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Electric field and electric charge inside the Earth?

  1. May 12, 2015 #1
    As we know, If you put charge on conductor then all the charge reside on the surface of the conductor and charge inside the conductor is zero and electric field is also zero.

    Earth is also a good conductor. So the charge resides on the earth surface?
    Is there no charge inside the earth?
    And Electric field is zero inside the earth?
  2. jcsd
  3. May 12, 2015 #2


    Staff: Mentor

    Close to zero maybe, but not exactly zero. Earth has a magnetic field that is generated by the circulation of charges deep inside the liquid molten core. The existance of that magnetic field tells us that the charges must be nonzero.

    Read about the geodynamo on wikipedia.
  4. May 12, 2015 #3
    So there is contradiction between metal conductor and earth conductor.
    Because it is zero in metal but not in earth but both are good conductor.

    And the property of the conductor says that charge always resides on the surface of the conductor but it is not happen in case of earth.
    Then how to understand this.
  5. May 12, 2015 #4


    Staff: Mentor

    It is not a contradiction. It is a question of complexity. A conducting metal sphere (including Earth) has zero internal fields. However the Earth has many internal materials, some conducting , some not. The materials move. Some have piezoelectric properties.

    The total internal charge of a local region inside the Earth is thus approximately zero but not exactly zero. You could also say that most .ocal regions are approximately conductors.

    Whenever you mix up idealized theoretical concepts with real life, you risk confusing yourself with apparent contradictions that are not real. Few things in real life are ideal or pure.
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