Question

A ray is incident at an angle of incidence i on one surface of a prism of small angle A and emerges normally from the opposite surface. If the refractive index of the material of the prism is m, the angle of incidence i is nearly equal to –

• A. A/m
• B. A/2m
• C. mA
• D. mA/2

Answer 1

Answer: (C)

mA

Answer 2

Since the ray emerges normally therefore e = 0, r₂ = 0

Q r₁ + r₂ = A, r₁ = A

for thin prism m = =

i = mr_1, i = mA

option (3) is correct.