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Homework Help: Magnetic field and current

  1. Oct 1, 2008 #1
    1. The problem statement, all variables and given/known data

    A current of 6.1 A is maintained in a single circular loop having a circumference of
    110 cm. An external magnetic field of 5.5 T is
    directed such that the angle between the field
    and the plane of the loop is 42◦.
    Determine the magnitude of the torque exerted on the loop by the magnetic forces acting upon it.
    Answer in units of N · m.

    2. Relevant equations

    torque = N*I*A*B*sin(theta)



    3. The attempt at a solution

    = 0.17507 m

    =pi*(0.17507 m)^2
    =0.096288 m^2

    torque = 1 loop * 6.1 A * 0.096288 m^2 * 5.5 T * sin(42)
    = 2.1616 N*m
  2. jcsd
  3. Oct 1, 2008 #2


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    Homework Helper

    Hi Kris1120,

    I believe you make an error later in applying this equation. What does the theta in this equation represent?
  4. Oct 5, 2008 #3
    Oh I have to subtract theta from 90! Thanks!
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