Solution

Question\n\nYoung's experiment is performed with light from excited helium atoms $\lambda = 502\,\mathrm{nm}$. Fringes are measured carefully on a screen $1.20\,\mathrm{m}$ away from the double slit, and the center of the $20$th fringe (not counting the central bright fringe) is found to be $10.6\,\mathrm{mm}$ from the center of the central bright fringe. What is the separation of the two slits?\n\nContent coming soon. Write the full solution here, or use the part files (p-i.mdx, p-ii.mdx, …) for each part.