In a Young's double slit experiment the wavelength of light is 500 nm, the separation between the slits is 2 mm and the distance between the slits and the screen is 1.8 m. The width of bright fringes is
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 0.45 mm
In Young’s double-slit experiment the fringe width is
\( \displaystyle \beta = \frac{\lambda D}{d} \)
\( \displaystyle \beta = \frac{500\times10^{-9} \times 1.8}{2\times10^{-3}} \)
\( \displaystyle \beta = 4.5\times10^{-4}\,\mathrm{m} = 0.45\,\mathrm{mm} \)