Question

The ratio of the speed of light in a medium to the speed of light in a vacuum

is called its:
A. angle of incidence
B. Snell's Law
C. angle of refraction
D. refractive index

Answer 1

You're going for "refractive index", but you've got the ratio flipped over.

Answer 2

Answer:D.Refractive Indez

Step-by-step explanation:

It is usually expressed the other way: the ratio of the speed of light in a vacuum to the speed of light in a medium. In that case, it is called the "index of refraction".