Q. The separation between successive fringes in a double slit arrangement is$x$. If the whole arrangement is dipped under water, what will be the new fringe separation? $\lbrack The\ wavelength\ of\ light\ being\ used\ in\ 5000\ \mathring{\mathrm{A}}\rbrack$
A) $1.5\ x$
B) $x$
C) $0.75\ x$
D) $2\ x$
Explanation
(c) When the arrangement is dipped in water,
$\beta^{'} = \frac{\beta}{\mu} = \frac{x}{4/3} = \frac{3}{4}x = 0.75x$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.