Statement 1: In the shown YDSE, the central bright fringe is initially at O. If the region between the slit plane and the screen is completely filled with a liquid, the central bright fringe shifts upward. Statement 2: If the path difference at O changes, the y-coordinate of the central bright fringe changes.

Question

G1 Physics · Accepted Answer

If the same liquid fills the complete region between both slits and the screen, both optical paths are multiplied by the same refractive index, so the zero-path-difference point remains at O; Statement 1 is false. In general, if the path difference at O changes asymmetrically, the central maximum shifts, so Statement 2 is true. Option D.