n the figure given below a narrow beam of white light is shown to pass through a triangular glass prism.

Question

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

 

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

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

Answer 1

(i) X – Violet 

Y – Red 

(ii) This happens due to the following reasons: 

(a) Due to difference in speed of different colours 

(b) Due to difference in wavelength and frequency 

(c) Due to refractive index of glass is different for different colours of light.