In Young's double slit experiment, the slits are separated by 0.6 mm and screen is placed at a distance of 1.2 m from slit. It is observed that the tenth bright fringe is at a distance of 8.85 mm from the third dark fringe on the same side. The wavelength of light used is

Step-by-step solution

For n ^ th bright fringe, y _ n = n D d y ₁₀= 10 1.2 0.6 10⁻³ = (20 10^3 ) ...(i) For n ^ th dark fringe, y_n^ = (2 n-1) D 2 d y₃^ = 5 1.2 2 (0.6 10⁻³ ) = (5 10^3 ) ...(ii) Given, aligned & y₁₀-y₃^ =8.85 10⁻³ & (20 10^3 ) - (5 10^3 ) =8.85 10⁻³ aligned ...[From(i) and (ii)] aligned & = 8.85 10⁻³ 15 10^3 =5.9 10⁻⁷ ~m & =5900 Å aligned