Question

In Young's two-slit experiment, the first dark fringe above the central bright fringe occurs at an angle of 0.54 degree. What is the ratio of the slit separation, d to the wavelength of the light, lambda? Express your answer using two significant figures. d/lambda =

Answer 1

We know

   $d \sin \theta=(m-\frac{1}{2})\lambda$

Given $\theta=0.54^o$

   $m=1$

$\frac{d}{\lambda}=\frac{(1-\frac{1}{2})}{sin 0.54}$

${\color{Red} \frac{d}{\lambda}=53.05} (ans)$