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Homework Help: Charge and potential differnecr in a mixed circuit

  1. Jul 12, 2008 #1
    1. The problem statement, all variables and given/known data
    a potential difference V = 100 V is applied across a capacitor arrangement with capacitances C1 = 11.0 µF, C2 = 7.00 µF, and C3 = 3.00 µF. Find the following values Charge on each capacitor, potential difference on each capacitor, and stored energy in Joules.

    The circuit is set up with battery and then a mixed series and parallel. C1 and C2 are in a series on a branch and C3 is on a separate branch in parallel with both C1 and C2.

    2. Relevant equations
    In a series I find charge with (1/c1 + 1/c2) = q/v looking for q. I plugged in (1/11 + 1/7) = q/100. SOlved and got a charge of 23.4 microCoulombs each on C1 and C2.

    So now I am stuck I thought I solved the series first and then used that combine capacitance to find the charge on C3. Help
    Last edited: Jul 12, 2008
  2. jcsd
  3. Jul 12, 2008 #2


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    Homework Helper

    I would suggest finding the equivalent capacitance of all of them before applying voltage.

    As I read your problem you have C1 and C2 in series with each other but taken together in parallel with C3. With the value of the effective capacitance you can calculate total stored charge in the system. Then maybe work backwards splitting the charge between the two branches could give you some insight?
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