AIIMS 2018 Physics Interference MCQ Question

For dark fringes in a double-slit interference pattern, the position $x$ of the dark fringes is given by the formula $x = \frac{(2n−1) \lambda D}{2d}$, where $n$ is the order of the fringe, $\lambda$ is the wavelength of light, $D$ is the distance from the slits to the screen, and $d$ is the distance between the slits. This formula arises from the condition for destructive interference, where the path difference must equal an odd multiple of half wavelengths.

Option B incorrectly rearranges the formula, while options C and D provide numerical calculations that do not directly relate to the derivation of the dark fringe position. Understanding the underlying principles of interference is crucial for correctly applying these formulas.