A loop of current-carrying wire has a magnetic dipole moment of 5 * 10^-⁴ A . m². The moment initially is aligned with a 0.5-T magnetic filed.To rotate the loop so its dipole momentt is perpendicular to the field and hold it in that orentation, you must do work of: A) 0 B) 2.5* 10^-⁴ J C) -2.5 * 10^-⁴ J D) 1.0 * 10^-³ J E) -1.0 * 10^-³ J

Question

Quizplus · Accepted Answer

The work done to rotate a magnetic dipole moment from an alignment with a magnetic field to a perpendicular orientation is given by ΔU = -m • B, where m is the magnetic dipole moment and B is the magnetic field. In this case, ΔU = - (5 x 10^-10 Nm) • (0.5 T) = - 2.5 x 10^-10 J, which is option B.

A Loop of Current-Carrying Wire Has a Magnetic Dipole Moment