Dispersion of White Light by a Glass Prism

A narrow beam of white light enters a glass prism and it splits into the colours of the visible spectrum. The lines labelled A to G represent rays of seven main colours of the visible spectrum. Write down the letter that corresponds to the YELLOW ray.

How will you use two identical glass prisms so that a narrow beam of white light incident on one of the prisms emerges out of the second prism as a beam of white light? Draw a labelled diagram to illustrate it.          

Which of the following colour of white light is least deviated by the prism?

What is meant by the dispersion of white light? Describe the formation of the rainbow in the sky with the help of a diagram.

What did Newton demonstrate by his experiments with the prism?