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Homework Help: Electric Field hard question

  1. Sep 15, 2008 #1
    Electric Field hard question :(

    1. The problem statement, all variables and given/known data

    What is the electric field between two parralel plats, each of area 1 m^2 which are separated by a distance of 0.01 m, if each plate is charged equally but oppositely with a charge of magnitude 8.84 x 10^-8 C?

    2. Relevant equations
    E= kQ/ d^2

    3. The attempt at a solution
    i tried to find the electric field at each plat using E= kQ/ d^2. Because it says in the question 'find the electric field between the two parralel plates, does this mean the midpoint?
    i dont really get what to do with the area either?
    Any Help would be greatly appreciated
    THANKYOU :^)
  2. jcsd
  3. Sep 15, 2008 #2
    Re: Electric Field hard question :(

    The electric field between two parallel plates, when their separation is much smaller than their size, is uniform (as long as you stay away from the edges)
    and has a magnitude equal to the charge density divided by the permissivity of the medium.

    The area is given to you so that you calculate the charge surface density. I think you can find plenty of information on this topic in any good electrostatics textbook.
  4. Sep 15, 2008 #3


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    Homework Helper

    Re: Electric Field hard question :(

    Make use of Gauss law and symmetry here.
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