Question

If the refractive index of a certain material with respect to air is 1.5, what is the refractive index of air with respect to that material?

Answer 1

As the refractive index of the given material with respect to air is 1.5, the refractive index of air with respect to the material is

\(\frac{1}{1.5}=\frac{1}{3/2}=\frac{2}{3}\) = 0.6667 (approximately)