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Homework Help: Induced EMF

  1. Sep 22, 2005 #1

    WY

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    Hey
    I'm wondering if someone can help me out with this question.

    Q: In order to measure the magnetic fields produced by the power lines carrying 50Hz alternating current, a coil consisting of 1500 turns of area 5cm^2 as constructed. Suppose that there is a single power line carrying a current which has an amplitude of 800A and that the coil is 10m from the wire.
    a) What is the magnitude of the magnetic field at the coil
    I found this using B =[N(mu_0)I]/2R
    b) What is the magnitude of the induced emf in the coil?

    I'm stumped on B :confused: could anyone point me in the right direction? I was using the idea that change in flux over time can be used to find induced emf and that in an alternating curret dI/dt=2*pi*f*I - but the problem is that i don't know where to go from there.

    Thanks in advance!
     
  2. jcsd
  3. Sep 22, 2005 #2

    mukundpa

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    Homework Helper

    The magnetic field is not constant.
    Write the equation for the current as a function of time.
     
  4. Sep 22, 2005 #3

    WY

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    thanks for the quick reply - but i don't quite understand how this ties in with finding the emf using the change in flux over the change in time.
     
  5. Sep 22, 2005 #4

    WY

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    oh i see now! sorry - I wasn't thinking properly! Thanks again :)
     
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