms = 500 A
Home
110 V T1 T2
Step-up transformer
Step-down transformer
R = 220Ω
(31-24)

26. (31-25)

27. (31-26)

28. (31-27)