See http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magmom.html
Torque = 6*Area*B*sin 90 = 6 pi*a*b*B
The coil area gets multiplied by 6 because of the number of loops
An eight turn coil encloses an elliptical area having a major axis of 40.0 cm and a minor axis of 30.0 cm. The coil lies in the plane of the screen and has a 6.10 A current flowing clockwise around it. If the coil is in a uniform magnetic field of 2.07 10-4 T directed toward the left of the screen, what is the magnitude of the torque on the coil? (Hint: The area of an ellipse is A = πab, where a and b are, respectively, the semimajor and semiminor axes of the ellipse.)
2 answers
.000468