A light ray transfers from more to less dense medium at certain condition , if we repeat this experiment by increasing the angle
of incidence in more dense medium to double its value in the 1st condition so the value of the relative refractive index between the 2 media is increased to double
decreased to half
still constant
there is no relative refractive index between more and less dense medium
The relative refractive index ₁n₂ between the two medium can be as follows;
Therefore, given that the speed of light in medium 1 is constant and the speed of light on medium 2 is also constant, the relative refractive index ₁n₂ = c₁/c₂ is always constant.