WAEC Physics 2011 Paper

Concept:The absolute refractive index compares the speed of light in vacuum with its speed in a given medium.Explanation:The absolute refractive index of a medium is defined as the ratio of the speed of light in vacuum to the speed of light in that medium.Here, the speed of light in vacuum is $C$ and the speed in the medium is $V$.So, refractive index $n$ is given by:$$n = \frac{C}{V}$$This matches option B.Thus, the correct choice is $\frac{C}{V}$.Answer:$$\frac{C}{V}$$ Option B.