1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

RLC Circuit (with variable frequency!)

  1. Jan 5, 2010 #1
    1. The problem statement, all variables and given/known data

    Find the frequency at which the circuit becomes purely resistive and calculate the effective resistance.

    Here is the circuit with the given solution-


    The trouble is, whilst the solution is simple enough, there are many places to go wrong, and the whole process is time comsuming. I've managed to simplify a few other answers given in this answer booklet, but for this one, i can't find an easier method.

    Any ideas? I can't find a similar example in Hughes.

  2. jcsd
  3. Jan 5, 2010 #2


    User Avatar
    Homework Helper

    If Z is real so is 1/Z.

    [tex]\frac{1}{Z}=\frac{R-j\omega L}{R^2+(\omega L)^2}+j\omega C=\frac{R}{R^2+(\omega L)^2}+j\omega( C-\frac{ L}{R^2+(\omega L)^2})[/tex]

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook