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!

Homework Help: Discharging capacitors

  1. Mar 9, 2017 #1

    Kajan thana

    User Avatar
    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


    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


    User Avatar
    Homework Helper

    The discharge is 99% complete when the charge or voltage on the capacitor is 1% of the initial value.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted