Question

What is the difference between constructive and destructive interference?

Answer 1

In constructive interference, a crest meets a crest or a trough meets a trough, resulting in a larger crest or trough. Re-inforcement occurs and the resultant amplitude is the algebraic sum of each waves amplitude.

In destructive interference, a crest meets a trough and results in cancellation hence a smaller disturbance than either of the two interacting waves.