Find the dispersion produced by a thin prism of 18° having refractive index for red light = 1.56 and for violet light = 1.68.
Answer & explanation
Correct answer: option 3
The dispersion produced by a thin prism is $\theta = (\mu_V - \mu_R)A = (1.68 - 1.56)18^o = 2.16^o$