Question

Alex is doing an experiment with a white laser light inside a dark lab.
(i) Explain the phenomenon of dispersion that he will observe when passing the white light through a glass prism, using suitable ray diagram.

Answer 1

When ray of white light enters a prism, it bends because of refraction of light. When the ray of light finally emerges out of the prism, it deviates from its original path. This happens because different colours in the visible spectrum have different speeds. Due to this, different colours bend at different angles of deviation. As a result, the emergent light appears as a band of seven colours: the colours which are the components of white light. These colours are Violet. Indigo, Blue, Green, Yellow, Orange and Red. [1 Mark]
Segregation of white light into its different components is called dispersion of light.
[1 Mark]
[1 Mark]