Sun October 23, 2011 By: Aman Anand

why is the speed of light more in a substance having low refractive index?

Expert Reply
Sun October 23, 2011
speed of light depends upon the refractive index of the medium.
mediums having different refractive index have different number of particles and when light ray from vaccuum enters a medium light interacts with these particles and thus speed of light decreases.
but if light enters into a medium of lower refractive index from a higher refractive index it faces less number of particles into medium of lower refractive index and thus its speed increases.
Ask the Expert