Complete Question
You are performing a double slit experiment very similar to the one from DL by shining a laser on two nattow slits spaced [tex]7.5 * 10^{-3}[/tex] meters apart. However, by placing a piece of crystal in one of the slits, you are able to make it so that the rays of light that travel through the two slits are Ï out of phase with each other (that is to say, Ao,- ). If you observe that on a screen placed 4 meters from the two slits that the distance between the bright spot closest to center of the pattern is 1.5 cm, what is the wavelength of the laser?
Answer:
The wavelength is [tex]\lambda = 56250 nm[/tex]
Explanation:
From the question we are told that
The distance of slit separation is [tex]d = 7.5 *10^{-3} \ m[/tex]
The distance of the screen is [tex]D = 4 \ m[/tex]
The distance between the bright spot closest to the center of the interference is [tex]k = 1.5 \ cm = 0.015 \ m[/tex]
Generally the width of the central maximum fringe produced is mathematically represented as
[tex]y = 2 * k = \frac{ D * \lambda}{d}[/tex]
=> [tex]2 * 0.015 = \frac{ \lambda * 4}{ 7.5 *10^{-3}}[/tex]
=> [tex]\lambda = 56250 *10^{-9} \ m[/tex]
=> [tex]\lambda = 56250 nm[/tex]
