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Homework Help: Lamp and tugsten

  1. Jan 14, 2007 #1
    1. The problem statement, all variables and given/known data

    [tex]p_t=p_{20}(1+\alpha (t-20))[/tex]

    I have a circuit with a 3,5 V lamp that has a tungsten filament. I can provide to the circuit a variable voltage. How would I find the melting temperature of tungsten?

    I know p_20 and alpha and the voltage I provide. And I have an device to measure current too.

    Could I just increase voltage until the lamp turns off (which means the tungsten filament melted), measure the current and by means of Ohm's Law I could find the resistance. And then with the initial formula, I could find the temperature to which corresponds this resistance.

    Am i right? Sorry my poor English.
    Last edited by a moderator: Jan 14, 2007
  2. jcsd
  3. Jan 14, 2007 #2
    knock, knock...

    Sorry to reply to my own thread, but I have some urgence to solve this, please, please...
  4. Jan 14, 2007 #3


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    Gold Member

    If you're expecting to have homework problems solved for you within 2 hours, then you're probably at the wrong place.

    What happens if you follow up on your original reasoning? Also how are your terms defined?
  5. Jan 14, 2007 #4
    You are totally right. I am sorry...
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