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Wave Optics — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsWave Optics3 Marks
Question
In a single slit diffraction experiment, when a tiny circular obstacle is placed in the path of light from a distant source, a bright spot is seen at the centre of the shadow of the obstacle. Explain why?

State two points of difference between the interference pattern obtained in Young’s double slit experiment and the diffraction pattern due to a single slit.

✓

Answer

Explanation: Waves diffracted at the edge of circular obstacle interfere constructively at the centre of the shadow producing a bright spot.
Points of Differences:
  1. In interference, All bright fringes are of equal intensity, while in diffraction intensity of secondary maxima keeps on decreasing.
  2. Width of all fringes are equal in interference pattern but, in diffraction the width of central maximum and  the secondary maxima are different.

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