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Homework Help: How do I draw the diagram of the mirror charge

  1. Jul 15, 2011 #1
    1. The problem statement, all variables and given/known data

    Two point charges +q and -q are placed respectively in positions (-a, 0, +a) and (-a, 0, -a) of a cartesian reference frame, with a being positive and known. The half space of positive x is fully occupied by a conductor. What are the positions and values of the mirror charges in this specific case?

    The mirror charge for +q is: -q at (a, 0, +a)
    The mirror charge for -q is: +q at (a, 0, -a)

    how do I do this considering that 'the half-space of positive x is fully occupied by a conductor'

    3. The attempt at a solution

    drawing a line at y=0, z=0 on the x-axis but only for positive x
    but this is wrong
  2. jcsd
  3. Jul 15, 2011 #2


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    Staff: Mentor

    What geometrical object describes the interface between the filled half-space and the unfilled half space?
  4. Jul 15, 2011 #3
    all i could picture was this semi-infinite block filling the positive x space. but since you said the word 'interface' does it mean i can just sort of not see it as a block, and just see it as an infinite plane on the y-z plane? so i sketch the y-z plane?
  5. Jul 15, 2011 #4


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    Staff Emeritus
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    Everything is at y = 0, so I suggest you draw/sketch the zx-plane .
  6. Jul 15, 2011 #5
    "The half space of positive x is fully occupied by a conductor"
    i cant understand this line?
    which space?
  7. Jul 15, 2011 #6


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    Staff: Mentor

    You can sketch the yz plane and indicate that to the +x side is conductor, and to the -x side is empty space. If you want to get fancy, you can indicate a portion of the conductor region as a 'cutaway' section, implying that it extends indefinitely. Something like this:


    Attached Files:

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