which part of the wave is changed when there is interference? the amplitude the crest the trough the wavelength

The part of the wave that changes during interference is the amplitude.

Quick Scoop

When two waves interfere (add together), they affect how tall or deep the wave is at each point, which is the amplitude.

• In constructive interference , crests line up with crests and troughs with troughs, so the amplitudes add and the resulting wave is larger.

• In destructive interference , crests line up with troughs, so the amplitudes subtract and can even cancel to zero.

The crest , trough , and wavelength are not fundamentally changed by interference itself; what is changing at each point is how large the displacement becomes, i.e., the amplitude.

So for the multiple-choice question
“Which part of the wave is changed when there is interference?
the amplitude, the crest, the trough, the wavelength”
the correct answer is: the amplitude. ✅

TL;DR: Interference changes how big the wave is at each point, not the spacing between crests and troughs, so the amplitude is what changes.

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