← Back to Test

Problem 4 - Entrance Test

A rectangular coil with 100 turns, each of area 0.01 m², is placed in a uniform magnetic field of 0.5 T. If a current of 2 A flows and the coil rotates such that its normal makes a 30° angle with the field, what is the maximum torque?

Correct: C

Torque τ = N I A B sinθ = 100 * 2 * 0.01 * 0.5 * sin(30°) = 0.5 N·m. The maximum torque occurs at θ = 90°, but since the question specifies 30°, calculations must apply the sine factor correctly. Misreading θ or missing N leads to other options.