A light source emits λ₁=400 nm and λ₂=600 nm in a Young's double-slit experiment. If fringe widths are β₁ and β₂ and the numbers of fringes within the same distance y on one side are m₁ and m₂, choose the correct statement(s).
Select all that apply

Question

A light source emits λ₁=400 nm and λ₂=600 nm in a Young's double-slit experiment. If fringe widths are β₁ and β₂ and the numbers of fringes within the same distance y on one side are m₁ and m₂, choose the correct statement(s).

Select all that apply

G1 Physics · Accepted Answer

Fringe width β=λD/d, so β₂/β₁=600/400=3/2 and β₂>β₁. For a fixed distance, the shorter wavelength produces more fringes, so m₁>m₂. Also 3λ₂=1800 nm and the 5th minimum of λ₁ has path difference 9λ₁/2=1800 nm, so those overlap. Correct: A,B,C.