1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: 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



    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!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook