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What comes first in a closec circuit eletron movement or the electic feild.

  1. Aug 18, 2011 #1

    I'm trying to get an image of a reasonably detailed model of electric current of standard close circuit with an electrochemical battery into in my head, well to an A level standard, I’m a fairly visual learner so image descriptions help :)
    I’m also very new to physics, I’ll try and describe this the best I can, but sorry if it’s confused.
    From my reading of the physicsclassroom.com and internet,

    I’ve read the electric field is generated by the PE difference across the two terminals and it is this which causes the movement of electrons around the circuit, but I’ve also read that it’s the electron movement that generates the field.

    But what comes first? When the wire is connect to battery does the field appear and force (just as two like charges repel) the delocalized electrons to move with the field? From high to low PE.

    I think my understand might be wrong as this seems a bit like the chicken and the egg to me, the field moves the electrons, the electrons create the field, which comes first?

    1) Where is this field coming from, and at what point in time upon making the connection does it appear.
    2) How does the field know to surround the wire if it’s not directly related physical metal
    3) Is the field around the wire or inside the wire.
    4) How does it relate to the magnetic field that surrounds the wire, or is this a separate phenomenon? (the books make it sound like separate thing) Is it truly the field that moves the electrons?
  2. jcsd
  3. Aug 18, 2011 #2
    How about lets start with a capacitor. 2 metal plates one with +Q charge and the other with -Q charge . So there is an E field going from + to - . And there is a voltage V=Ed
    d is the spacing between the plates. Now when i connect these 2 plates with a wire the E field will push the free electrons in the wire to the other side until the voltage is 0. There has to be an E field to push the electrons. E fields are created from free charge.
    When i connect a wire to a battery the E field starts to push the electrons, and when one electron starts to move its own E field inside the wire will push the next electron in front of it and this will be a chain reaction and almost be instantaneous. And when a currents starts to flow in the wire it will create a magnetic field. B fields are created by currents or changing E fields.
  4. Aug 19, 2011 #3
    That does help thank you, I didn't know the Electrons created their own feilds. Given me something to think about and research :)

    Thanks again,
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