A monochromatic ray of light is incident on a thin triangular prism kept in air

PHYSICS · Multi-part · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments

Problem

A monochromatic ray of light is incident on a thin triangular prism kept in air. The prism has a small apex angle

A

(in radians) and is made of a material of refractive index

\mu

for the given wavelength. (i) Derive an expression for the angular deviation

d

suffered by the ray in terms of

\mu

and

A

under the approximations that

A

is small and the angles of incidence and refraction are small enough for

\sin \theta \approx \theta

(in radians). (ii) A glass prism has an apex angle of

3^{\circ}

. For green light, the refractive index of the glass is

1.52

. Calculate the approximate deviation produced by the prism for this light, expressing your answer in degrees.