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Homework Help: Resistivity with temp

  1. Feb 14, 2005 #1
    :confused: oki, here's the deal, i have a 540W heating coil 110V nichrome wre 0.600mm in diameter. considering the variaion of resistivity with temperature, waht will the coil 4.2236 m actually deliver when it is heated to from 1200 C from 20 C. i have tried using R=R[o]*(1+alpha8(T-T[o]) and using alpha as .0004 and R as the ohms found from wattage and volts. where am i going wrong?
     
  2. jcsd
  3. Feb 14, 2005 #2

    Gokul43201

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    This question is very poorly worded. Would you please write it down EXACTLY as it appears in your homework ?

    If you're asking for the power delivered at 1200C, P = V^2/R(1200C) should give you the answer. You may also have to consider the change in resistance due to thermal expansion, though I think this may be small.
     
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