00:01
The speed of light, c in vacuum, and the speed of light in some medium, whose refractive index is say n, are related by the relation n is equal to c by v.
00:22
Now, what is c? c is f times lambda, where lambda is the wavelength of that light in vacuum.
00:37
We can be written in the same way.
00:41
It's just the wavelength which will be changed as the medium will be.
00:50
Therefore, substituting both in this relation of reflective index, f lambda vacuum while f lambda, medium, medium.
01:09
Therefore, ff will cancel out and lambda vacuum, which is a constant quantity and medium, which can vary it.
01:26
Therefore, n is equal to 1 by lambda medium...