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Zero point in the electric field

  1. Feb 7, 2013 #1
    1. The problem statement, all variables and given/known data

    Find positions on the x axis for the charges Q1 = -1 C and Q2 = +3 C so that the electric field is zero at x = 0.

    2. Relevant equations

    where E=kq/r^2

    3. The attempt at a solution
    I put q1 and q2 1 meter apart and then found where a third charge would go so the third charge would have a force of zero. My answer for the question is q2 at x=-2.366 and q1 at x=-1.366. Is this right?
  2. jcsd
  3. Feb 7, 2013 #2


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    Staff Emeritus
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    Yes, that is one possible answer. (There are an infinite number of sets of possible answers.)

    The important thing is the ratio of the two x coordinates.
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