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

Help me understand Electro-induction

  1. Nov 8, 2012 #1
    Imagine you have a cylindrical dielectric charged with 100KV on one end and -100KV on the other end.

    Now take an uncharged metal ball and bring it close to the positive end of the dielectric.

    From what I understand, the metal ball will be induced into having a charge that will come close to -100KV, depending on how close it comes to the dielectric, via Electrostatic Induction.

    When this is done, is there any transfer of energy? Does the dielectric change in any way? If so, in what way?
    I can't find any equations that characterized the change in charged matter, or the change in uncharged matter..
  2. jcsd
  3. Nov 8, 2012 #2


    User Avatar
    2017 Award

    Staff: Mentor

    Charge is not induction. The metal ball will not get a net charge (unless it has contact to something else) - it will have some charge separation, with less electrons close to the -100kV-point and more electrons far away.

    Why do you use a cylindrical dielectric? Two charged objects (conductivity does not matter) would do the same.

    Some energy of the electrostatic field is used to separate the charges.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook