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Homework Help: Charge enclosed in uniform electric field

  1. Jan 18, 2009 #1
    1b]1. The problem statement, all variables and given/known data

    A cube oriented so that its corner lies on the origin and it extends positive 1m in the x, y, and z direction. An electric field of 3.00 i + 2.5 j passes through this space. What is the charge enclosed by the cube?

    3. The attempt at a solution

    Gauss' law is
    integr(E . dA) = Q/epsilon

    since the surface is of a cube, you can add the dot product of E and dA for every face except for the one lying in the x-y plane because there is no 'k' component of the E field.
    The dot products of the faces cancel out though
    So the the total charge enclosed is 0
    is that right?
  2. jcsd
  3. Jan 18, 2009 #2


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    Homework Helper

    If the electric field is uniform across the space the cube is in, then you are right that there is no charge inside, because for there to be a charge inside there would have to be a net non-zero flux through all of the faces of the cube.
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