College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 33

An eight-turn coil encloses an elliptical area having a major axis of 40.0 cm and a minor axis of 30.0 cm (Fig. P19.27). The coil lies in the plane of the page and carries a clockwise current of 6.00 A. If the coil is in a uniform magnetic field of 2.00 × 10 4 T directed toward the left of the page, what is the magnitude of the torque on the coil Hint: The area of an ellipse is A = ab , where a and b are, respectively, the semimajor and semiminor axes of the ellipse.