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Homework Help: Potential of two infinite lines of charge

  1. Feb 28, 2008 #1
    This is the question I have: consider the system formed by two infinitely long line charges located in the xy plane running parallel to the x axis at y = + and - a and carrying uniform charge densities + and - lambda respectively. Find the elctrical potential at all points in space using the origin as your referenc point.

    Because the lines of charge do not run along the x axis, I assume that I'm going to have to use curly r in my answer (ie. r minus r prime). So, assuming I use the equation that involves the integral of lambda over curly r, integrated over r prime, how do I rewrite curly r so that I can integrate properly?

    Or am I going about this all wrong?

    Any advice would be appreciated.

    W. =)
  2. jcsd
  3. Feb 28, 2008 #2


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    Use Gauss's law to get the E field of a single line charge.
    Then, just add the E's from each line charge.
  4. Feb 28, 2008 #3
    I'm looking for potential, not the electric field.

    Also, because the lines of charge run parallel to the x axis, not along it, then r doesn't originate at the x axis, so I'll need to figure out how to compensate for that (which is what I'm having difficulty with).
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