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Electrostatic force between point charge and dielectric ball.

  1. Oct 5, 2011 #1
    At a certain distance from a point charge q there is small, dielectric
    ball. How would change the value of electrostatic force
    acting on the ball, if the value of a point charge would be doubled?
    According to F=k[(q1*q1)/r^2] there would be no force on the dielectric ball, because his resultant charge is 0. Is it so? Please hint.
     
  2. jcsd
  3. Oct 5, 2011 #2

    Matterwave

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    Are you sure that the dielectric ball won't be polarized in the presence of the charge?
     
  4. Oct 5, 2011 #3
    Truth. So the force would double, wouldn't it?
     
  5. Oct 5, 2011 #4

    Matterwave

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    I would think that doubling the charge would proportionately increase the polarization of the sphere. I would suspect, based off intuition, that the force would more than double.

    A full treatment of the problem should be that you find the E fields outside and inside the dielectric ball, and then use stress tensor to get F=TdA. What level of E&M are you in?
     
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