1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    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!

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


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