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Homework Help: Distribution of charge on two spheres

  1. Oct 4, 2015 #1
    1. The problem statement, all variables and given/known data


    2. Relevant equations

    3. The attempt at a solution

    I believe the entire charge Q has to be given to any of the sphere such that one charge is neutral ,while the other has charge Q . In this way there would be no electric force between the two spheres and only attractive force between them would be gravitational .

    Is my answer as well as my reasoning correct ?

    Many Thanks

    Attached Files:

  2. jcsd
  3. Oct 4, 2015 #2


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    Staff: Mentor

    You would still get an induced charge distribution on the uncharged sphere, which leads to a small attraction (but still much larger than the gravitational attraction for typical setups).

    The question is weird. It would be a nice question if it would ask for maximal repulsion.
  4. Oct 5, 2015 #3
    I think we have been given condition (d > > R) so that we could neglect the effect of induced charges . I am not entirely sure .

    Do you believe that there is a possibility that force of attraction could be greater if charges were distributed differently i.e by not giving complete charge to one of the spheres ?
    Last edited: Oct 5, 2015
  5. Oct 5, 2015 #4


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    I don't see how. You can cheat and add +2 Q on one sphere and -1 Q on the other (sum: Q), but I doubt that's the intended solution. It also would mean there is no well-defined maximum.
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