Consider layers of three media of different index of refraction. The thickness of layers is the same, say L. Medium A has index of refraction 1.3; medium B has index of refraction 1.4 and medium C has index of refraction 1.35. Light enters these layers normally from the air. Rank these media in accordance the time it takes for light to travel through these layers, greatest first.

Medium A - > medium C - > medium B

Explanation:

Refraction is defined a s the change in the direction of light rays as it moves from one medium to another. The speed of the light in this media depends on the nature and the refractive indices of the media.

Light has the tendency to travel faster through a medium with low refractive index rather than high refractive index.

Comparing this medias based on the above conclusion

Medium A has index of refraction 1.3; medium

B has index of refraction 1.4 and medium

C has index of refraction 1.35

The light will travel faster in medium A since it have the lowest refractive index followed by medium C then medium B.

Ranking of the media in accordance the time it takes for light to travel through these layers are as shown

Medium A - > medium C - > medium B