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Homework Help: EM induction

  1. Jul 8, 2008 #1
    1. The problem statement, all variables and given/known data

    The sketches below show a circular coil and a permanent magnet; the arrows indicate both the magnitude and the direction of the velocities of the magnet and coil. In which situations will the induced voltage (and hence the current) in the loop be zero? (Enter your answer in alphabetical order, without spaces or commas, e.g., AF.

    2. Relevant equations


    3. The attempt at a solution

    B - because the South pole is facing the loop and the direction out of N is going to loop around to S, and not have any effect on the loop.

    D - the N is going to again going to go to S and leaving the loop alone.

    I could be completely wrong on this however.

    Attached Files:

  2. jcsd
  3. Jul 11, 2008 #2
    Anyone have any ideas?
  4. Jul 11, 2008 #3


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    Homework Helper

    Have you learnt Lenz law yet? You only need a qualitative understanding of it to answer the question. Note that you need a change in magnetic flux through the loop to induce a current. Since you're not given the velocities of the magnet or loop, I think you can assume that their magnitudes are all the same.
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