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Homework Help: Physics Home work question

  1. Feb 14, 2006 #1
    I have no idea where to stat on this question.

    A magnetic field is perpendicular to a 0.040 m 0.080 m rectangular coil of wire that has 110 turns. In a time of 0.040 s, an average emf of magnitude 2.0 V is induced in the coil. What is the magnitude of the change in the magnetic field?

    Can anyone help me out?
     
  2. jcsd
  3. Feb 14, 2006 #2

    berkeman

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    Staff: Mentor

    What equation relates the change in magnetic flux to the voltage induced in a single turn of wire? The answer is just 110 times that, since the closed loop integral can follow the path of the 110 spiralling turns, and then return back down to connect to the start of the coil.

    Remember, a current in a wire causes a magnetic field (see Biot-Savart), and a changing magnetic field/flux through a loop causes an induced emf or voltage (who's law?).
     
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