Question

If a beam passes from a material with a refractive index of 1.3 into a material with a refractive index of 1.7 at an angle of 25 degrees (from normal), what is the angle of refraction of the beam? Is the beam bent towards normal or away from it? Sketch a diagram of this problem with rays, angles, and the interface labeled.

Answer 1

18.86° , it will bend towards normal.

Step-by-step explanation:

For refraction,

Using Snell's law as:

`n_i* {sin\theta_i}={n_r}*{sin\theta_r}`

Where,

`{\theta_i}` is the angle of incidence ( 25.0° )

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

`{n_r}` is the refractive index of the refraction medium (n=1.7)

`{n_i}` is the refractive index of the incidence medium ( n=1.3)

Hence,

`1.3* {sin\ 25.0^0}={1.7}*{sin\theta_r}`

Angle of refraction =
`sin^(-1)0.3232` = 18.86°

Since, the light ray is travelling from a material with a refractive index of 1.3 into a material with a refractive index of 1.7 or lighter to denser medium, it will bend towards normal.

The diagram is shown below: