Determine the torque acting on the rectangular loop of height l and width w in a constant external magnetic field B~ shown below with angle θ between the area vector and theexternal magnetic field. Show that the torque can be written as τ = m × B, where m = Ia is called magnetic dipole moment, I is the current in the loop, and a = wln is area vector for the area bounded by the loop. For this problem, take B = Bx and the sides of length l to be parallel and n perpendicular to the z-axis.

Determine the torque acting on the rectangular loop of height l and width w in a constant external magnetic field B~ shown below with angle θ between the area vector and theexternal magnetic field. Show that the torque can be written as τ = m × B, where m = Ia is called magnetic dipole moment, I is the current in the loop, and a = wln is area vector for the area bounded by the loop. For this problem, take B = Bx and the sides of length l to be parallel and n perpendicular to the z-axis.