Two slits are made one millimetre apart and the screen is placed one metre away. When blue –green light of wavelength 500 nm is used, the fringe separation is

Q: Two slits are made one millimetre apart and the screen is placed one metre away. When blue –green light of wavelength 500 nm is used, the fringe separation is

Sol: Fringe separation, $\large \beta = \frac{\lambda D}{d}$

Given, D = 1 m , λ = 500 nm 5 × 10-7 m and d = 1 mm 1 × 10-3 m

∴ Fringe separation, $\large \beta = \frac{5 \times 10^{-7} \times 1}{1 \times 10^{-3}}$

= 5 × 10-4 m = 0.5 mm.