How many colours are there in a full spectrum of white light? Write the various colours of spectrum in the order, starting with red.

When a beam of white light is passed through a prism, it splits to form lights of seven colours. Is it possible to recombine the lights of seven colours to obtain the white light again? Explain your answer.

What is spectrum? What is the name of glass shape used to produce a spectrum?

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

In the figure given alongside, a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism, it produces a spectrum YX on the screen.

(a) State the colour seen (i) at X, and (ii) at Y.

(b) Why do different colours of white light bend through different angles with respect to the incident beam of light?