The refractive index of a material changes by 0.014 as the color of the light changes from red to violet. A rectangular slab of height 2.00 cm made of this material is placed on a newspaper. When viewed normally in yellow light, the letters appear 1.32 cm below the top surface of the slab. Calculate the dispersive power of the material.
Given that,
refractive index of a material changes= = 0.014
μv and μr be the refractive indices of violet and red colors
Actual depth = Thickness of slab = t = 2cm
Apparent depth = t’ = 1.32cm
Therefore,
μy =
= =
Dispersive power = ω =
= =
Thus, the dispersive power of the material is 0.027