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Homework Help: Line of infinite charge and a gaussian sphere

  1. Oct 8, 2004 #1
    Construct a spherical gaussian surface centered on an infinite line of charge. Calculate the flux through the sphere and thereby show that it satisfies gauss law.

    I know how i can do it for a cylinder, but a sphere?

    I know that the ends of the wire (one diameter) wil have zero flux at it's ends

    but wouldnt i have to integrate over a big hemispherical surface and then multiply by two but ..... wouldnt it be tedious?
  2. jcsd
  3. Oct 8, 2004 #2


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    Yes, but that's probably the reason they're asking you to do it. It shows the power of symmetry in applying Gauss' Law.
  4. Oct 8, 2004 #3


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    It's not hard. You know what E(r) is. Take a point at polar angle \theta and find E(r).n in terms of \theta. Integrate over the sphere.
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