Question

Light propagates faster through a Medium A than through another Medium B.
(a) Which of the two media has a higher optical density?
(b) State the condition under which no 'change in the direction of propagation' of a light ray would take place when it passes from Medium A to
Medium B.​

Answer 1

Optical Density

Explanation:

a.The optical density of medium B is higher than that of medium A.  

More the optical density a medium has, lesser the speed of light through it. Thus optically density of medium A is less than Medium B.

b. When the light ray is incident in a direction perpendicular to the surface that isolating the two mediums, then there would be no change in the path of the light.