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Homework Help: Three concentric conductors, one grounded (Potential)

  1. Sep 28, 2011 #1
    1. The problem statement, all variables and given/known data

    See figure attached.

    2. Relevant equations

    3. The attempt at a solution

    See figure attached.

    I'm confused how they deduced that V1-V2 is going to be the integral of the electric field from a to b.

    How do they choose the path from a to b?

    How can they say that the electric field integrated over this path is going to be V1-V2?

    I express the same confusion over the 2nd integral, why is V2 equal to the electric field integrated from c to d?

    Attached Files:

  2. jcsd
  3. Sep 29, 2011 #2


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    Science Advisor
    Gold Member

    The path doesn't matter. Since this is an electro-static problem, the E field is a conservative field, meaning that integrals are path independent. You can find a proof of this in most elementary E&M texts. The voltage between two points is the path integral of E between those two points, that is how it is defined.
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