A 0.3-m long wire carries 10 A of current as shown.If the magnetic force F on it is 3 N,what is the magnitude and direction of the field?

Question

Quizplus · Accepted Answer

The magnetic force F on a wire is given by F = BILsinθ, where B is the magnetic field, I is the current, L is the length of the wire, and θ is the angle between the wire and the magnetic field. In this case, F = 3 N, I = 10 A, and L = 0.3 m. Since the wire is perpendicular to the magnetic field (θ = 90°), sinθ = 1. Solving for B, we get B = F/IL = 3 N / (10 A * 0.3 m) = 1 T. The direction of the magnetic field can be determined using the right-hand rule: if you point your right thumb in the direction of the current (to the right in this case) and curl your fingers, the direction of the magnetic field is into the paper. Therefore, the answer is D.

A 03-M Long Wire Carries 10 a of Current as Shown