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Homework Help: How does change in current induce electromotive force

  1. Jul 20, 2009 #1
    Reviewing the definition of inductance, I found the following definition from Wikipedia:
    Can someone explain to me how change in current will induce an electromotive force (one that will oppose the present current)? And what is meant by a magnetic field is inductive?


    Last edited: Jul 20, 2009
  2. jcsd
  3. Jul 20, 2009 #2
    Re: Inductance

    Are you familiar with Lenz's Law? A current in a circuit will produce a magnetic field, so when current is changed, magnetic field is changed, and a changing magnetic field will induce an EMF that opposes the change. If I'm not mistaken, this is what people refer to as "back-EMF" in circuits.
  4. Jul 20, 2009 #3
    Re: Inductance

    Is there a picture or video I can see of this, so I can see the direction of the EMF in relation to the magnetic field?
  5. Jul 20, 2009 #4


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    Science Advisor

    Re: Inductance

    See the right-hand grip rule which relates current direction through a conductor to magnetic field orientation. Induced EMF will be in opposition to the current flow.
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