# lagging current

Discussion in 'Homework Help' started by the general, Feb 16, 2011.

1. ### the general Thread Starter New Member

Feb 16, 2011
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can someone please help me understand why does current and voltage lagg and lead each other and what accounts for this mystery

Nov 25, 2009
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3. ### amilton542 Active Member

Nov 13, 2010
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its a good question what causes them to lag and leed one another? everybody knows an inductor will cause the current to lag the voltage by 90 degrees and a capacitor will cause the current to lead the voltage by 90 degrees and allaboutcircuits.com makes that clear but what are the physics for this to happen? does the voltage make its way out the other end of an inductor first instead of the current because of the reactance or what?

4. ### Adjuster Well-Known Member

Dec 26, 2010
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The voltage does not "make its way out the other end of an inductor first instead of the current because of the reactance". This is not a good picture of how circuits operate.

You can say that voltage applied across an impedance results in a current flowing. Alternatively, current can be said to to develop a potential difference across an impedance. The phase angle between current and voltage depends on the nature of the impedance.

Phase shifts result from energy storage within the inductors or capacitors, together with relationships depending on rates of change. A good textbook or the relevant articles on AAC will describe this better than I can. Note the references given by Georacer.

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