Question

In a Young's double slit experiment, the slits are separated by $0.3mm$ and the screen is $1.5m$ away from the plane of slits. Distance between fourth bright fringes on both sides of central bright is $2.4cm$. The frequency of light used is ______ $\times 10^{14}Hz$

Answer 1

Answer: 5

$8\beta =2.4cm$
$\frac{8\lambda \Delta }{d}=2.4cm$
$\frac{8\times 1.5\times c}{0.3\times 10^{-3}\times f}=2.4\times 10^{-2}$
$f=5\times 10^{14}Hz$