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Homework Help: Parallel RLC circuit

  1. Dec 14, 2009 #1
    1. The problem statement, all variables and given/known data

    For the following circuit:


    where R1 = 100k[tex]\Omega[/tex], R2 = 10[tex]\Omega[/tex], L = 0,1Hy, C = 200[tex]\mu[/tex]F. V gives a constant tension of 1V. Find the current I as function of the frecuence, the condition of resonance, and the condition R1 and R2 must have so that the Q factor = 0,5

    2. Relevant equations

    3. The attempt at a solution

    The problem is that I can't define de phase phi due to the lack of information about the frecuence, plus the expressions for the current I that I found are ugly.

    I condensed the resistance R1 and the inductance L into the impedance Z1 = R1 + jwL, and the resistance R2 and the capacitance C into the impedance Z2 = (1/R1 - jwC)-1. Then I condensed those two into the impedance Z3 = Z1 + Z2.

    I find this process very annoying, especially considering that I have to find the inverse of a complex number.

    What faster way can I use to solve the problem? Because if I use Kirchoff's First and Second Rule I get an uglier equation system.
  2. jcsd
  3. Dec 15, 2009 #2
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