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Homework Help: Gauss' Law and a uniform surface charge

  1. Sep 14, 2006 #1
    Use Gauss' Law to find the field inside and outside a long hollow cylindrical tube which carries a uniform surface charge sigma.

    It has been a few months since i did this so i may be a bit rusty

    As i can recall if there is a point inside a holow cylindrical tube there is no enclosed charge, hence the electric field is zero inside the tube for all points inside

    for the outside
    For a radial ditance of r from the tube of length L
    [tex] \vec{E} d(2 \pi \vec{r} L) = \frac{\sigma L}{\epsilon_{0}} [/tex]

    hence [tex] \vec{E} = \frac{\sigma}{2 \pi r \epsilon_{0}} \hat{r} [/tex]

    is this fine??

    thank you in advance for the help!!
  2. jcsd
  3. Sep 16, 2006 #2
    You got the right results.
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