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Gauss's Law

  1. Oct 3, 2013 #1
    Hey everyone,
    I was wondering if someone could explain Gauss's law. For whatever reason, I just cannot grasp this idea (might be my teacher). I understand that the electric field through a surface can be represented as [itex]\oint \vec{E} d\vec{A}[/itex] but every problem that we do ends up resulting in it equaling [itex]E\oint dA[/itex] and finally EA. I really don't even understand this equation, how to use it, how to apply it, etc. If anyone could clear this up that'd be great.

  2. jcsd
  3. Oct 4, 2013 #2
    guass law: the total flux through a surface is (1/[itex]\epsilon[/itex]) times the total charge enclosed within it .. we take integral of E.ds to arrive to a equation ie [itex]\phi[/itex] = q/[itex]\epsilon[/itex] .
    while integrating consider a point charge and make a guassian surface of a sphere, and you will find that kq/r2*4∏r2. now this 4∏r2 gets cancelled with your k and r2... hence we take integral of that to arrive at equation.
  4. Oct 4, 2013 #3

    Claude Bile

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    The integral form of Gauss's Law is used to work out the charge enclosed by a surface by integrating the electric flux over that surface.

    The reason E can frequently be taken outside the integral is that Gauss's Law is independent of the chosen surface. So it makes sense to choose a surface with nice symmetry that makes the integral as simple as possible.

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