Q. In a Young’s double slit experimental arrangement shown here, if a mica sheet of thickness $t$ and refractive index $\mu$ is placed in front of the slit $S_{1}$, then the path difference $(S_{1}P - S_{2}P)$
A) Decreases by $(\mu - 1)t$
B) Increases by $(\mu - 1)t$
C) Does not change
D) Increases by $\mu t$
Explanation
(b) Path difference at $P\Delta = \left( S_{1}P + (\mu - 1)t \right) - S_{2}P$
$= \left( S_{1}P - S_{2}P \right) + (\mu - 1)t$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.