Constructive interference
When two waves meet which are in phase, their amplitudes add together to create a wave with a larger amplitude. That’s called constructive interference.
If the phase difference between the two waves is zero or a multiple of 360°, the waves are in phase. That means that the peaks of one wave line up exactly with the peaks of the other wave, and the troughs line up exactly with the troughs. When this happens, the amplitudes of the two waves add together to create a new wave with a larger amplitude.
For example, if two waves each have an amplitude of 2 units, when they interfere, they will interfere constructively to create a new wave with an amplitude of 4 units.
flashcards
| Question | Answer |
|---|---|
| Constructive interference | When two waves that are in phase meet, their amplitudes add to produce a wave with larger amplitude. |
| How must two waves be related for constructive interference to occur? | They must have a phase difference of zero or a multiple of |
| What alignment of peaks and troughs happens during constructive interference? | The peaks of one wave line up exactly with the peaks of the other, and the troughs line up exactly with the troughs. |
| If two waves each with amplitude 2 units interfere constructively, what is the resulting amplitude? | 4 units. |