Question

what is the index of refraction in quartz if light travels at 2.0567 x 108m/s when in quartz?

Answer 1

Index of refraction of a substance =

(speed of light in vacuum) / (speed of light in the substance)

Index in quartz = (2.9979 x 10⁸ m/s) / (2.0567 x 10⁸ m/s)

Index =  1.4576 (no units)