µ=√2,A=90∘ For total internal reflection siniC=
1
µ
=
1
√2
=sin45∘ ∴iC=45∘ For total internal reflection to occur at the second face, the angle of incidence at the second face ( r2 ) must be greater than or equal to the critical angle. To ensure total internal reflection, we consider the limiting case where r2=θc=45∘ The angle of the prism is related to the angles of refraction at the two faces by A=r1+r2 Since A=90∘ and r2=45∘ 90∘=r1+45∘ r1=90∘−45∘=45∘ Applying Snell's law at the first face, µair sini=µprism sinr1 1⋅sini=√2sin45∘ sini=√2⋅
