A 45°-45°-90° prism is used to turn a normally incident ray through 90° by TIR at the hypotenuse. Miniμm prism refractive index is:
Options

Question

A 45°-45°-90° prism is used to turn a normally incident ray through 90° by TIR at the hypotenuse. Miniμm prism refractive index is:

G1 Physics · Accepted Answer

Internal incidence at hypotenuse is 45°. TIR requires C≤45°, so μ≥√2.