A two-slit Young's experiment is done with monochromatic light of wavelength 6000 Å. Slits are 2 mm apart and fringes are observed on a screen placed 10 cm away from the slits. If a transparent plate of thickness 0.5 mm is placed in front of one of the slits, the interference pattern shifts by 5 mm. Then the refractive index of the transparent plate should be:
Correct answer: B. 1.2
- A. 1.1
- B. 1.2
- C. 1.3
- D. 1.5
Explanation
When a transparent plate of thickness 0.5 mm is placed in front of one of the slits, the interference pattern shifts by 5 mm. This shift occurs due to the change in optical path length caused by the plate. By calculating the change in optical path length and using the given values of slit separation, screen distance, and shift distance, the refractive index of the plate is determined to be 1.2. The correct answer is Option B. Options A, C, and D are incorrect as they do not match the calculated refractive index value based on the provided scenario.
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Light is studied through reflection, refraction, dispersion, interference, diffraction and polarization, linking ray behavior with its wave nature. Questions may involve mirrors, lenses, optical instruments, refractive index and image formation, while geometrical optics deals with rays and wave optics explains effects such as interference and diffraction.
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