Question

Light is incident from air on the surface of a glass slab, which has an index of refraction of 2.5 In the air the light beam makes an angle of 35 degree with the normal to the surface. What is the angle of the beam with the normal in the glass?

Answer 1

Answer:

13.26°

Explanation:

Using Snell's law as:

$n_i\times {sin\theta_i}={n_r}\times{sin\theta_r}$

Where,  

${\theta_i}$  is the angle of incidence  ( 35.0° )

${\theta_r}$ is the angle of refraction  ( ? )

${n_r}$ is the refractive index of the refraction medium  (glass, n=2.5)

${n_i}$ is the refractive index of the incidence medium (air, n=1)

Hence,  

$1\times {sin35.0^0}={2.5}\times{sin\theta_r}$

Angle of refraction= sin⁻¹ 0.2294 = 13.26°.

13.26° is the angle of the beam with the normal in the glass.