What Is the Frequency of the Voltage Source in an LRC Series AC Circuit?

[Fisicks]

Homework Statement

An ac voltage source is connected in series with a 1 uF capacitor and a 750 ohm resistor. The amplitude of the voltage source is measured to be 4V rms while the voltages across the resistor and across the capacitor are 3V rms and 2.7V rms respectively. Determine the frequency of the voltage source.

Homework Equations

The Attempt at a Solution

I said that the current going through the resistor is 250, and then Z=(750^2 + (1/wC)^2)^1/2. So i let 4/250=Z but this isn't right, where am i going wrong?

Thanks guys

 

[cepheid]

This is just an RC circuit (no inductor). Anyway, one the problems I can see with your calculations is that if

V_R = IZ_R = IR,

Then I = V_R/R = 3 V_rms / 750 ohm = 4 mA_rms

not 250 A.

 

[Fisicks]

Ok, so I would do 4/(4x10^-3)=Z then?

 

[cepheid]

Ok, so I would do 4/(4x10^-3)=Z then?

It should work. Did you try it? Based on your first post, it seems like you know what the correct answer is supposed to be.