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!

2 capacitors in series w/ a dielectric.

  1. Oct 11, 2015 #1
    • Warning: Members are reminded to use the provided Formatting Template for homework posts!
    Two capacitors (lets call them C1 and C2) in series are connected to a voltage source and charged. While still connected to the source one of them is filled with a dielectric (lets say C2 is filled). I know the charge on C2 will change by a factor of K because the source keeps the potential differences of each capacitor constant. But does the charge of the unfilled capacitor (C1) change?
    This is more of a conceptual question.

    EDIT: I got it. The charge on the unfilled capacitor remains the same.
    I would delete the thread but i can't figure out how to do that.
     
    Last edited: Oct 11, 2015
  2. jcsd
  3. Oct 11, 2015 #2

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    It doesn't, it keeps the sum of the potential differences constant.
    It does not.
    Changing the charge on one capacitor but not on the other would violate charge conservation.
     
  4. Oct 11, 2015 #3
    Hmmm.... I guess i didn't know what i thought i knew. Haha!
    So what you're saying is that the the charge on each capacitor remains the same but the potential difference of the capacitors changes; i.e.
    Vtotal=V1+V2=q/C1+q/KC2.
    So the rule for capacitors in series holds even when a dielectric is inserted into one of the capacitors?
     
  5. Oct 11, 2015 #4

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    I'm not saying that.
    They apply before and afterwards separately, sure. They'll give different results, however.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: 2 capacitors in series w/ a dielectric.
Loading...