A flat circular loop of wire is in a uniform magnetic field of 0.30 T.The diameter of the loop is 1.0 m,and a 2.0-A current flows in it.What is the magnitude of the magnetic torque on the loop when the plane of the loop is parallel to the magnetic field?
A)0.00 N ∙ m
B)0.41 N ∙ m
C)0.47 N ∙ m
D)0.52 N ∙ m

Question

Quizplus · Accepted Answer

The magnetic torque on a current loop is given by the formula τ = NIAB sinθ, where N is the number of turns in the loop, I is the current, A is the area of the loop, B is the magnetic field strength, and θ is the angle between the plane of the loop and the direction of the magnetic field. In this case, N = 1, I = 2.0 A, A = πr^2/4 = (π/4)(0.5 m)^2 = 0.20 m^2, and θ = 0° (since the plane of the loop is parallel to the magnetic field). Substituting these values, we get τ = (1)(2.0 A)(0.20 m^2)(0.30 T)(sin 0°) = 0.47 N∙m. Therefore, the correct answer is C.

A Flat Circular Loop of Wire Is in a Uniform