I just finished an exam and this problem gave me fits. It seemed simple enough when I first looked at it, but it took me a while to come to the following conclusions which I'm not sure are correct.(adsbygoogle = window.adsbygoogle || []).push({});

The problem had an RLC series circuit with source of 141.4 Volts peak and a frequence of 1 kHz. The RMS voltage over the inductor is 100 volts and the RMS voltage over the capacitor is 40 volts.

I needed to find the RMS voltage over the resistor, the power factor and draw a phasor diagram of the voltages.

This is my reasoning and boy do I hope it's correct:

Since it's a series circuit the current is the same through all the components. Therefore, can't I use a phasor diagram to find Vrms over the resistor.

The voltage of the inductor would have a phase angle of 90 degrees and the voltage of the capacitor would have a phase angle of -90 degrees, so on the y-axis (complex axis) I'd have a vector 60 volts long and on the x-axis (real axis) I'd have the 100 rms volts from the source or would I have the unknown Vrms of the resistor?

Argh! I put the 100 volts rms for the source on the x-axis, but now I'm thinking it should have been the unknown Vrms over the resistor.

Too tired to think about out it right now, but I'd really appreciate some input.

Thanks

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# RLC Series Circuit

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