Question

The refractive indices of water for red and violet colours are 1.325 and 1.334 respectively.
Find the difference between the velocities of rays for these two colours in water. (c = 3 × 10⁸ m/s)

Answer 1

= [log (27) − log (1.325) − log (1.334)] × 10⁵

= [1.4314 − 0.1222 − 0.1252] × 10⁵

= [antilog (1.184)] × 10⁵

= 15.28 × 105 = 1.528 × 10⁶ m/s.

The difference between the velocities of rays for red and violet colours in water is
1.528 × 10⁶ m/s.