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Homework Help: Nichrome Resistor and Copper wire

  1. Mar 4, 2009 #1
    1. The problem statement, all variables and given/known data
    A 10 ohms Nichrome resistor is wired into an electronic circuit using copper leads (wires) of diameter 0.6 mm with a total length of 50 cm. The additional resistance is due to the copper leads is 0.03 ohms.

    What change in temperature would produce a change in resistance of the Nichrome-wire equal to the resistance of the copper leads?

    2. Relevant equations

    RCu = 0.03[1 + aCu(tC – 20)]= change in Rw = 10aw(tC – 20); solve for tC
    aCu at 20 degree C= 3.9 x 10^-3
    aw at 20 degree C = 4.3 x 10^-3

    3. The attempt at a solution

    0.03[1 + aCu(tC – 20)] = 10aw(tC – 20)
    I solved for tc and got 30.6 C but it is not the right answer so please help.
  2. jcsd
  3. Mar 5, 2009 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    Welcome to PF :smile:

    30.6 C does not solve the last equation you wrote. There must have been some algebra error made after that.

    You are on the right track, try again. You can check your answer by substituting it into your equation,
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