Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: In what direction does the sphere move between two positive charges

  1. Sep 25, 2010 #1
    1. The problem statement, all variables and given/known data


    2. Relevant equations

    3. The attempt at a solution

    I understand that in question 25, the conductor becomes polarized and its negative charges will be more attracted toward the bigger 5uC charge, but what's the reasoning for question 26? I don't get why the answer isn't C. Don't dieletrics kill the electric field?
  2. jcsd
  3. Sep 25, 2010 #2
    The dielectric can be polarized. So you can also have surface charges, but instead of them being free, they are now bound. Then you will get a surface charge density much like the conductor but much smaller in magnitude.

    EDIT: Very similar to a balloon that you statically charge then hold it near a wall. The wall is a dielectric and will be attracted to the charged balloon.
    Last edited: Sep 25, 2010
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook