A metal plate is lying at the bottom of a tank full of a transparent liquid. Height of tank is 100 cm but the plated appears to be at 45 cm above bottom. The refractive index of liquid is:

1.00 1.53 1.81 1.32

1.81

Real depth of plate, H = 100 cm Apparent depth of plate, h = 100 – 45 = 55 cm ∴ Refractive index of fluid = $\frac{H}{h} = \frac{100}{55}$ = 1.81