what is a rainbow ? What is the essential condition for observing it ?

What is the essential condition for observing rainbow ?

What is the essential condition for observing a rainbow?

What is rainbow?

What is the essential condition for the formation of beats ?

What is the essential condition for the formation of beats?

A rainbow is an example of dispersion of sunlight. Justify this statement by explaining, with a neat labelled diagram, the formation of a rainbow in the sky. List two essential conditions for observing a rainbow.

(a) Why do spectrum colours recombine on passing through two prisms oriented duly ? (b) What is the essential condition for observing a rainbow ?