# B Voltage across R, L and C vs AC Voltage source in RLC Series Circuit

#### Zahid Iftikhar

Summary
In RLC series circuit, the voltage across circuit elements may be higher than the source voltage, which is contrary to DC series circuit.
One property of series resonance circuit is that at resonance, the voltage across circuit elements R,L and C may be larger than the source voltage. I can relate it to vector analogy where component vectors may have larger values than the resultant and the phenomenon is counter-intuitive. This does not happen in DC circuits where sum of voltage across circuit components is always equal to the source voltage. Any useful intuitive explanation of this effect please?

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#### berkeman

Mentor
A useful analogy for resonant excitation is to think about a swinging weight on the end of a rope, and you pushing it at the extreme of each swing with a small force and displacement with your fingertip.

As long as the losses are low for the swinging weight, it takes very small repetitive/resonant forces and small pushes from your fingertip to make it build up a large swing displacement -- much larger than the small periodic push amplitude of your fingertip...

#### vanhees71

Gold Member
It's simply sloppy! Don't use such sloppy books! There's no voltage across an inductance, it's an EMF. In time-varying magnetic fields, there's no potential for the elctric field due to Faraday's Law, which is one of the fundamental Maxwell equations,
$$\vec{\nabla} \times \vec{E}=-\frac{1}{c} \partial_t \vec{B}.$$

#### Zahid Iftikhar

It's simply sloppy! Don't use such sloppy books! There's no voltage across an inductance, it's an EMF. In time-varying magnetic fields, there's no potential for the elctric field due to Faraday's Law, which is one of the fundamental Maxwell equations,
$$\vec{\nabla} \times \vec{E}=-\frac{1}{c} \partial_t \vec{B}.$$
Thanks. I need more help on this please.

#### vanhees71

Gold Member

"Voltage across R, L and C vs AC Voltage source in RLC Series Circuit"

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