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Homework Help: Resistance is known. Length of wire?

  1. Sep 30, 2009 #1
    1. A 10 AWG Solid Copper wire has a resistance of 2 ohms. The wire length is?

    2.Resistance = Resistivity x (Length/(V/L)) = Resistivity x (L^2/V).

    3. 60.8 feet 60.8 m 6.1 m 200 inches are my possible answers

    No matter what math I do. . .I can not reach any of the possible multiple choice answers. So my formula or math is wrong somewhere. Can someone please help me.
  2. jcsd
  3. Oct 1, 2009 #2


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    The formula is correct. How did you calculate V?
  4. Oct 1, 2009 #3
    The formula I used is: R = p X l / a

    R = resistance of conductor, in ohms
    p = resistivity of conducting material
    l = length of conductor, in feet
    a = area of conductor, in circular mils

    Turns out the formula is correct. The professor listed the wrong possibilities for l. I just received the email from her confirming the error. Turns out that l = 608 meters. Thank you very much for your help.
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