Question

what are the two types of refractive indexes?

Answer 1

*refractive index through rarer medium and

*refractive index through denser medium

are the 2 types of refractive index.

Answer 2

The two types of refractive index are :
1)Absolute refractive index and
2)relative refractive index .
If medium 1 is vacuum or air ,then the refractive index of medium 2 is considered with respect to vacuum .this is called the absolute refractive index of the medium .
whereas relative refractive index ...of medium 2 with respect to medium 1 is just the ratio of speed of light in medium 1 and speed of light in medium 2.
Hope it helps u mate!!!!