A prism has refractive index 1.50. What is the miniμm prism angle for a ray entering normally through the first face to undergo TIR at the second face?
Options

Question

A prism has refractive index 1.50. What is the miniμm prism angle for a ray entering normally through the first face to undergo TIR at the second face?

G1 Physics · Accepted Answer

Normal entry gives second-face incidence=A. TIR requires A>C=sin⁻¹(1/1.5)=sin⁻¹(2/3).