A boy uses blue colour of light to find the refractive index of glass

A boy uses blue colour of light to find the refractive index of glass. He then repeats the experiment using red colour of light. Will the refractive index be the same or different in the two cases? Give a reason to support your answer.

Answer

Refractive index will be different.

a𝜇g= sin 𝑖⁄ sin 𝑟, different colours will have different angle of refraction even if the angle of incidence is the same therefore refractive index will be different. OR Speed of red colour and blue colour of light in air or vacuum is the same but in glass it is different. So refractive index of glass will be different as aµg=𝑐𝑎/𝑐𝑏.