CAIE IGCSE Physics Generator EMF-Time Graphs
Practise sketching sinusoidal generator output, matching coil positions to peaks and zeros and predicting amplitude or frequency changes as rotation changes.
- Syllabus
- 2026–2028
- Course
- Physics 0625
Practise sketching sinusoidal generator output, matching coil positions to peaks and zeros and predicting amplitude or frequency changes as rotation changes.
Fig. 10.1 shows a simple alternating current generator.

Fig. 10.1
On Fig. 10.2, sketch a graph to show how the electromotive force (e.m.f.) induced varies with time for one revolution of the coil. Assume that the coil starts in the horizontal position, as shown in Fig. 10.1.
Label the points on the time axis where the coil has completed 1 / 4 revolution and 3/4 revolution.

Fig. 10.2
Correct shape of graph showing one rotation
B1
Graph starts from maximum voltage (positive or negative) (labelled horizontal)
B1
Graph passes through zero twice, labelled 1 / 4 and 3 / 4 revolution
B1