Two wavelengths 600 nm and 450 nm illuminate the same Young's double-slit experiment. The ratio D ÷ d is 2000. What is the distance from the central maximum to the first common non-central bright fringe?
Options

Question

Two wavelengths 600 nm and 450 nm illuminate the same Young's double-slit experiment. The ratio D ÷ d is 2000. What is the distance from the central maximum to the first common non-central bright fringe?

Options

G1 Physics · Accepted Answer

The first common bright fringe satisfies 3×600 nm = 4×450 nm = 1800 nm. Therefore, y = (mλ)D ÷ d = 1800×10⁻⁹×2000 = 3.6×10⁻³ m = 3.6 mm. Correct option: C.