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Homework Help: Electromagnetism Question

  1. Jan 16, 2007 #1
    1. The problem statement, all variables and given/known data
    A loop of wire of aream 0.32m^2 is palced in a 0.75 T magnetic field. The magnetic field is changed to 0.35 T in the opposite direction in 0.45 s . What is the magnitude of the current through the 15 ohm resistor.


    2. Relevant equations
    emf = -N (flux / time)


    3. The attempt at a solution

    emf = (-1) [(.35T)(.32m^2)-(.75T)(.32m^2)]/(.45s)
    emf = .284 V
    V = IR
    I = .284 V / 15ohm
    I = .019 A

    .019 is the wrong answer in the multiple choice
    the correct answer is supposed to be 0.052 A

    Thanks
     
  2. jcsd
  3. Jan 17, 2007 #2

    OlderDan

    User Avatar
    Science Advisor
    Homework Helper

    Looks like you have not computed the change in field correctly.
     
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