A certain material has refractive indices 1.56, 1.60 and 1.68 for red, yellow and violet light respectively. A Calculate the dispersive power. B Find the angular dispersion produced by a thin prism of angle 6 made of this material.
Given that
Refractive index of red light = μr = 1.56
Refractive index of yellow light = μy = 1.60
Refractive index of violet light = μv = 1.68
Refracting angle of prism=A= 6.0°
A Dispersive power = ω = 
= 
[substituting values]
= 
B Angular dispersion = δ = 
= 
= 
= 
Thus, the angular dispersion produced by the thin prism is 0.72°
1