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Homework Help: Magnetoelectric induction, I think

  1. Jun 7, 2009 #1
    1. The problem statement, all variables and given/known data

    All I've been given concerning this problem is the diagram below and the instruction to solve for the total voltage at both voltmeters.

    Unfortunately, I am not sure whether this configuration counts as a electromagnetic coil, or whether it is simply two single-wire circuits, one for each voltmeter, connected at Points A and B. It also isn't clear from the diagram whether voltmeter #1, and its associated circuit, is in the same plane as the other voltmeter.

    The known data:
    radius = .1m (A = .01pi)
    magnetic flux density = 100w/m^2 or 100 Teslas
    frequency = 1000 kHz

    2. Relevant equations

    I have been assuming that this each circuit is a coil (with one turn) and that I can use Faraday's Law: EMF = dphi/dt

    where phi = the magnetic flux = B*A*cos(theta)

    3. The attempt at a solution

    Quite frankly, I'm stuck. I'm not sure what 'theta' represents. B*A = 100w/m^2*.01m^2*pi = pi webers, so flux = pi * cos(theta). Is theta the angle of the coil? And once I get phi, how to I use Faraday's Law?

    Attached Files:

    Last edited: Jun 7, 2009
  2. jcsd
  3. Jun 8, 2009 #2
    I am not sure about the diagram, but since they say that the magnetic field is a sine wave, the magnetic field B must vary with time. Write B as a function of time.
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