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

What is the essential condition for observing rainbow ?

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

Why do different colours deviate through different angles on passing through a prism ?

Why do you not see a spectrum of colours when light passes through a flat pane of glass ?

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.

Why white light splits into different colours when it passes through a prism ?

While passing through a prism, why does the white light split into seven colours.