Question

There is a black spot on a table. A glass slab of thickness 6 cm is placed on the table over the spot. Refractive index of glass is 3/2. At what depth from the upper surface will the spot appear when viewed from above?

Answer 1

Real depth of spot = 6 cm

Refractive index of glass, n = $\frac{3}{2}$

n = $\frac{Realdepth}{Apparentdepth}$

$\frac{3}{2}$ = $\frac{6}{Apparentdepth}$

Apparent depth = 4 cm