A glass slab having refractive index n and thickness d is placed on the paper on table. A dot (drop) of dink is made on paper below glass slab. At how much height will the dot be found if it is observed from the upper side of slab?

Options

A. `(n-1)d/n`
B. `(n+1)d/n`
C. `((n)/(n-1))d`
D. `((n)/(n+1))d`

Answer

A, D

Explanation

Shift = real depth - virtual depth = `h_0-h_i`
`=h_0-(h_0)/(n)[because (h_i)/(h_0)=1/n therefore h_i=(h_0)/(n)]`
`=(nd-d)/(n)` (here `h_0`=d)
`therefore` Shifting in dot `= (n-1)d/n`