A rectangular loop of wire whose dimensions are 15 cm * 25 cm carries a current of 5.0 A. The loop is in a uniform magnetic field of 1.5 T whose direction is perpendicular to the plane of the loop. The torque acting on the loop is
A) zero.
B) 0.24 N·m.
C) 0.28 N·m.
D) 0.35 N·m.

Question

Quizplus · Accepted Answer

The torque on a loop in a magnetic field is given by τ = nIABsinθ. Here, θ = 90° (since the field is perpendicular), so sinθ = 1. The area A = 0.15 m * 0.25 m = 0.0375 m². Thus, τ = 1 * 5.0 A * 0.0375 m² * 1.5 T * 1 = 0.28125 N·m. However, since the field is perpendicular, the torque is zero.

A Rectangular Loop of Wire Whose Dimensions Are 15 Cm