In a Young's double slit experiment, the two parallel slits are 1 mm apart and a screen is placed 1 m away from the slits. When the light of wavelength 600 nm is used, the fringe width is
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \( 0.6\,\mathrm{mm} \)
In Young's double slit experiment the fringe width is the distance between two successive bright (or dark) fringes.
\( \displaystyle \beta = \frac{\lambda D}{d} \)
\( \lambda = 600\,\mathrm{nm} = 6\times10^{-7}\,\mathrm{m} \)
\( D = 1\,\mathrm{m} \)
\( d = 1\,\mathrm{mm} = 10^{-3}\,\mathrm{m} \)
\( \displaystyle \beta = \frac{6\times10^{-7} \times 1}{10^{-3}} = 6\times10^{-4}\,\mathrm{m} = 0.6\,\mathrm{mm} \)
Note: A similar question was also asked in CUET (UG) 2023 on 05-06-2023 (Slot 1).