A ray of light is directed towards a prism as shown - Edexcel - A-Level Physics - Question 8 - 2023 - Paper 2

Snell's law states that: $n_1 imes ext{sin}( heta_1) = n_2 imes ext{sin}( heta_2)$ In this case,

• Let $n_1 = 1$ (air) and $n_2 = 1.5$ (prism material).
• $heta_1 = 30°$.

We calculate: $1 imes ext{sin}(30°) = 1.5 imes ext{sin}( heta_2)$ Solving for $heta_2$ allows us to find the angle at which the light refracts into the prism.

The initial entry of light from point A to B will bend towards the normal inside the prism. It will then hit the second boundary at point C and, due to the higher index of refraction of the prism, it will bend away from the normal upon exit.

Based on the refraction analysis, the line that accurately represents the light's path is option C. This path illustrates the correct comprehension of refraction, showing the light bending towards the base of the prism before exiting.