Refractive index of glass for red and violet colours are 1.50 and 1.60, repectively. Find:
a. The refractive index for yellow colour, approximately
b. Dispersive power of the medium.

Explanation

(a) `mu_(Y) = (mu_(Y) + mu_(R))/(2) = (1.50+ 1.60)/(2) = 1.55`
(b) `omega = (mu_(Y) + mu_(R))/(mu_(y) - 1) = (1.60+ 1.50)/(1.55 - 1) = 0.18`