As the generator shown turns, an a.c. electromotive force (e.m.f.) is produced across the resistor between points P and Q. Diagram 1 indicates the coil’s position at time $t = 0$. The coil rotates clockwise. By time $t_1$, the coil is horizontal, as shown in diagram 2. The graph plots the output e.m.f. between points P and Q against time. Which point represents the e.m.f. at time $t_1$?
Physics 0625 · IGCSE · Electromagnetic effects