In a Young's double slit experiment, the separation between the two slits is d and distance of the screen from the slits is 1000 d. If the first…

Obtaining relation between d & \(\displaystyle \lambda\) \(\displaystyle \mathrm{D}=1000 \mathrm{~d}\) \[x_{1 \mathrm{d}}=\mathrm{d} \] Position of \(\displaystyle 1^{\text {st }}\) minima. \[\begin{aligned} & x_{1 \mathrm{d}}=\frac{3}{2} \cdot \frac{\lambda \mathrm{D}}{\mathrm{d}} \\ & \mathrm{d}=\frac{3}{2} \cdot \frac{\lambda \times 1000 \mathrm{d}}{\mathrm{d}} \\ & \therefore \quad \mathrm{d}=1500 \lambda \end{aligned} \]