Question

A Young's interference experiment is performed with blue-green laser light. The separation between the slits is 0.500 mm, and the screen is located 3.14 m from the slits. The first bright fringe is located 3.24 mm from the center of the interference pattern. What is the wavelength of the laser light?

Answer 1

Answer:

Wavelength of laser light will be $5.15\times 10^{-7}m$

Explanation:

We have given distance between the slits d = 0.5 mm = $0.5\times 10^{-3}m$

Distance between screen and slits D = 3.14 m

Distance of bright fringe from center $y=3.24mm=3.24\times 10^{-3}m$

It is known that $sin\Theta =\frac{y}{D}=\frac{3.24\times 10^{-3}}{3.14}=1.031\times 10^{-3}m$

It is also know that $m\lambda =dsin\Theta$, here m = 1 for first bight fringe.

$1\times \lambda =0.5\times 10^{-3}\times 1.031\times 10^{-3}$

$\lambda =5.15\times 10^{-7}m$

So wavelength of laser light will be $5.15\times 10^{-7}m$