Question

Light with a wavelength of λ = 689 nm. is incident on a single slit of width w = 3.75 micrometers. A screen is located L = 0.65 m behind the slit and an interference pattern has formed on it. What is the distance between the central bright spot and the first dark fringe, D, in meters?

Answer 1

Answer:

119.42 x 10⁻³ m

Explanation:

The distance of first dark fringe from central bright spot will be equal to the width of fringe .

Fringe width = λL /w

where λ is wavelength of light, w is slit width , L is distance of screen .

So required distance

= $\frac{689\times10^{-9}\times0.65}{3.75\times10^{-6}}$

= 119.42 x 10⁻³ m