A hair is placed at one edge between two flat glass plates.When this arrangement is illuminated with violet light of wavelength (λ = 408 nm),a total of 109 dark bands are counted starting at the point of contact between the plates.How thick is the hair? (1 nm = 10−⁹ m)

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The correct answer is A.The thickness of the hair can be calculated using the formula:$$t = \frac{mλ}{2n}$$where:* t is the thickness of the hair* m is the number of dark bands* λ is the wavelength of light* n is the refractive index of the glassIn this case, m = 109, λ = 408 nm, and n = 1.52. Plugging these values into the formula, we get:$$t = \frac{109 × 408 nm}{2 × 1.52} = 2.2 × 10^{-5} m$$

A Hair Is Placed at One Edge Between Two Flat