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Help with fundamentals for understanding voltage, current, anode

  1. Nov 3, 2014 #1

    I have never been good at understanding how electricity works, I would appreciate very much if someone could help me get a good picture on my questions, maybe with some visual/easy/logical examples/thoughts?

    Electrons have a charge, in a metal they are free to move around, a charge in motion constitutes an electric current. So for so good I would say, but here is where it all becomes fuzzy.

    In an example that I connect a battery to a copper wire:
    Next thing that I would guess would happen is that the electrons would move from the negative pole of the battery to the positive pole.

    1) The battery is a chemical solution that draws out electrons, and with time this degrades (resistance of the battery increases) and the voltage of the battery gets lower?
    2) Is the current I measure from the electrons of the battery or from the copper wire?
    3) So a bunch of electrons arriving to the positive pole at the battery, what happens next? Do they continue through the battery and end up att the negative pole again?

    4) The measuring of the current can be calculated through some equations, I read somehwere that the electron couples with the elctrode, something like that. But what happens when the electron hits the electrode?

    What caused me to ask these questions is because I am reading about electron multiplier tubes, so questions regarding that:

    5) When an electron strikes the dynode it collides with other electrons and some are ejected along with it, would the dynode not get depleted of electrons after a couple of uses?
    6) What is the "information" the anode recieves, is it the motion of the electrons in the tube, or the collision of the electrons with the anode?
    7) What happens when the electrons strikes the anode, they should be removed somehow, otherwise they would build up a space charge and no electrons would eventually accelerate towards the anode.

    Thank you very much for your time
    I would greatly appreciate answers
    Kind regards
  2. jcsd
  3. Nov 3, 2014 #2


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    Gold Member

    Two points to keep in mind before you ask all those questions:

    Rotating a magnetic field around a wire induces a current.....like a generator for example.

    Pushing a current through a wire induces a rotating magnetic field.....like a motor for example.
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