Physics for IGCSE & O level - Rays And Waves (Section 11 - No. 46)
What formula is used to calculate the refractive index of a material?
speed of light / speed of light in the medium
speed of light * speed of light in the medium
speed of light + speed of light in the medium
speed of light - speed of light in the medium
Explication
The refractive index is calculated by dividing the speed of light in a vacuum by the speed of light in the medium.