Question

A glass slab of thickness 12 mm is placed on a table. The lower surface of the slab has a
black spot. At what depth from the upper surface will the spot appear when viewed from above?
(Refractive index of glass = 1.5)


​

Answer 1

=8mm.

Explanation:

The real depth of the spot =12mm

We have

apparent depth

real depth

=μ

or

apparent depth

12mm

=1⋅5

or apparent depth =

1⋅5

12mm

=8mm.