Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Calculate the resistance at 18 Celsius

  1. Oct 25, 2005 #1
    cant do this question, well i cant figure out what im supposed to do, whether its a thermistor or not, i worked out the inductance, but im not sure what to do after that, heres the question

    Calculate the resistance at 18 celcius of a 5cm diameter close-wound, single layer coil of 1000 turns of copper wire of 0.1mm diameter.

    what would its approximate resistance be at a temperature of 100 celcius???

  2. jcsd
  3. Oct 25, 2005 #2


    User Avatar

    Staff: Mentor

    Doesn't sound like they want the inductance -- sounds like they are asking for the resistance of the coil at two different temperatures. You need the rho of copper, and it's tempco (temperature coefficient). The total resistance R = rho*L/A, where L = total length, and A = area (of the wire cross-section in your case).

    If you have a chem table book or EE reference book handy, you can find the info in there. Or easier is to just google the following:

    +copper +resistivity +temperature

    and the first hit you get will give you what you need:


    BTW, I'm kind of a newbie to the PF forums, so I just learned recently that questions like this are supposed to be posted in the HW forums. So now I try to check out the HW question forums to see if I can be of help.
  4. Oct 25, 2005 #3
    thanks thats very helpful, i jus joined the forums, that was my first post, so i havent a clue what is going on in here anyways, cheers
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook