Define superposition principal ?

Answer

Superposition principle
When two or more than two trains of waves travel in a medium at time each train of wave proceeds in dependently, as if the other trains of waves are in absent. The displacement of the particle at any instant of time due to these waves is totally independent of one another and can be obtained by the vector sum of the individuals displacements. Such a process by which the different trains of waves travelling through a medium simtultaneously overlap. one another without losing their individual nature or shape in called superposition of waves.