Question

A ray of light in air is incident to an air-to-glass boundary at an angle of exactly 30° with the normal. If the index of refraction of the glass is 1.65, what is the angle of the refracted ray within the glass with respect to the normal?

Answer 1

In order to calculate the angle of the refracted ray, we can use the law of refraction (Snell's Law) below:

`(\sin\theta_1)/(\sin\theta_2)=(n_2)/(n_1)`

Where n1 and n2 are the indexes of refraction and theta1 and theta2 are the angles of the ray.

So, using n1 = 1, n2 = 1.65 and theta1 = 30°, we have:

`\begin{gathered} (\sin30°)/(\sin\theta_2)=(1.65)/(1)\\ \\ ((1)/(2))/(\sin\theta_2)=1.65\\ \\ \sin\theta_2=((1)/(2))/(1.65)=(1)/(3.3)=0.303\\ \\ \theta_2=17.64° \end{gathered}`