What are the coherent sources of light ?

What are the coherent source of light ? What are the conditions for obtaining two coherent sources of light ?

What is the difference between coherent and incoherent sources of light?

Define coherent sources of light, fringe width and interference of light. Show that the width of dark fringe is equal to the width of bright fringe in Young's double slit experiment.

What a re the natural sources of light ? name some natural sources of light

What are the sources of water ?

What are the main sources of irrigation?

What is a source of light ?

What is a coherent system of units? Give an example of coherent system of units.

Name three natural sources of light.