What is meant by interference? Explain.
In simple words, interference is the addition of two or more waves meet at point that results in a new wave pattern.
When two or more waves are passing through a medium, the net displacement of the wave is given by vector sum of the displacement caused by all the waves. The principle of taking vector sum is known as superposition of waves. It can be both constructive and destructive.
The points at which waves arrive in phase (phase difference = 0), maximum displacement is observed which is called constructive interference. When the two waves arrive at a point such that they are out of phase (phase difference = π), minimum displacement is observed, which is called destructive interference.