Q.From the given data set, determine angular dispersion by the prism and dispersive power of its material for extreme colours. nR = 1.62, nV = 1.66, δR = 3.1°

[!TLDR] With A=delta_R/(n_R-1)=5 degrees, delta_V=A(n_V-1)=3.3 degrees, giving angular dispersion 0.2 degrees and dispersive powe …

For a thin prism, delta=A(n-1) for each colour, with the SAME prism angle A for both. From the given delta_R=3.1 degrees and n_R=1.62: A = delta_R/(n_R-1) = 3.1/0.62 = 5.0 degrees. Using this same A for violet: delta_V = A(n_V-1) = 5.0 x 0.66 = 3.3 degrees. Angular dispersion: delta_VR = delta_V - delta_R = 3.3-3.1 = 0.2 degrees. Mean deviation (using yellow as the mean, n_Y=(n_R+n_V)/2=1.64): delta_Y = A(n_Y-1) = 5.0 x 0.64 = 3.2 degrees (equi …

Use the given delta_R and n_R to find the prism's own angle A (same for both colours), apply it to find delta_V from n_V, subtract for angular dispers …

Trying to compute dispersive power without first finding the shared prism angle A, or incorrectly assuming delta_R and delta_V come f …