Double-slit diffraction — UPSC Physics Optional CSE 2024 Paper I

The intensity at the central maximum observed on a screen in a double-slit experiment is 2 \times 10^{-3}\text{ W/m}^2. If the path difference between interfering waves reaching a point on the screen is \frac{\lambda}{6}, where \lambda is the wavelength of the light used in the experiment, determine the intensity at that point.