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Understanding induced emfs

  1. Feb 11, 2012 #1
    So if a circuit goes once around an extremely long solenoid whose changing current causes an induced emf of 360 V (in the circuit) at a particular time, does that mean that regardless of the shape of the circuit, the induced emf will be 1 V per degree? If the circuit has only one resistor whose beginning and end make a 1 degree angle with the center of the solenoid, does that mean that the potential difference across that resistor is 359 V at that moment in time?
  2. jcsd
  3. Feb 12, 2012 #2


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    That's right, provided the circuit path is close to the solenoid relative to its length.

    [edit]... another qualifier, the resistance needs to be high enough so that the induced current is insignificant. There's a self inductance effect in the circuit, and for that calculation, shape DOES matter.
    Last edited: Feb 12, 2012
  4. Feb 12, 2012 #3
    Oh ya! I didn't think about self-inductance; I think that's the next thing I learn about. Thank you.

    This should be taught better in 1st year physics courses.
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