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Homework Help: Moving Square

  1. Jan 25, 2004 #1
    A square conducting loop with sides a lies on a table a distance s from a very long straight wire carryinga current I.

    a) Derive an expression for the magnetic flux through the loop.

    b) Derive an expression for the EMF induced in the loop if it is pulled away in a direction orthogonal to the wire at speed v.

    c) Derive an expression for hte EMF induced in the loop if it is pulled away in a direction parralel to the wire at speed v.

    I know that I have to use Ampere' s Law to calculate the magnetic field but am not sure how to do this correctly and how will the field help to calculate the flux?
  2. jcsd
  3. Jan 25, 2004 #2
    s is the distance between the the side of the square closest to the wire and the wire

    I am able to calculate part a) now after having worked on it for a while...Phi = (mu0Ia/2Pi) * ln((s+a)/a)

    c) According to me since s does not change there is no change in the magnetic field through the loop when the loop is moved parallel to the wire and so there should be no change in phi and so no dPhi/dt or no EMF...Is this explanation correct?

    I need some major help with part b) please someone..I think that I have made a significant effort and now need just help with that part to solve the question.....any feedback would be great.
  4. Jan 25, 2004 #3
    Come on guys...something...pleeease!
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