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Homework Help: Net Electric Potential

  1. Oct 19, 2004 #1
    Need a little help with a homework problem, I don't seem to understand the theory behind this.

    Figure 25-23 shows four pairs of charged particles. Let V = 0 at infinity.

    http://www.webassign.net/hrw/25_23.gif
    Figure 25-23.

    (a) For which pairs is there another point of zero net electric potential on the axis M between the particles?
    ChkBox 4
    ChkBox 2
    ChkBox none
    ChkBox 1
    ChkBox 3

    (b) For which pairs is there another point of zero net electric potential on the axis M to their right?
    ChkBox 2
    ChkBox 1
    ChkBox 4
    ChkBox none
    ChkBox 3

    If you can just give me some hints on where to start or what to look for, would appreiciate it.

    Thanks for your time,
    RishiD
     
  2. jcsd
  3. Oct 20, 2004 #2
    The electric potential is given by

    [tex] V = \frac{kQ}{r} [/tex]

    So, you need to add the potentials of both the charges in all the situations at the place where the potential is desired. ( put proper sign of the charge ).

    Without doing the calculations, you can see where the potential can come out be zero. ( if you take care of the negative and positive terms )


    spacetime
    www.geocities.com/physics_all/index.html
     
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