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Homework Help: Equivalent capacitance

  1. Nov 19, 2006 #1

    The "C"s stand for capacitor.
    The capacitance of C2 is 10 μF and others are 4 μF.

    The book contains neither the answer nor solution.

    I tried to apply Kirchhoff's Loop Rule:
    q_4 / 4 + q_2 /10 + q_3 / 4 = 0
    q_1 / 4 + q_2 /10 + q_5 / 4 = 0
    q_1 + q_4 + q_3 + q_5 = 0

    Then I got the equivalent capacitance=0. What is the problem with my argument?
  2. jcsd
  3. Nov 19, 2006 #2


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    Science Advisor
    Homework Helper

    My guess is you have a sign problem. It's not obvious to me that you have assumed one sign for the voltage drop across each capacitor and used it consistently. In fact, it looks very much like you have not. There must be some additional equations based on charge conservation.
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