In a double slit experiment, when one of the slits is covered by a transparent mica sheet of refractive index 1.56

Question

In a double slit experiment, when one of the slits is covered by a transparent mica sheet of refractive index 1.56, the central fringe shifts to the position of 7th bright fringe, obtained with both slits uncovered. If the light source wavelength is 450 nm, the thickness of mica sheet is $α \times 10^{- 9}$ m. The value of $α$ is ______. [2026]

Smart Achievers · Accepted Answer

(5625)

$Given: μ = 1.56, n = 7 and λ = 450 nm = 450 \times 10^{- 9} m$

$t = thickness of mica sheet$

$t = \frac{n λ}{μ - 1} = \frac{7 \times 450 \times 10^{- 9}}{1.56 - 1} = 225 \times 25 \times 10^{- 9} m$

$α \times 10^{- 9} = 5625 \times 10^{- 9} m \Rightarrow α = 5625$

Solution

Ans.
(5625)

$Given: μ = 1.56, n = 7 and λ = 450 nm = 450 \times 10^{- 9} m$

$t = thickness of mica sheet$

$t = \frac{n λ}{μ - 1} = \frac{7 \times 450 \times 10^{- 9}}{1.56 - 1} = 225 \times 25 \times 10^{- 9} m$

$α \times 10^{- 9} = 5625 \times 10^{- 9} m \Rightarrow α = 5625$

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Solution

Ans. (5625) Given: μ=1.56, n=7 and λ=450 nm=450×10-9 m t=thickness of mica sheet t=nλμ-1=7×450×10-91.56-1=225×25×10-9 m α×10-9=5625×10-9 m⇒α=5625

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Ans.
(5625)

$Given: μ = 1.56, n = 7 and λ = 450 nm = 450 \times 10^{- 9} m$

$t = thickness of mica sheet$

$t = \frac{n λ}{μ - 1} = \frac{7 \times 450 \times 10^{- 9}}{1.56 - 1} = 225 \times 25 \times 10^{- 9} m$

$α \times 10^{- 9} = 5625 \times 10^{- 9} m \Rightarrow α = 5625$