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MHT CET · Physics · Wave Optics

A double slit experiment is immersed in water of refractive index 1.33. The slit separation is \(1 \mathrm{~mm}\), distance between slit and screen is \(1.33 \mathrm{~m}\) The slits are illuminated by a light of wavelength \(6300 Å\). The fringe width is

  1. A \(4.9 \times 10^{-4} \mathrm{~m}\)
  2. B \(5.8 \times 10^{-4} \mathrm{~m}\)
  3. C \(6.3 \times 10^{-4} \mathrm{~m}\)
  4. D \(8.6 \times 10^{-4} \mathrm{~m}\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(6.3 \times 10^{-4} \mathrm{~m}\)

Step-by-step Solution

Detailed explanation

\(
\begin{aligned}
& \lambda_{\text {liquid }}=\frac{\lambda_{\text {sir }}}{\mu} \\
& \lambda_{\text {liquid }}=\frac{6300 \times 10^{-10}}{1.33}
\end{aligned}
\)
Fringe width,
\(
\mathrm{W}=\frac{\lambda_{\text {liquid }} \times \mathrm{D}}{\mathrm{d}}=\frac{6300 \times 10^{-10} \times 1.33}{1.33 \times 0.001}=6.3 \times 10^{-4} \mathrm{~m}
\)