What is the cause of dispersion of white light through a glass prism Draw a ray diagram to show the path of light when two identical glass prisms are arranged together in inverted position with respect to each other and narrow beam of white light is allowed to fall obliquely on one of the faces of the prisms.

Explanation

The phenomenon of splitting of white light into seven colurs on passing through a glass-prism is called dispersion of white light. Refraction of light is the cause of dispersion of white light into its seven component colurs by a prism. The dispersion of white light occurs because colours of white light travel at different speeds through the glass prism. Different colours of light bend through different angles with respect to the incident ray as they pass through a prism.