A glass sphere with `10 cm` radius has a `5 cm` radius spherical hole at its centre. A narraow beam of parallel light is directed into the sphere. Where, if anywhere, will the sphere produce an image? The index of refraction of the glass is `1.50.`

Answer

A, C, D

Explanation

Apply `mu_2/v-mu_1/u=(mu_2-mu_1)/R` four times,
We have `1.5/v_1-1.0/oo=(1.5-1.0)/(+10)`
`:. v_1=+30 cm`
`1.0/v_2-1.5/(+2.5)=(1.0-1.5)/(-5.0)`
`v_2=-25 cm`
`1.5/v_3-1.0/(-3.5)=(1.5-1.0)/(-5.0)`
`v_3=-11.67 cm`
`1.0/v_4-1.5/(-16.67)=(1.0-1.5)/(-10)`
`rArr v_4=-25 cm`
`:.` Final image is at `25 cm` to the left of P.`