Question

Ray traveling in air (n = 1) is incident on a flat surface of refractive index n = 1.52. For what angle of incidence are the refractive and reflected rays perpendicular? A ray traveling in vacuum enters a long fiber of refractive index n = 1.5. Show that the ray undergoes total internal reflection for any angle of incidence.

Answer 1

A)

refractive and reflected rays are perpendicular

r + p =90^o

the condition for

n = tan p

1.52 = tan p

p = 56.66^o

B)

n₁*sin$\theta$_c = n₂*sinr

1*sin$\theta$_c = 1.5

sin$\theta$_c = 1.5

not possible

(n₂/n₁) > 1