A small pin fixed on a table top is viewed from above from a distance of `50 cm`. By what distance would the pin appear to be raised, if it be viewed from the same point through a `15 cm`. Thick glass slab held parallel to the table ? `mu` of glass `1.5` Does the answer depend on location of the slab ?

Explanation

d=normal shift=t`-t/u=(1-1/mu)`
`=15(1-1/1.5)=15(1-2/3)`
`=15xx1/3=5 cm`
i.e., the pin appears raised by 5 cm.
No, the answer does not depend upon the location of the slab for small angle of incidence.