A glass surface is coated by an oil film of uniform thickness 1.00 × 10 -4 cm. The index of refraction of the oil is 1.25 and that of the glass is 1.50. Find the wavelengths of light in the visible region (400 nm-750 nm) which are completely transmitted by the oil film under normal incidence.

A glass surface is coated by an oil film of uniform thickness 1.00 × 10^-4 cm. The index of refraction of the oil is 1.25 and that of the glass is 1.50. Find the wavelengths of light in the visible region (400 nm-750 nm) which are completely transmitted by the oil film under normal incidence.

Given, refractive index,

And thickness of the film be the

Here, the light is transmitted in normal incidence.

Therefore,

now, for n=3

now, for n=4

now, for n=5

1