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10. Wave optics — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics10. Wave optics1 Mark
MCQ
Two coherent light sources $S_1$ and $S_2$ ($\lambda= 6000 Å$) are $1mm$ apart from each other. The screen is placed at a distance of $25 \,cm$ from the sources. The width of the fringes on the screen should be
  • ✓
    $0.015 \,cm$
  • B
    $0.025\, cm$
  • C
    $0.010\, cm$
  • D
    $0.030 \,cm$
✓

Answer

Correct option: A.
$0.015 \,cm$
a
(a)$\beta = \frac{{6000 \times {{10}^{ - 10}} \times 25 \times {{10}^{ - 2}}}}{{{{10}^{ - 3}}}}$

$ = 1500 × {10^{ - 9}} = 0.15 × {10^{ - 3}}m = 0.015cm.$
.

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