Question

 Describe, quoting the necessary formula how you would determine the wavelength of monochromatic light by observation of Young's fringes.

Answer 1

Answer

Schematic diagram to better understand

Using above concepets and diagram notation So wavelength is given by

Path difference $n\lambda$ =$\frac{xd}{D}$

So wavelength is given

$\lambda=\frac{xd}{nD}$