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Is Left Side of Gauss' Law equation not the total electric flux?

  1. Sep 17, 2011 #1
    1. The problem statement, all variables and given/known data

    The total electric flux from a cubical box 40.0 cm on a side is 4700 Nm^2/C. What charge is enclosed by the box?

    2. Relevant equations

    Gauss Law: surface integral of E-field-vector * dA-vector = Q_enclosed/epsilon naught

    3. The attempt at a solution

    The reason I am making this post is that I was under the impression that the left side of Gauss' Law is the total (or net) electric flux over the surface of the shape. Why am I even being given the sides of the box? 4700 Nm^2/C, being the total electric flux, is the left side of the equation in Gauss' Law!

    Why is my answer of [4700 * epsilon naught] incorrect?

  2. jcsd
  3. Sep 17, 2011 #2


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    That answer is right, but remember that ε0 is a number. You should be able to give your answer in Coulombs.

    Also, you are right in saying you don't need the size of the box.
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