A loop of wire carrying a current of 2.0 A is in the shape of a right triangle with two equal sides, each 15 cm long. A 0.7 T uniform magnetic field is parallel to the hypotenuse. The resultant magnetic force on the two sides has a magnitude of:
A) 0
B) 0.21 N
C) 0.30 N
D) 0.41 N
E) 0.51 N

Question

Quizplus · Accepted Answer

The magnetic force on a current-carrying wire is given by F = I * L * B * sin(θ). Since the magnetic field is parallel to the hypotenuse, it is perpendicular to the equal sides of the triangle, making θ = 90° for these sides. However, the forces on the two equal sides are equal in magnitude and opposite in direction, thus canceling each other out, resulting in a net force of 0.

A Loop of Wire Carrying a Current of 2