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Homework Help: Magnetic field of circular loop

  1. Oct 11, 2011 #1
    1. The problem statement, all variables and given/known data
    Two small identical circular loops carrying equal currents are placed with the geometrical axis perpendicular to each other. Find the magnitude and direction at a point O at an equal distance x from their centers.

    2. Relevant equations
    Magnetic field of a current carrying circular loop at a distance x on it's axis : μIR2/2x3 when x>>>R

    3. The attempt at a solution
    Let μIR2/2x3 = B
    Then magnitude should be (21/2)B(Fields perpendicular to each other)
    Inclined at an angle 45° with the horizontal.

    Are my directions right?

    Attached Files:

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    Last edited: Oct 11, 2011
  2. jcsd
  3. Oct 11, 2011 #2
    Your equation for the magnetic field seems like it's missing a factor of 2 in the denominator. Also, check your vector addition when adding the magnitudes of the fields.
  4. Oct 11, 2011 #3


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    Directions look right, although, it's hard for the viewer to be certain of the direction of current flow.

    B1/2 is not correct. That's the square root of B.
  5. Oct 11, 2011 #4
    Sorry about that. I meant, (21/2)B (I don't know how to make the squareroot symbol here) And yes, the equation was missing a 2. Typo again.
    I don't have any problems with the magnitude. Just the direction. The solution in my book has a direction opposite to the one I got.
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