Which of the following pairs of light rays shows the widest separation in the spectrum of white light?
Red and blue
Orange and green
Red and indigo
Violet and green
Yellow and red
Correct answer is C
This is called dispersion . A beam of white light passes through a prism and changes into a spectrum of colours.
The spectrum is a band of seven colours which is obtained by splitting of white light by a glass prism. The order of colours from the lower end of spectrum is violet (V), indigo (I), blue (B), green (G), yellow (Y), orange (O), and red (R).