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Changing electric flux caused by a resistor

  1. Feb 11, 2012 #1
    I'm learning the basics about electromagnetism, including that a changing electric flux through an open surface causes a magnetic field. Obviously a capacitor causes this, but doesn't a resistor like a light bulb (whose resistance varies with temperature and therefore time) also cause this?
  2. jcsd
  3. Feb 11, 2012 #2
    Yes. Part of the magnetic field around the resistor comes from the current that flows through it. Another part comes from the time-changing electric field that spans it. You would model this as a capacitor in parallel with the resistor.
  4. Feb 11, 2012 #3
    That makes sense. Thanks. I assume that the resistance of ALL resistors increases with increasing temperature. Is there a crude, classical physics model to understand why this is so?
  5. Feb 11, 2012 #4
    I'm going to take a stab at answering my own question from post 3. I think that as the temperature goes up, the average distance an electron in a resistor travels before changing direction decreases because the atoms in the resistor are jiggling faster. Is that right?
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