Question

Refraction index of diamond is 2.42. Explain the statement

Answer 1

Hey mate here is ur ans

this statement Means that the speed of light in vacuum is 2.42 times than that of the speed in diamond
(as absolute refractive index of a medium =speed of light in air = speed of light in that medium)

hope it helps you

Answer 2

 refractive index of diamond is 2.42, it means light is travelling from rarer to denser medium, and speed of light in air(vacuum) is 2.42 times the speed of light indiamond.