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Difference Between Thin and Conductive charge configurations

  1. Mar 13, 2014 #1
    Difference Between "Thin" and "Conductive" charge configurations

    Is there any difference computationally between say a thin spherical insulating shell and a thin conductive shell ?

    Can you create a capacitor with two thin insulating shells, one smaller than the other ?

    I see most textbooks explicitly say that capacitors must be conductors. Is this so ?
     
  2. jcsd
  3. Mar 13, 2014 #2

    UltrafastPED

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    The charge enters the capacitor from outside - with an insulator the incoming charge is stuck in one spot, so it would make a lousy capacitor. With conducting surfaces source charges can flow so that the entire surface is charged (both plates/spheres).

    The region between the conductors is the insulator; the charges on the plates induce small movements in the molecules of the conductor - they "polarize" the material, but no charge moves more than a few nanometers.
     
  4. Mar 13, 2014 #3
    Say a charge is already uniformly distributed on the thin spheres. Can you talk about capacitance then ? I realize that it is the practicality of charging that is the problem, but textbooks talk about uniform charge on insulators all the time.
     
  5. Mar 15, 2014 #4

    UltrafastPED

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