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Homework Help: Electric Potentials

  1. Feb 24, 2005 #1
    A hollow cylindrical shell of length L and radius R has charge Q uniformly distributed along its length. What is the electric potential at the center of the cylinder?

    I use eta = Q/A = Q/2piRL

    dq = (eta)*dA = Q/(2piRL)*2piRdL

    dV = 1 / 4 pi epsilon 0 * dq/r where r = sqrt(L^2+R^2)

    V = Q/(4*pi*epsilon_0)*int(dL/(sqrt(L^2+R^2)))

    This seems to be incorrect can someone tell me where I have gone wrong?

    Thanks in advance.
  2. jcsd
  3. Feb 24, 2005 #2
    You are missing an H = height of the cylinder in the denominator of the equation.

    Also limits of the integral (-h/2 -> h/2) if your referance point is the middle of the cylinder.
    Last edited: Feb 24, 2005
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