Question

A glass block of thickness 12 cm is placed on a mark placed on a plain paper. The mark is viewed normally through the glass. Calculate the apparent depth of the mark and hence the vertical displacement. (refractive index of glass is 1.5)

Answer 1

ang =    real depth     
          apparent depth
apparent depth = real depth = (12 × 2) = 8 cm
                                  ang                     3
vertical displacement= 12 - 8 = 4 cm