1.1 Principle of superposition

1.1 Principle of superposition

2.1 Relation between phase difference $\left( \phi \right)$ and path difference $\left( {\Delta x} \right)$
2.2 Interference of waves from coherent sources
2.3 Interference of waves from incoherent sources
2.4 Reflection and transmission of a wave
2.5 Motion of wave during reflection
2.6 Expression for the reflection and transmission of wave

3.1 Transverse stationary wave on a stretched string
3.2 Vibrations in a stretched string
3.3 Melde's Experient
3.4 Resonance

4.1 Open organ pipe
4.2 Closed organ pipe
4.3 End correction
4.4 Resonance tube
4.5 Energy in a stationary wave

It states that when two or more waves travel in a medium in such a way that each wave represents its separate motion individually, then the resultant displacement of the particle of the medium at any time $t$ is equal to the vector sum of the individual displacements.

If ${y_1},{y_2}...{y_n}$ are the displacement at a point due to $n$ waves, then the resultant displacement $(y)$ at that point is given by, $$y = {y_1} + {y_2} + ... + {y_n}$$

Note: Principal of superposition holds true for all type of waves, provided the waves are not of very large amplitude.

The superposition of waves give rise to the following three phenomena.