A plastic hemisphere has a radius of curvature of `8 cm` and an index of refraction of `1.6` . On the axis halfway between the plane surface and the spherical one `( 4 cm `from each`)` is a small object `O`.
The distance between the two images when viewed along the axis from the two sides of the hemisphere is approximately

Options

A. `1.0 cm`
B. `1.5 cm`
C. `3.75 cm`
D. `2.5 cm`

Answer

D

Explanation

Distance of image from the plane surface is `:`
`x_(1)=(4)/(1.6)=2.5cm``(d_(app)=(d_(actucal))/(mu))` for the curved side `(1.6)/(4)+(1)/(x_(2))=(1-1.6)/(8)`
`:. x_(2)~~-3.0 cm`
The minus sign means the image is on the object side
`:. I_(1)I_(2)=(8-2.5-3.0)cm =2.5 cm`