Question

A light ray is incident on a plane surface separating two transparent media of refractive indices of 1.65 and 1.35. If the incident angle is 35º and the light ray originates in the medium of higher refractive index. (a) Compute the angle of refraction. (b) Repeat part (a), assuming that the light ray originates in the medium of lower refractive index.

Answer 1

Explanation:

Given

Refractive Index $(n_1)=1.65$

$n_2=1.35$

angle of incident$=35 ^{\circ}$

Light originates in the medium of higher refractive index

Let $\theta _1$ and $\theta _2$be the incident and refraction angles respectively  thus according to snell's law

$n_1sin\theta _1=n_2sin\theta _2$

$1.65\times sin35=1.35\times sin\theta _2$

$sin\theta _2=0.701$

$\theta _2=44.507^{\circ}$

(b)Ray originates from lighter medium

$1.35\times sin35=1.65\times sin\theta _2'$

$sin\theta _2'=0.469$

$\theta _2'=27.96\approx 28^{\circ}$