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Homework Help: Square loop of wire surrounding a solenoid

  1. Mar 3, 2010 #1
    A square loop of wire surrounds a solenoid. The side of the square is 0.1 m, while the radius of the solenoid is 0.025 m. The square loop has a resistance of 30 W. The solenoid has 500 turns and is 0.3 m long. The current in the solenoid is increasing at a constant rate of 0.7 A/s. What is the current flowing in the square loop?

    e = -DFB/Dt = A*DB/Dt
    e = A*(m0nDI)/Dt

    I cannot figure out what the area the equation is talking about. I substituted 500 for n and .7 for change in I over change in T but the area i have which i thought was .001m^2 i don't think is right. help!
  2. jcsd
  3. Mar 4, 2010 #2
    The area is the area inside the solenoid, since this is the only place where there is an external magnetic field.
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