Question

In Young's experiment, monochromatic light is used to illuminate the two slits $A$ and $B$. Interference fringes are observed on a screen placed in front of the slits. Now if a thin glass plate is placed normally in the path of the beam coming from the slit

• A. The fringes will disappear
• B. The fringe width will decrease
• C. The fringe width will increase
• D. There will be no change in the fringe width but the pattern shifts

Answer 1

Answer: (D)

In the presence of thin glass plate, the fringe pattern shifts, but no change in fringe width.