Assertion (A): In Young’s double-slit experiment, covering one slit with a thin transparent sheet causes the entire fringe pattern to shift without changing the fringe width.
Reason (R): The sheet introduces an additional constant phase difference between the two waves reaching the screen, but their wavelength remains the same.
Choose the correct option:
(a) A is true, R is false.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) Both A and R are true, and R is the correct explanation of A.
(d) A is false, R is true.