Question

In Which Medium Velocity Of Light Is Maximum

Answer 1

Light travels at approximately 300,000 kilometers per second in a vacuum, which has a refractive index of 1.0, but it slows down to 225,000 kilometers per second in water (refractive index = 1.3) and 200,000 kilometers per second in glass (refractive index of 1.5). Speed of light is the lowest in diamonds.