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Homework Help: Resistance and resistivity

  1. May 9, 2006 #1
    A resistor is to have a constant resistance of 30(ohm), independent of temperature. For this, an aluminium resistor with resistance R1 at 0(celcius) is used in series with a carbon resistor with resistance R2 at 0(celcius). Evaluate R1 and R2, given that [tex]\alpha 1[/tex] is 3.9 x 10^-3 for aluminium and [tex]\alpha 2[/tex] is -0.5 x 10^-3 for carbon.

    Can anyone give me some clues to solve this question? Thanks in advance.
  2. jcsd
  3. May 9, 2006 #2


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    Homework Helper

    Start with the definition of alpha.
  4. May 9, 2006 #3


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    Resistances in series ...
    there's a way to represent these with a single equivalent resistance ...
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