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Electric Field due to a charged conducting sheet

  1. Feb 22, 2013 #1
    1. The problem statement, all variables and given/known data

    A conducting sheet 10m x 10m x 1mm carries a charge of 1 mC. What is the electric field magnitude in kV m-1 just above the centre of the sheet?


    2. Relevant equations

    ρ=Q/Volume

    E=ρ/2ε0

    3. The attempt at a solution

    I have arrived at an answer by the following:

    ρ = 1x10-3C / 10m x 10m x 1mm = 0.01C/m3

    E = 0.01 / 2 x 8.85x10-12 = 565MV/m

    However, the answer is given as 565kV/m, which I can only arrive at if I use 8.85x10-9 as the free space permittivity. Where have I gone wrong?


    Many thanks.
     
    Last edited: Feb 22, 2013
  2. jcsd
  3. Feb 22, 2013 #2

    Doc Al

    User Avatar

    Staff: Mentor

    The density you need is the surface charge density, Q/Area (which is usually represented by σ). (Not the volume charge density ρ.)
     
  4. Feb 22, 2013 #3
    Ah. Whoops. Thank you very much!
     
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