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Bound and Free Charge in conductor and dielectric

  1. Nov 20, 2008 #1
    I am reading an electrodynamics book to grasp the concept of bound and free charge, esp in conductor and dielectric. I got lost with the text on the book. Can anyone please help me understand the concept well?
  2. jcsd
  3. Nov 20, 2008 #2


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    Staff: Mentor

    I bet some people here could help... what specific questions do you have?
  4. Nov 20, 2008 #3


    Staff: Mentor

    A free charge can move in response to an externally supplied force while a bound charge cannot.
  5. Nov 20, 2008 #4


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    Free charges are free to move about the entire medium, while bound charges are restricted to moving in small 'loops' around whichever molecule/ atom they are bound to.
  6. Nov 20, 2008 #5


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    For a bit more detail, click free charge for the PF Library item :smile:
  7. Nov 21, 2008 #6

    in case of a wire carrying a certain amount of charge, say Q, which is insulated by a insulator (dielectric), I read that the bound charge on the outer surface and inner surface of the insulator is equal to each other in magnitude. But I could not derive it myself. My approach was to use Guass's law for D, but i did not get what enclosed free charge was. In such a case, how does the equation [tex]\rho[/tex] = [tex]\rho[/tex]b + [tex]\rho[/tex]f hold true?
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