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Are the electrons from the wire moving?

  1. Jun 16, 2007 #1
    are the electrons from the wire moving? Let's say we have coil and magnet and closed circular loop and we have induced current with moving the magnet among the coil. Are the electrons from the coil only moving or also the electrons in the wire are moving?
     
  2. jcsd
  3. Jun 16, 2007 #2

    Astronuc

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    Another such question?

    Current by definition implies a group 'moving' charges.

    But yes - the conduction electrons throughout the conduction (wire) loop are moving. However, certainly not all electrons move. Most are still bound to their atoms.
     
  4. Jun 16, 2007 #3
    what is the thing that makes moving them? They are not affected by the magnet at all.
     
  5. Jun 16, 2007 #4
    The electrons? But they are affected by the magnetic field, by the Lorentz Force.
     
  6. Jun 16, 2007 #5

    Doc Al

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    What happens is that the changing magnetic field induces an electric field, and it is this induced electric field that drives the current. This is new physics, summarized in Faraday's law and, of course, Maxwell's equations.
     
  7. Jun 16, 2007 #6
    Do u know what is electric field? Every electron and proton have its own electric field. So from the one side there is lack of electrons (+), and from the other excess of electrons (-). So when we summarize the protons electric field we have one big "positive" electric field, and when we summarize the fields of the electrons we have "negative" electric field. However, the electric field is the thing that makes the electrons attract with protons, and electrons repel with other electrons. So !?
     
  8. Jun 16, 2007 #7

    Doc Al

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    I don't really know what you are talking about. The electric field associated with charges (like the electron and proton) is called a Coulomb electric field. But the induced electric field created by a changing magnetic field is different as it is not associated with a charge--but the field is quite real, nonetheless.
     
  9. Jun 16, 2007 #8
    It is not associated with charges? Man look, when you are moving the magnet among the coil, you "force" the electrons to go from one to another side. So from the one side there is lack of electrons (+), and from the other excess of electrons (-). Think about it. So from the + side, there are more protons, so summarize their electric fields. From the - side, there are more electrons, so summarize their electric fields. There will be created 2 bigger electric fields (electric field from side +, and electric field from side -). Summarize the two bigger electric fields! You get one bigger electric field like on this picture.
     
  10. Jun 16, 2007 #9

    Doc Al

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    You asked a question and I answered it. If you don't like the answer, too bad!

    The changing magnetic field induces an electric field--an EMF in the coil, which acts like a battery, driving a current through the closed circuit. The way the electric field is "transmitted" throughout the circuit is via small surface charges that rapidly build up on the wire.

    I suspect you are not ready to understand this kind of explanation. You need to start at the beginning and build your understanding gradually.

    Pick up a textbook, for crying out loud. (All of these questions you ask don't seem to be helping you.) Poke around here: Electricity & Magnetism Concepts

    You really need to find an introductory textbook, study it, and do lots of problems. Then you'll begin to see how it all fits together.
     
  11. Jun 16, 2007 #10
    You don't give me your explanation. I am asking you how do the electric field affect the electrons from the wire when they are not in any "contact" with it?
     
  12. Jun 16, 2007 #11

    Danger

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    I have been so tempted for a long time to launch an 'Aviator Alert', but have held off because there's been no mention of cannon balls on strings. Can there possibly be two of them?
     
  13. Jun 16, 2007 #12
    scientist91 ---


    Just to help things out---how old are you, how many years of schooling, and what country are you from?

    it may just be a language difference--thanks
     
  14. Jun 16, 2007 #13

    Astronuc

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    But electrons do interact with electric and magnetic fields, which permeate space.

    As DocAl indicated, one really needs to pick a text book on Electricity & Magnetism - or browse the Hyperphysics site as he suggested.

    The moving the magnet among the coil, induces a time varying magnetic field, which induces electrons to flow. Charge neutrality is maintained in the wire, and there is no local accumulation of electrons.

    Water flowing in pipe does not accumulate in a denser volume while being pushed or pumped. Think of the electrons like an incompressible fluid.

    Pushing on one electron (in a conductor) will affect the next electron (by virtue of their electric fields) and so on and so on, so they all flow together.
     
  15. Jun 16, 2007 #14

    ranger

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    Last edited: Jun 16, 2007
  16. Jun 16, 2007 #15
  17. Jun 16, 2007 #16

    Danger

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    Okay, now I'm just ashamed of myself. The language barrier doesn't really seem to be the problem, but I totally neglected to consider what age he/she might be. :redface:
    I used to assume that everyone was 10 years old, unless told otherwise, and responded accordingly. Somewhere along the line, I got jaded. Thanks for putting me back on track, Rewebster. :smile:
     
  18. Jun 16, 2007 #17
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