1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Potential of two parallel infinite wires

  1. Feb 13, 2014 #1
    1. The problem statement, all variables and given/known data
    Two parallel infinite wires lay parallel to the z-axis in the xz-plane. One located at x=d has charge distribution λ and one located at x=-d has charge distribution -λ.

    2. Relevant equations

    a) Find the potential V(x,y,z) using the origin as a reference
    b)Show that the equipotential surfaces are circular cylinders parallel to, but not coaxial with, the wires. For a given V_0 determine the corresponding axis and radius of the cylinder.

    3. The attempt at a solution

    I believe we can approach this problem with gaussian surfaces, but i am confused on how to exactly use the fact that the origin is a reference. Also the fact that its in cartesian is messing with my ability to do the problem, there is so much cylindrical symmetry...
  2. jcsd
  3. Feb 13, 2014 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    Normally you'd do this problem for one wire, with the wire along the x axis or similar.

    This gives you an equation for the electric field about that axis.
    What happens to that equation if the wire is not on the axis?

    Hint: if a simple parabola were centered on the y axis it would have equation ##y=x^2##, if it were now centered on the line x=d, it would have equation ##y=(x-d)^2##.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted