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: Charges near a conducting plane

  1. Jan 13, 2015 #1
    1. The problem statement, all variables and given/known data
    Locate two charges q each and two charges –q each on the corners of a square, with like charges diagonally opposite on another. Show that there are two equipotential surfaces that are planes. In this way obtain, and sketch qualitatively, the field of a single point charge located symmetrically in the inside corner formed by being a metal sheet through a right angle. Which configurations of conducting planes and point charges can be solved this way and which can’t? How about a point charge located on the bisector of a 120° dihedral angle between two conducting planes?

    2. Relevant equations

    3. The attempt at a solution

    I understand this is an extension of the method of image charges and I think that only conducting planes at 90° to each other can be solved in this way. For the 120° case, the image charges lie on the plane of the two conducting planes and there is no good way to introduce another image charge so that the potential at the planes is constant. Is this correct?
  2. jcsd
  3. Jan 13, 2015 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    That looks right to me.
    No, I believe there are other angles. Which ones won't have the problem you mentioned in respect of 120 degrees?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted