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In Young’s double slit experiment, slit separation is 0.1 cm and screen distance is 50 cm. One slit is covered with a transparent sheet of refractive index 1.5 causing a shift of 0.2 cm in central fringe. Thickness of the sheet is

In Young’s double slit experiment, slit separation is 0.1 cm and screen distance is 50 cm. One slit is covered with a transparent sheet of refractive index 1.5 causing a shift of 0.2 cm in central fringe. Thickness of the sheet is: Options:
  1. $(8\times10^{-4})$ cm
  2. $(6\times10^{-3})$ cm
  3. $(5.6\times10^{-4})$ cm
  4. $(5\times10^{-3})$ cm

Solution:

Fringe shift formula: $[ x = \frac{(\mu - 1)tD}{d} ]$ $[ t = \frac{xd}{D(\mu - 1)} ]$ Substituting: $[ t = 8\times10^{-4}\ \text{cm} ]$ ✅ Correct Answer: (1)
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