Question

Why is refractive index in a transparent medium greater than one ?(a) Because the speed of light in vaccum is always less than speed in a transparent medium(b) Because the speed of light in vaccum is always greater than speed in a transparent medium(c) Frequency of wave changes when it crosses medium(d) None of these

Answer 1

speed of sound in vaccum is maximum.

when light enters a medium then light travels in such a way so as to travel a minimum possible distance and thus it bends acc. to the conditions resultin refraction and due to this its velocity decreases