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Homework Help: E-Field of non-conducting plane

  1. Apr 27, 2005 #1
    Three very large sheets are separated by equal distances of 20.0 cm (Fig. 22-42). The first and third sheets are very thin and nonconducting and have surface charge densities of +6.50 µC/m2 and -6.50 µC/m2, respectively. The middle sheet is conducting but has no net charge.

    http://img.photobucket.com/albums/v225/Fanman22/22-42alt.gif [Broken]

    What is the electric field between the left and middle sheets?
    What is the electric field between the middle and right sheets?

    Since it says the sheets are very large, and there is only a 0.2m separation between the surfaces, it seems logical that the E-field can be considered as calculating the field at a point close to the surface with the following equation:

    E = charge density / (2*epsilon) = 6.5e-6/(2*(8.85e-12)) = 3.67e5 N/C

    But apparently that is wrong even though I am reading it straight from my text!?!? :yuck:
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Apr 28, 2005 #2


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    Perhaps you are not including all the charge that produces an electric field in that region. Think about the field for one plane of charge; then think about the field from multiple planes of charge.
    Last edited by a moderator: May 2, 2017
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