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Homework Help: Obtain the resistance of a ntc thermistor

  1. Nov 3, 2005 #1
    Please Help!!!!!

    HI.
    Im really struggling to work out how to obtain the resistance of a ntc thermistor from just having the temperature. Ive been given the characteristic temp. of 3900K, labelled B for some reason. the only equation i can find to use is R = A.e to the power of B/T. I think this is somwthing to do with the base of natural logarithms, but when i asked my lecturer, he said no knowledge of logs was needed.
    Please help!

    Thank you loads in advance..
     
  2. jcsd
  3. Nov 3, 2005 #2

    verty

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    Is there any more information?
     
  4. Nov 3, 2005 #3
    The question asks that if the ntc thermistor has a resistance of 47 ohms at 20 degrees celsius, and its characteristic temp is 3900K then what is its resistance at 100 degrees celsius?
    I cant even find a suitable equation which relates its resistance to its temperature.
     
  5. Nov 3, 2005 #4

    verty

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    I am going to guess here because I don't actually know. I'm guessing the resistance is 0 at the characteristic temperature. Perhaps you know about that. I will also assume a linear relationship. If it isn't linear, you need more information anyhow.

    Assuming this, it's a ratio. Actually, I'll let you work it out rather. Try with these assumptions.
     
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