Q. In Young’s double slit experiment, if $L$ is the distance between the slits and the screen upon which interference pattern is observed, $x$ is the average distance between the adjacent fringes and $d$ being the slit separation. The wavelength of light is given by
A) $\frac{xd}{L}$
B) $\frac{xL}{d}$
C) $\frac{Ld}{x}$
D) $\frac{1}{Ldx}$
Explanation
(a) We know that fringe width $\beta = \frac{D\lambda}{d}$
$\therefore x = \frac{L\lambda}{d} \Rightarrow \lambda = \frac{xd}{L}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.