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Lenz's Law problem

  1. Jun 3, 2004 #1
    Hi, I'm just doing my A-level physics revision and there's something I'm a bit unsure about. Lenz's law states that an induced EMF will always act to appose the change that is causing the EMF in the first place. However, if we take the example of a magnet falling through a coil that is part of a circuit which has a gap in it, then an EMF is still said to be produced but there is no current. The magent in this case falls to ground with unchanged acceleration g. Surely though, if Lenz's law holds true and it is the EMF that opposes changes, then the magnet's acceleration downwards would be decreased just as it would if the circuit was complete.

    Any ideas would be of great help, thanks

  2. jcsd
  3. Jun 3, 2004 #2


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    Science Advisor

    That's a mis-statement of Lenz's law. The induced current will appear in such a direction that it opposes the change that produced it.
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