Electromagnetic Induction: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Electromagnetic Induction. Understanding the underlying formula is key to arriving at the correct answer below:

The induced emf in a rotating loop varies sinusoidally as $e = e_0 \sin(\omega t)$.
In one complete revolution ($2\pi$ radians), the sine function alternates between positive and negative half-cycles.
Thus, the direction of the induced e.m.f. reverses twice per revolution.