Question

1. Relate the speed of light in the given medium with its optical density.
2. Using the information given in the table below, arrange the medium A, B and C in the ascending order of their optical density.
   

   Medium	Speed of light (m/s)
   A	2.25 × 108
   B	2 × 108
   C	2.08 × 108

Answer 1

(a) The optical density of a medium is inversely proportional to the speed of light in that medium
`n = c/v`
This means a medium with a higher speed of light has a lower optical density, and vice versa.

(b) Calculate n for each (using c = 3.00 × 10⁸ m/s):

A: `=(3 xx 10^8)/(2.25xx10^8)`

= 1.333

B: `=(3xx10^8)/(2xx10^8)`

= 1.50

C: `= (3xx10^8)/(2.08xx10^8)`

≈ 1.442

A < C < B

Medium	Speed of light (m/s)
A	2.25 × 108
B	2.08 × 108
C	2 × 108