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Homework Help: Infinite cylinder

  1. Feb 2, 2012 #1
    1. The problem statement, all variables and given/known data
    In an infinitely large evenly charged dielectric cylinder(charge density is [itex]\rho[/itex] ) there is an infinitely large cylindrical void. Prove that the electric field inside the void is homogenous and find its value. (picture)
    http://img513.imageshack.us/img513/5747/61734727.png [Broken]

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    2. Relevant equations

    3. The attempt at a solution
    I don't think i can use Gauss law here. Any ideas ?
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Feb 4, 2012 #2


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    Science Advisor
    Gold Member

    You can calculate the field at any point (radius) in a uniformly charged cylinder using Gauss's law. Now add 2 cylinders, one big and one small, of opposite charge densities to create the hole. The field within is the sum of the fields within each cylinder.
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