Physics · May / June 2023 · Paper 11 · Question 21

A ray of light is incident on a plastic block in air, at an angle of incidence i. The refractive index of the plastic is n. The light ray refracts along the plastic-air boundary when it reaches X. Which equation is correct?

1. Asin i = \frac{\sin 41^\circ}{n}
2. Bsin i = \frac{n}{\sin 49^\circ}
3. Csin i = n \times \sin 41^\circ
4. Dsin i = n \times \sin 49^\circ

As printed in the paper