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_(r)=(mu_(v)+mu_(R))/2=(1.50+1.60)/2=1.55`
(b) `omega=(mu_(v)-mu_(R))/(mu_(r)-1)=(1.60-1.50)/(1.55-1)=0.18`.