Question

Material $1$ has an index of refraction of $1.15$.
Material $2$ has an index of refraction of $2.30$.
If light passes from air into each of these materials at the same angle of incidence, how will the angle of refraction in material $1$ compare to the angle of refraction in material $2$?

• A. The angle of refraction in material $1$ will be half as much as the angle of refraction in material $2$
• B. The angle of refraction in material $1$ will be greater than the angle of refraction in material $2$
• C. The angle of refraction in material $1$ will be less than the angle of refraction in material $2$ but not necessarily half as much as the angle of refraction in material $2$
• D. The angle of refraction in material $1$ will be less than the angle of refraction in material $2$ but not necessarily twice as much as the angle of refraction in material $2$
• E. The angle of refraction in material $1$ will be one-fourth as much as the angle of refraction in material $2$

Answer 1

Answer: (B)

The angle of refraction in material $1$ will be greater than the angle of refraction in material $2$

$n_1$=$1.15$ $n_2$ =$2.30$

Given : $n_1<n_2$

Refractive index of air $n_a=1.00$

Using Snell's law of refraction, $n_{air}\times sini=n_{medium}\times sinr$

$\therefore$ $1.00\times sini=n_{medium}\times sinr$ $⟹$ $sinr=\frac{sini}{n_{medium}}$

Hence $r$ is inversely proportional to refractive index $n$

Thus $n_1<n_2$ $⟹$ $r_1>r_2$