Light of wavelength 520 nm in a double-slit experiment gives the relative-intensity versus angular-position graph shown in the source. Find the slit separation d in mm.

Question

G1 Physics · Accepted Answer

From the graph, use the angular spacing between adjacent maxima/minima to obtain angular fringe width Δθ≈λ/d. Substituting λ=520 nm and the indicated angular spacing gives d≈1.99×10⁻² mm.