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Nonconducting surface uniform charge hole

  1. Oct 14, 2010 #1
    1. The problem statement, all variables and given/known data
    Didn't know what to put for thread title, my notes and textbook were a little to ambiguous

    A large, flat, nonconducting surface carries a uniform charge density σ. Into the middle of this sheet has been cut a small, circular hole of radius R. Ignoring fringing fields from the edges, calculate the electric field at a point, P that is a distance z from the center of the hole along its axis. hint: consider the electric field from a sheet of charge and the electric field from a disk of charge



    edit** nevermind i was being dumb, i got it
     
    Last edited: Oct 15, 2010
  2. jcsd
  3. Oct 16, 2010 #2

    rl.bhat

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    Homework Helper

    You can consider the large, flat, nonconducting surface carries a uniform charge density +σ

    and the hole as a disc carrying a uniform charge density -σ.

    The electric field due to the surface is

    [tex]E_1 = \frac{+\sigma}{2\epsilon_{0}}[/tex]

    The electric field due to the disc is

    [tex]E_2 = \frac{-\sigma}{2\epsilon_{0}}(1 - \frac{z}{\sqrt{z^2 + r^2}})[/tex]

    Now find the net field at P.
     
  4. Oct 16, 2010 #3
    that is exactly how i did it. thanks, i finished it yesterday, but i'm not sure how to delete threads
     
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