Answer:
Angle of refraction.
Explanation:
Refractive index is given as the ratio of the angle of incidence to the angle of refraction.
If angle of incidence is i and the refractive index of the incident medium is n₁ , and if angle of refraction is r and refractive index of the refracting medium is n₂,
according to Snell's law, n₁ sin i = n₂ sin r,
relative refractive index = sin i / sin r
