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Homework Help: Calculate the potential difference induced in the circuit as a function of time

  1. Jul 23, 2011 #1
    1. The problem statement, all variables and given/known data

    A square circuit with side L lies in the x-y plane, is centred on the origin and has sides parallel to the x and y axes. At time t=0 it starts turning about the x axis, in a region characterised by a uniform magnetic field B parallel to z, with uniform angular speed omega. By considering the angle between the surface normal and the field, calculate the potential difference (electromotive force) induced in the circuit as a function of time.

    2. Relevant equations

    phi(subscript B)=BA cos theta

    potential difference=-d(phi (subscript b))/dt

    3. The attempt at a solution

    potential difference=-d(BA cos theta)/dt

    this isn't leading anywhere. I don't know how to differentiate it with respect to t
  2. jcsd
  3. Jul 23, 2011 #2
    You need to express the angle theta (angle between surface normal and field lines) in terms of time. (theta starts from 0 degrees)
    Last edited: Jul 23, 2011
  4. Jul 23, 2011 #3
    thank you, Pi-bond

    potential difference=-d(BA cos omega*t)/dt

    =BA omega sin (omega*t)

  5. Jul 23, 2011 #4
    Yes, that is correct.
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