Question

What is meant by coherence?

Answer 1

1. Coherence represents the relationship between waves.
2. When two waves have a constant relative phase or a zero or constant phase difference and the same frequency, they are said to be coherent.
   
3. All characteristics of the correlation between the physical components of a single wave, or between multiple waves or wave packets, are referred to as coherence.
4. If the relative phase of two waves remains constant, the waves are said to be coherent.
5. The characteristics of the coherence are:
   5.1 The waves have a constant phase difference
   5.2 The waves have a single frequency.