(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

When the power factor of RLC circuit is equal to one, the frequency of the voltage source is 3 x 10^3 Hz. The rms value of the voltage source is 139 Volts and at a frequency of 3 x 10^3 Hz, the rms current in the circuit is 37.1 amps. If the inductive reactance at 3 x 10^3 Hz is 47 Ohms, what is the average power of the circuit in Watts at 0.78 times the resonant frequency of the circuit?

2. Relevant equations

Pav = Vrms Irms cos (|)

Vrms= V/sqrt 2

Irms= I/sqrt 2

V= XL I

V= Xc I

XL= 2 pi f L

Xc= 1/ 2 pi C

Res freq= 1/2pi 1/ sqrt (LC)

3. The attempt at a solution

I'm going in circles with this problem. Given the RMS value of the voltage and current, I tried to find the max voltage and current, and then plug that into V=XL I and V= Xc I to find XL and Xc, but I am probably wrong.

I guess I need to use the XL and Xc for each at the given frequency, to find both L and C to find the resonance frequency, multiply that number by .78, and then plug everything back into something?

Can someone please help me sort out this problem? Thanks

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# Homework Help: RLC Circuit- Find average power in circuit

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