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Electron drift speed, Current, and Electric field in hollow wire?

  1. Feb 28, 2012 #1
    1. The problem statement, all variables and given/known data

    A hollow copper wire with an inner diameter of 1.4 mm and an outer diameter of 2.6 mm carries a current of 2.50 amps. Copper has an electron density of 8.5x1028 m-3 and a conductivity of 6.0x107 (ohm m)-1.
    a. What is the electron drift speed in the wire?
    b. What is the current density in the wire?
    c. What is the electric field in the wire?

    2. Relevant equations

    a) I=neeVdA

    3. The attempt at a solution
    I believe I have the correct answers but was just curious if someone could double check me!
    Thank you!

    Attached Files:

    Last edited: Feb 28, 2012
  2. jcsd
  3. Mar 12, 2012 #2
    Bra, your algebra is wrong. When you find the area, do it for each section separably and subtract them from each other you will see your error. X^2-Y^2 does not equal (X-Y)^2
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