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PhysicsJEE Main 21 Jan 2026, Shift 1·Q11·MCQ·Easy–moderate

Wave Optics · Interference

In a double slit experiment the distance between the slits is 0.1 cm and the screen is placed at 50 cm from the slits plane. When one slit is covered with a transparent sheet having thickness tt and refractive index n (=1.5)n\,(=1.5), the central fringe shifts by 0.2 cm. The value of tt is cm.
  1. (1)8×10−48\times10^{-4}
  2. (2)6.0×10−36.0\times10^{-3}
  3. (3)5.6×10−45.6\times10^{-4}
  4. (4)5.0×10−35.0\times10^{-3}

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