Question Detail
Question
In Young's interference experiment, if the separation between the slits is halved and the distance between slits and the screen is doubled then the fringe width is:
Correct Answer
Option A is the correct answer.
Detailed Explanation
Fringe width β = λL/d. If d is halved (d' = d/2) and L is doubled (L' = 2L), then β' = λ(2L)/(d/2) = 4λL/d = 4β. The fringe width is quadrupled.
Hint
Fringe width β is proportional to L and inversely proportional to d: β = λL/d.