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MHT CET 2025 (22 Apr, Shift 1) · YDSE: Fringe Width & Fringe Positions

YDSE: Fringe Width & Fringe Positions question from MHT CET 2025 (22 Apr, Shift 1)

Q18MHT CET 2025 · 22 APR · SHIFT 1Medium

YDSE: Fringe Width & Fringe Positions

In a Young's double slit experiment wavelength of light used is 6000 A˚6000\ \text{Å}. The first order maxima and tenth order maxima fall at 14.50 mm and 16.75 mm from the particular reference point in the interference pattern respectively. If the wavelength is changed to 5500 A˚5500\ \text{\AA} then the position of zero order and tenth order maxima are respectively

[The other arrangements remaining same]

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Answer: (a)

  1. From 1st to 10th maxima: 9β=16.75−14.50=2.259\beta = 16.75 - 14.50 = 2.25 mm, so β=0.25\beta = 0.25 mm
  2. Zero order lies at 14.50−0.25=14.2514.50 - 0.25 = 14.25 mm; it does not move when λ\lambda changes.
  3. New β′=0.25×55006000≈0.229\beta' = 0.25 \times \frac{5500}{6000} \approx 0.229 mm; 10th maximum at 14.25+10(0.229)≈16.5414.25 + 10(0.229) \approx 16.54 mm
  4. So the answer is (a) 14.2514.25 mm, 16.5516.55 mm.
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