# Homework Help: Fit P(w) to determine Q,w, and R (Series RLC AC circuit)

1. May 3, 2010

### PhysicsMark

1. The problem statement, all variables and given/known data

Fit P(w) to determine Q, and w_0, and R. You should put in Vrms as a known constant.

2. Relevant equations

$$P(\omega)={\frac{V_{rms}^{2}}{R(1+Q^2(\frac{\omega}{\omega_0}-\frac{\omega_0}{\omega})^2)}$$

$$Q=\frac{\omega_0}{\Delta\omega}$$

$$R=R_load+r$$

3. The attempt at a solution

I have 14 data points. They are Vrms over the resistor for a range of 1350-2000Hz in increments of 50Hz.

R_load is the resistance of the resistor. r is the unknown resistance in the inductor.

I am not sure what this question is asking here. In this lab, we took measurements of the Vrms as described above using known values for R_load, L, C, and V_in_rms. The question before this has me plot P(w), mark the FWHM (full width half max) and determine Q from the plot.
I know part of point of this lab is to determine unknown values of the circuit using different methods and compare with theory.

I first thought it was asking me to plot P(w) again, but this doesn't make sense. The first plot is terrible since it is dependent on the graphing software (excel) for the curve (so few points).

Does anyone have interpretations of what it is asking here?