Answer:
in a vacuum to the speed of light in the material
Explanation:
The index of refraction, also known as the refractive index, is the ratio of the speed of light in a vacuum to the speed of light in the material.
When light rays travel travels from one medium to another, it bends as a result of a change in the speed of traveling from the first medium to the second medium.
The refractive index (n) of a material is calculated by:
sin i/sin r
Where i = the incidence angle of the traveling ray in the vacuum and r = angle of refraction.
The refractive index (n) is also given as:
c/v
Where c = velocity of light in the vacuum and v = velocity of light in the material.
