Interference: The combined result of two or more wave trains traveling in parallel or coincident directions. The result is the result of adding the individual wave amplitudes at each place that is influenced by multiple waves. interference.
Diagram of destructive interference:
The dark margins are due to destructive interference. Interference is referred to as destructive if the subsequent amplitude and, hence, the subsequent intensity are both zero. In order for destructive interference to take place, both the path difference and phase difference between the two waves must be odd multiples of .
Destructive interference happens when the maxima of two waves are degrees out of phase; a positive displacement of one wave is precisely cancelled by a negative displacement of the other wave. Zero amplitude is the resultant wave.
Hence, The dark patches show up when the waves collide destructively.
