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B Excess charge on insulators and conductors

  1. Jan 3, 2017 #1
    From what ive learned, excess charge on an insulator stays where it is but excess charge on a conductor spreads uniformly throughout its surface. Why does this happen? Can this be explained in terms of electrostatic potential?
     
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  3. Jan 3, 2017 #2

    ZapperZ

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    Sure! Under static condition, what is the electric field inside an idealized conductor?

    Zz.
     
  4. Jan 3, 2017 #3
    I mean, why doesnt it stay in one place like in an insulator?
     
  5. Jan 3, 2017 #4

    ZapperZ

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    Do you know what makes a conductor a conductor, and an insulator and insulator? The amount of mobile charges in it! Insulators do not have any (or many) mobile electrons (or holes), while a conductor/metal, by definition has these things called "conduction electrons" which can move around very easily and are not tied to any particular sites in the conductor.

    When there are mobile charges, they tend to move as far away from one another as possible, AND, they tend to follow where there are, if any, electric fields. It is why I asked if you know what is the electric field inside a conductor under static condition.

    Zz.
     
  6. Jan 3, 2017 #5
    I see. Thanks.
     
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