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Question about speed of an electric current

  1. Nov 24, 2014 #1

    Supposed I had 2 identical copper wires, I'll call them A and B.

    I insulate wire A with whatever the standard wire insulation is, and leave wire B alone (uninsulated).

    I'll now send an identical signal (same voltage and power) through each wire. Will the current be identical at the end of each wire? Will it be weaker or slower?

  2. jcsd
  3. Nov 24, 2014 #2


    Staff: Mentor

    That depends on the medium that the wire is in. If the medium is non conductive then it will be the same. But if the medium is conductive then the uninsulated wire will have less current.
  4. Nov 24, 2014 #3


    User Avatar
    Gold Member

    The situation you pose has nothing to do with the speed of the current, only with the amount, so your subject line is misleading.

    If you are interested in current "speed" then Google "electron drift velocity". You might be surprised.
  5. Nov 24, 2014 #4
    As you talk about "signal", do you have in mind a high frequency regime, with wave packets propagating along the line?
    In this case I think that the impedance of the line may depend on the medium. Probably that the losses too will depend on the medium.
    So both speed and damping of the signal may be different.
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