Physics
Physics
Problem
Identify what happens to the angular width of the principal (central) maximum when the number of identical, equally spaced slits in an interference experiment is increased while the slit separation remains constant.Intuitive explanation
The central maximum's angular width is determined by the first minimum, which occurs when path differences between the outermost slits equal one wavelength. As you add more slits with fixed spacing, the total span of the slit array grows, creating larger path differences across the pattern—so the first minimum appears at a smaller angle. This means the central peak becomes narrower, more sharply defined, and brighter as increases.
Intuitive explanation
The central maximum's angular width is determined by the first minimum, which occurs when path differences between the outermost slits equal one wavelength. As you add more slits with fixed spacing, the total span of the slit array grows, creating larger path differences across the pattern—so the first minimum appears at a smaller angle. This means the central peak becomes narrower, more sharply defined, and brighter as increases.