(b) For any given thin prism of small angle \( A \), refractive index \( n \), and an incident blue light, answer the following questions.
i. Write the formula for angle of minimum deviation for a thin prism. If the whole arrangement is immersed in a liquid of refractive index \( n \) ' \( < n \), how will the angle of minimum deviation change?
ii. For some angle of incidence on the second face of the prism, the incident blue light undergoes total internal reflection. However, a red incident light for the same angle of incidence on the second face of the prism does not undergo total internal reflection. Give reason.
[3 marks]
