The refractive index of a material changes by 0.014 as the colour 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.

Answer

B

Explanation

Given that `: mu-mu_r=0.014`
Again` mu_r=(Real depth)/(Apparent depth)`
`=2.00/1.32=1.515`
so, dispersive power `(mu_v-mu_r)/(mu_y-1)`
`=0.014/(1.515-1)`
`=0.014/0.515=0.027`