What is refractive index ?
A
it is defined as the ratio of speed of light in the medium to the speed of light in vacuum.
B
it is defined as the product of speed of light in medium and in vacuum.
C
it is defined as the ratio of speed of light in vacuum to the speed of light in the medium .
D
None of above
Correct Answer: it is defined as the ratio of speed of light in vacuum to the speed of light in the medium .