Question

A laser beam entering water (refractive index = 1.33) refracts at ${12}^{\circ}$ to the normal. What was the angle of incidence?

Answer 1

Assume laser beam through Air then hits water

Refractive index of air +- 1

Use Snell's Law = n1Sinθ1 = n2Sinθ2

n1 = Refractive index of material 1

n2 = Refractive index of material 2

θ1 = Angle of Incidence

θ2 = Angle of Refraction

n1Sinθ1 = n2Sinθ2

1Sinθ1 = 1.33Sin12°

θ1 = Sin^-1(1.33Sin12°)

θ1 = 16.05°