Page 37 - WAVES

Interference of Waves

Constructive Interference Destructive Interference

Constructive interference occurs when two Destructive interference occurs when two

waves at same phase (two crests or two waves at out of phase (crest of one wave with
troughs) coincide to produce a wave with the trough of the other wave) coincide, thus

crests and troughs of maximum amplitude canceling each other with the result that the
(+2a or -2a). resultant amplitude = 0.

Keys : Antinode
• Maximum crest wave (2 crests meet)
× Zero amplitude (trough meets crest) A point where constructive
о Maximum trough wave (2 troughs meet) interference occurs.

Node line Antinode line Node

A point where destructive
interference occurs.

Wavefront (troughs)

Wavefront (crests)

S 2 Waves sources S 1 37