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Homework Help: Current produced by varying magnetic flux

  1. Jun 29, 2011 #1
    I'm translating the problem, so sorry for the errors.

    1. The problem statement, all variables and given/known data
    Radius of the upper circumference = 5cm
    Radius of the lower circumference = 9cm
    Resistance/meter = 3.00 ohm/meter
    B is the magnetic field: DB/dt = 2.00 T/s

    What's the magnitude of the current, and where does the current points to?

    2. Relevant equations

    EMF = [itex]-N \ \frac{\Delta \Phi_B}{\Delta t} \ \ \mbox{or} \ \ -N \ \frac{d\Phi_B }{dt}[/itex]
    V = RI

    3. The attempt at a solution
     

    Attached Files:

    Last edited: Jun 29, 2011
  2. jcsd
  3. Jun 29, 2011 #2
    Well, find the magnetic flux from the external field; the current should be produced in order to oppose an change in magnetic flux.
     
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