A Level Physics Practice Exam

What term is used to describe a maximum on a standing wave?

1. Crest

2. Trough

3. Node

4. Antinode

The correct answer is: Antinode

In the context of standing waves, the term that describes a maximum is "antinode." An antinode is a point on the standing wave where the amplitude is at its highest. This occurs because at these points, constructive interference takes place, where the waves traveling in opposite directions reinforce each other. As a result, the displacement of the medium at an antinode is maximized, leading to a peak in the waveform. In contrast, a crest refers specifically to the highest point of a transverse wave, and while it may coincide with an antinode in a standing wave scenario, it is not the general term used for standing waves specifically. A trough, on the other hand, represents the lowest point of a wave, and a node is a point along a standing wave where the medium does not move at all due to destructive interference, thus having zero amplitude. Therefore, antinode is the most precise term to describe the maxima in the context of standing waves.