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

Free Charges in a Dielectric Sphere

  1. Aug 20, 2011 #1
    Why is it that a dielectric sphere containing free charges, uniformly distributed throughout, has a net electric field? If the sphere is electrically neutral, then all the charges should cancel out, and since the free charges are uniformly distributed, I don't understand why there should be an electric field inside the sphere.
    Thanks
     
  2. jcsd
  3. Aug 20, 2011 #2
    What do you mean? If you say it contains free charges, I think it means that extra charges are added to the sphere because charges of electrons and nuclei are not "free", unless it is in metal. Perhaps I've misunderstood.
     
  4. Aug 20, 2011 #3
    Sorry about the lack of clarity in my question! It was a reflection of the lack of clarity in my mind.
    I think I understand the situation now. The sphere starts off as being electrically neutral, then the free charges are added to the sphere, producing an electric field inside it and outside it.
    Am I right in saying that free charges are always added to the dielectric, and the bound charges are always already in the dielectric?
    Thanks!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook