A flat glass slab of thickness `6 cm` and index `1.5` is placed in front of a plane mirror. An observer is standing behind the glass slab and looking at the mirror. The actual distance of the observer from the mirror is `50 cm.` The distance of his image from himself, as seen by the observer is

Options

A. `94 cm`
B. `96 cm`
C. `98 cm`
D. `100 cm`

Answer

B

Explanation

Shift`=(1-1/mu)t=(1-2/3)(6)=2 cm`
For mirror, object distance `=50-2=48 cm`.
So, mirror will make image at a distance `48 cm`
behind it. In return journey of ray of light, we will have to farther take 2 cm shift in the direction of
ray of light,
So, image distance as observed by observer
`=(50+48)-2=96 cm`