# Homework Help: Magnetic field of circular loop

1. Oct 11, 2011

### Qaztgbe

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?

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Last edited: Oct 11, 2011
2. Oct 11, 2011

### DukeLuke

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.

3. Oct 11, 2011

### SammyS

Staff Emeritus
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.

4. Oct 11, 2011

### Qaztgbe

!
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.