a.c.+circuit question

2011-04-09 5:24 am

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The answer is option A.
Why must the voltage accross the bulb B1 will not be affected when a.c. current is used?

更新1:

天同: An error made. I want to ask again.. Why must the voltage accross the bulb B1 not be affected by the inductor when a.c. current is used?

回答 (1)

天同

2011-04-09 7:18 am

✔ 最佳答案

Bulb B1 is connected in series with a resistor. The resistance of which is independent of frequency. Hence, disregard a dc or ac is used as the source, the resistance is the same. Thus the current and the bulb brightness remain unchanged.

2011-04-08 23:19:53 補充：
Also, a 12v rms voltage source delivers the same power as a 12v dc does.

2011-04-09 14:38:38 補充：
Your supplementary queston:
The two branches with bulbs B1 and B2 are connected in parallel with the ac source. The voltage of each branch is thus determined only by the source voltage.

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