Double-slit fringe spacing
In a double-slit experiment, which change increases the spacing between bright fringes on the screen?
Answer C: explanation for every choice
A
A larger slit separation d decreases the spacing.
B
A smaller distance L to the screen decreases the spacing.
C
Correct. Fringe spacing Δy = λL/d, so a longer wavelength spreads the fringes.
D
Higher frequency means shorter wavelength, which decreases the spacing.
TakeawayFringe spacing Δy = λL/d.
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Reviewed 2026-11-05 by a medical student. Spot an error? Report it with question ID cp94.