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Homework Help: Electron drift speed

  1. Feb 7, 2005 #1
    The electron drift speed in a gold wire is 3.0 * 10^-4.

    1. What is the current density in the wire?

    2. What is the current if the wire diameter is 0.50 mm?

    J = I / A
    and I = nqva

    What is the answer?
  2. jcsd
  3. Feb 8, 2005 #2


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    Homework Helper

    You get from your formulas that the current density is J = nqv.
    You should know the meaning of the letters.
    n is the number of free carriers in unit volume. q is the charge of the free carriers and v is their drift speed.
    Is anything you do not know from these?

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