1. Circuit element Average Power ReactancePhase of currentVoltage 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 SUMMARY (31 - 17)

2. (31 - 18)

3. O A B (31 - 19)

4. O A B (31 - 20)

5. (31 - 21)

6. (31 - 22)

7. (31 - 23)

8. Power Station Transmission lines E rms =735 kV, I rms = 500 A home 110 V T1T1 T2T2 Step-up transformer Step-down transformer R = 220Ω (31 - 24)

9. (31 - 25)

10. (31 - 26)

11. (31 - 27)

12. Hitt A generator supplies 100 V to the primary coil of a transformer. The primary has 50 turns and the secondary has 500 turns. The secondary voltage is: A. 1000 V B. 500 V C. 250 V D. 100 V E. 10V

13. hitt The main reason that alternating current replaced direct current for general use is: A. ac generators do not need slip rings B. ac voltages may be conveniently transformed C. electric clocks do not work on dc D. a given ac current does not heat a power line as much as the same dc current E. ac minimizes magnetic effects