Question

(a) Define refractive index of a transparent medium. What is its unit ? Which has higher refractive index, glass or water ?

(b) A ray of light travelling in air enters obliquely into water. Does the light ray bend towards or away from the normal
(with referance to refractive index).

Answer 1

the extent of change in direction of ray of light from one medium to another is expressed as refractive index. it has no unit  .glass has higher refractive index.

b) towards the normal. when the ray of light passes from optically rarer medium to optically denser it bends toward s normal.here air is rarer medium and water is denser
 hope this helps!!

Answer 2

The of change in direction of ray of light from one medium to another is expressed as refractive index.
  No SI unit  
.Glass has higher refractive index.

  When the ray of light passes from rarer medium to  denser it bends toward s normal.here air is rarer medium and water is denser.

@The Broken Girl