Question

You are performing a double slit experiment very similar to the one from DL by shining a laser on two nattow slits spaced 7.5 x 103 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 clos center of the pattern is 1.5 cm, what is the wavelength of the laser?

Answer 1

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 $7.5 * 10^{-3}$ 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  $\lambda = 56250 nm$

Explanation:

From the question we are told that

   The  distance of slit separation is  $d = 7.5 *10^{-3} \ m$

   The  distance of the screen is  $D = 4 \ m$

    The  distance between the bright spot closest to the center of the interference  is  $k = 1.5 \ cm = 0.015 \ m$

   

Generally the width of the central  maximum fringe produced is mathematically represented as

        $y = 2 * k = \frac{ D * \lambda}{d}$

  =>    $2 * 0.015 = \frac{ \lambda * 4}{ 7.5 *10^{-3}}$

   =>   $\lambda = 56250 *10^{-9} \ m$

=>      $\lambda = 56250 nm$