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Homework Help: Direction of induced EMF in loop

  1. Apr 14, 2015 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    Faraday's and Lenz' law.

    emf = -d(ф)/dt
    3. The attempt at a solution
    The current is increasing upwards during that time interval.
    Thus, by Right-Hand-Rule, the magnetic field goes into the page at the loop.
    Lenz' law says that the loop's induced emf will produce a magnetic field that opposes the field from the wire.
    Thus a magnetic field in the opposite direction, out of page, would mean, by RHR, that the induced emf is counter-clockwise.

    This is however not the answer. Which one of the above statements is flawed?

    Thank you very much.
  2. jcsd
  3. Apr 14, 2015 #2
    Draw the graph of sin2πt and check if it increases from 0.25 to 0.3
  4. Apr 15, 2015 #3
    Oh I understand that it decreases actually. I had only punched sin (2pi(0.28)) into a calculator and it gave me a positive. Thank you.
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