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Homework Help: Discharging capacitors

  1. Mar 9, 2017 #1

    Kajan thana

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    Gold Member

    1. The problem statement, all variables and given/known data
    .50uf capacitor is charged connecting it to a 6.0v battery then discharged through 100k ohm resistor.
    . Question: Estimate the resistance of the resistor that you would use in place of the 100k ohm resistor if the discharge is to be 99% completed within about 5 secs.

    2. Relevant equations

    cf8fbc5ea72dc057fbc63976e4083353.png

    3. The attempt at a solution
    I used voltage instead of charge.

    99% of 6V in 5.94V which is discharged in 5 seconds.

    5.94/6= e^-5/CR

    Then make the R the subject gave 995x10^5 ohm. The answer is wrong, help me please.
     
  2. jcsd
  3. Mar 9, 2017 #2

    ehild

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    Homework Helper

    The discharge is 99% complete when the charge or voltage on the capacitor is 1% of the initial value.
     
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