To understand the concept of interference and conditions for sustained interference, let us first discuss the superposition principle.
Superposition principle enables us to find the resultant of two or more wave motions.
According to this principle, when two or more waves travelling through a medium superimpose upon one another, a new wave is formed in which resultant displacement . at any instant is equal to the vector sum of the displacements due to individual
waves . at that instant
For example, when crest (or trough) of one wave falls on crest (or trough) of the other, the amplitude of the resultant wave is sum of the amplitudes of two waves.
When crest of one wave falls on trough of the other, the amplitude of resultant wave is difference of the amplitude of the two waves. Continue reading “6 conditions for sustained inteference”