Question

The index of refraction for red light in a certain liquid is 1.303; the index of refraction for violet light in the same liquid is 1.326. part a find the dispersion θv−θr for red and violet light when both are incident on the flat surface of the liquid at an angle of 45.00 ∘ to the normal.

Answer 1

Snell's law states: n1/n2 = Sin Ф2/Sin Ф1

But n2/n1 = 1.303 and 1.326 for red light and violet light respectively (for this case) and Ф1 = 45

Therefore,
Фr = Sin ^-1{1/1.303 *Sin 45} = 32.87°
Фv = Sin ^-1 {1/1.326* Sin 45} = 32.23°

Then,
Dispersion, Фv - Фr = 32.23 - 32.87 = -0.64°