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Capacitor Help

  1. Dec 17, 2009 #1
    1. The problem statement, all variables and given/known data
    A fully charged 10e-4 F capacitor has a potential difference across it of 9Volts. It is then connected to a resistor of 10 ohms. How long will it take for the current through the resistor to decrease to 1/2 of its initial value?

    2. Relevant equations

    3. The attempt at a solution
    I know the answer is 6.9e-4 secs... but I want to know how it was done :/ Anyone?
  2. jcsd
  3. Dec 17, 2009 #2


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    Homework Helper

    What formulas do you know (or can you look up) that involve a circuit with a resistor and a capacitor?
  4. Dec 17, 2009 #3
    Well I have..
    V = IR
    I = |q|nAv
    v = uE

    R = L |q|nAu
  5. Dec 17, 2009 #4
    Last edited by a moderator: Apr 24, 2017
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