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

Question

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

G1 Physics · Accepted Answer

β=λD/d. To make fringes closer, β must decrease. Blue light has a smaller wavelength than green, so replacing green by blue decreases the spacing. Option B.