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Homework Help: Potential of a Charged Cylinder

  1. Nov 5, 2007 #1
    1. The problem statement, all variables and given/known data

    A hollow cylinder of radius r and height h has a total charge q uniformly distributed over its surface. The axis of the cylinder coincides with the z axis, and the cylinder is centered at the origin, as shown in the figure.

    21165_a.jpg

    What is the potential V0 in the limit as h goes to zero?

    Express your answer in terms of q, r, and ε0.

    2. Relevant equations

    http://photo.ringo.com/240/240690564O546905961.jpg [Broken]

    3. The attempt at a solution

    with h=0, the values under the root would be 1 (1+0), and the other values in the parenthesis would be zero, so we would have ln(1) which is 0, and then 0 multiplied times the rest would also be 0, but this is incorrect.

    Thanks in advance for the help!
     

    Attached Files:

    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Nov 5, 2007 #2

    Chi Meson

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    Where is Vo to be measured? On the surface I assume? And as h goes to zero, this becomes simply a circular charge distribution, doesn't it?
     
  4. Nov 5, 2007 #3
    to perform that limit use l'hospitals rule from calculus. and like the previous states you need a reference point to calculate potential is it in the center or is it along the z axis
     
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