Question

Why monochromatic light os used for double slit rxperiment to find the grating element?

Answer 1

Answer:

Monochromatic light is light of a single color; by use of such light, the two sources will vibrate with the same frequency. It is also important that the two light waves be vibrating in phase with each other; that is, the crest of one wave must be produced at the same precise time as the crest of the second wave.