Question

D. Answer the following questions in brief.
1.
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

a) Medium 2 has higher optical density. More the optical density, lesser the speed of light through that medium. Hence Medium 1 is less optically dense than Medium 2.

b) When the incident ray is incident perpendicular to the junction seperating the two mediums, there shall be no change in the path of the light.