In a young's double slit experiment, green light is incident on the two slits. The interference pattern is observed on a screen. Which of the following changes would cause the observed fringes to be more closely spaced?

Options

A. Reducing the separation between the slits
B. Using blue light instead of green light
C. used red light instead of green light
D. Moving the light source futher away from the slits.

Answer

B

Explanation

Fringes to be more closed when fringe width becoems reduced fringe width `beta=(lamdaD)/(d)`
As `lamda` decrease `beta` also decreases `(lamda_("blue")ltlamda_("green"))`