PHYSICS · Single correct · A Level · Physics · Waves · Waves
Problem
In Young's double-slit experiment, the slits are illuminated by monochromatic light. The entire setup is immersed in pure water. Which of the following acts cannot restore the original fringe width?
(1) Bringing the slits close together.
(2) Moving the screen away from the slit plane.
(3) Replacing the incident light by that of longer wavelength.
(4) Introducing a thin transparent slab in front of one of the slits.