Aglass plate (n = 1.60) is covered with a thin, uniform layer of oil (n = 1.29). a light beam of variable wavelength from air is incident normally on the oil surface. observation of the reflected beam shows constructive interference at 511 nm. determine the minimum non-zero thickness of the oil film.

The thickness of the oil film is 198 nm.

Explanation:

Given that,

Refractive index of glass plate = 1.60

Refractive index of oil = 1.29

Wavelength = 511 nm

We need to calculate the thickness of the oil film

Using formula of path difference

Where, n = refractive index

t = thickness

= wavelength

Put the value into the formula

Hence, The thickness of the oil film is 198 nm.

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