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Homework Help: Conductivity homework problem help

  1. Nov 7, 2009 #1
    1. The problem statement, all variables and given/known data
    At what temperature does a carbon resistor have a resistance of 995 ohms, if it has a resistance of 1000 ohms at 20 degrees? What is its conductivity at the new temperature?

    2. Relevant equations

    3. The attempt at a solution
    I don't even know where to start.
  2. jcsd
  3. Nov 7, 2009 #2
    Re: Conductivity..

    Do you have any equations that relate the change of some property (e.g. resistivity) of a conductor with temperature changes?
  4. Nov 7, 2009 #3
    Re: Conductivity..

    Well, the situation isn't ideal. We recently got a new teacher, after our old teacher canceled 2 weeks of classes. Now we are trying to catch up so we have an assignment on material we haven't covered. I also have no textbook for the class. I did google searches but could only find R= conductivity*L/A but I don't have length or area.
  5. Nov 7, 2009 #4
    Re: Conductivity..

    Check out this link then:


    Then think about the connections between resistance, resistivity, and conductivity.

    I don't understand why there is no text for the course. Is this a college-level course? There are many older editions of quality texts that you can get dirt cheap through Amazon.com, for example.

    Also, the equation you quoted in your previous post should have "conductivity" replaced with "resistivity", according to one of my texts.
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