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Electric field across a parallel plate capacitor

  1. Mar 22, 2009 #1
    Hello,

    If I had a potential source (V) , a resistor R, and a parallel plate capacitor,

    would the Electric field across the capacitor become

    E = (V - IR)/L

    L = distance between capacitor

    or would the electric field simply become E = V/L

    ??

    thank you!!
     
  2. jcsd
  3. Mar 22, 2009 #2

    Delphi51

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    How is the circuit set up? Your E = (V - IR)/L would be correct for a purely series circuit. But the current would be zero (or quickly become zero as the capacitor charges) so your second formula is then correct.
     
  4. Mar 22, 2009 #3

    LowlyPion

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    That very much depends on whether the resistor is in series or in || with the capacitor doesn't it?
     
  5. Mar 26, 2009 #4
    Ah ic, oh okay I understand now.

    so if in series,
    clearly initially it is

    E = (V-IR) /L
    but after the capcitor is fully charged then E = V/L

    however if in parallel from the start then

    E = V/L, always

    would this be correct?
     
  6. Mar 26, 2009 #5

    Delphi51

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    If the V, R and C are all in parallel then they all have the same potential V.
     
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