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Homework Help: Temperature coefficient of resistance problem

  1. Jun 19, 2011 #1
    1. The problem statement, all variables and given/known data

    For the resistance versus temperature graph below, find (a) the resistance at T = 20°C and (b) the temperature coefficient of resistance alpha .


    I don't know if the graph is showing up or not, it isn't for me... so here's the link.

    3. The attempt at a solution

    I believe that this is the formula i am supposed to use, but i feel like i dont have enough numbers or data to plug in. R(T) = R(To) ( 1 + alpha (T-To) )
    Last edited: Jun 20, 2011
  2. jcsd
  3. Jun 20, 2011 #2


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    Homework Helper

    You can use the formula
    α = (R2 - R1)/(R1t2 - R2t1)
    From the graph, you can see that at 20 degree C R1 = 5.1 ohm and at 30 degree C R2 = 5.2 ohm. find α.
    Interpolate the graph towards the axis. You can find R(0). Then use the formula which you have mentioned to find R(20)
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