Question

g A thin uniform film of oil that can be varied in thickness covers a sheet of glass of refractive index 1.52. The refractive index of the oil is 1.64. Light of wavelength 555 nm is shone from air at normal incidence on the film. Starting with no oil on the glass, you gradually increase the thickness of the oil film until the first interference maximum in the reflected light occurs. What is the thickness of the oil film at that instant

Answer 1

Answer:

The right solution is "84.09 nm".

Explanation:

The given values are:

Refractive index of glass,

= 1.52

Refractive index of oil (n),

= 1.64

Wavelength (λ),

= 555 nm

Now,

The thickness of the film (t) will be:

= $\frac{\lambda}{4n}$

= $\frac{555}{4\times 1.65}$

= $\frac{555}{6.6}$

= $84.09 \ nm$