Question

How does the angle of minimum deviation of a glass prism vary, if the incident violet light is replaced by red light? Give reason.

Answer 1

Refractive index is inversely proportional to the wavelength of the light. Red has a higher wavelength than violet light therefore it has a smaller refractive index than violet.

Again angle of minimum deviation is directly proportional to refractive index and hence will decrease when replaced by red light.