The minimum deviations suffered by red, yellow and violet beams passing through and equilateral transparent prism are 38.4°, 38.7° and 39.2° respectively. Calculate the dispersive power of the medium.

Question

Philoid · Accepted Answer

Given that

Minimum Deviations by Red = δ_r = 38.4⁰

Minimum Deviations by Yellow = δ_y = 38.7⁰

Minimum Deviations by Violet = δ_v = 39.2⁰

If A is the angle of prism having refractive index μ, then the angle of minimum deviation is given by

Therefore,

Dispersive power =

=

So, the dispersive power of the medium is 0.0204