Young's double slit and interference maximums

In summary: Use the given information and the equations to solve for the requested values.In summary, we are given the width of each slit, a, and the distance between the centers of the slits, d, in a Young's double slit experiment. We are asked to find the ratio of the slit separation distance to the width, the number of interference maximums across the central diffraction maximum, and the ratio of the intensity of the 5th interference maximum to the intensity of the central maximum. To solve for these values, we can use equations for the angle of diffraction, phi, and the angle of interference, beta, as well as equations for the intensity of single-slit diffraction and interference maximums. By using the given information and
  • #1
DWill
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0

Homework Statement


In a Young's double slit experiment the width of each slit is a, the distance between the centers
of the slits is d, and the 10th interference maximum to the right of the central maximum is the first
missing maximum. a) Find the ratio of the slit separation distance to the width, d
a
b) Find the number of interference maximums across the central diffraction maximum.
c) Find the ratio of the intensity of the 5th interference maximum relative to intensity of the
central maximum.


Homework Equations


phi = (2pi / lambda) * d * sin(theta)
beta = (2pi / lambda) * a * sin(theta)


The Attempt at a Solution


(a) I see that the ratio d/a is phi/beta, but how do I determine the value of phi and beta? All I can think of is that the 1st minimum occurs at beta = 2pi, but I'm not sure how that would relate here.
(b) No idea on this one
(c) There's a long equation for I that relates it to I_o. It also includes cos^2 (phi/2) and also sin(beta/2), and is too long and I'm not sure how to write it here. I can figure this out I think if I know the value of either phi or beta, and then use the d/a ratio from part (a) to find the other value. Once I have those 2 I can use the equation to relate the 5th interference maximum intensity to I_o (central max intensity).

Some explanations will also be greatly appreciated!
 
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  • #2
Your textbook should have an equation for the intensity of a single-slit diffraction pattern. You will need that.

There should also be an equation for the interference maximums.
 
  • #3


I can provide some insight on the Young's double slit experiment and the concept of interference maximums. In this experiment, light from a single source is passed through two narrow slits, creating two coherent light sources. The light from these sources then interferes with each other, producing a pattern of light and dark fringes on a screen placed behind the slits.

(a) The value of phi and beta can be determined using the equations given in the problem, where lambda is the wavelength of the light and theta is the angle at which the interference pattern is observed. The value of phi can be calculated using the distance between the centers of the slits (d) and the angle (theta) at which the 10th interference maximum is observed. Similarly, the value of beta can be calculated using the width of each slit (a) and the same angle (theta). Once the values of phi and beta are known, the ratio d/a can be calculated.

(b) The number of interference maximums across the central diffraction maximum can be determined by using the equation m = (d/a) * (lambda/d), where m is the number of maximums. In this case, m = 10, so the number of maximums across the central maximum would be 10.

(c) The intensity of the 5th interference maximum can be calculated using the equation I = I_o * cos^2 (phi/2) * sin^2 (beta/2), where I_o is the intensity of the central maximum. The value of phi and beta can be calculated using the values obtained in part (a). Using this equation, the ratio of the intensity of the 5th interference maximum to the intensity of the central maximum can be determined.

I hope this helps in understanding the concepts of Young's double slit experiment and interference maximums.
 

1. What is Young's double slit experiment?

Young's double slit experiment is a classic demonstration of the wave nature of light. It involves shining a coherent light source, such as a laser, through two closely spaced slits onto a screen. The resulting pattern of light and dark fringes is known as an interference pattern.

2. How does Young's double slit experiment demonstrate interference?

In Young's double slit experiment, the light waves from the two slits interfere with each other, creating areas of constructive interference where the waves reinforce each other and areas of destructive interference where they cancel each other out. This results in a pattern of bright and dark fringes on the screen.

3. What is the relationship between the spacing of the slits and the interference pattern?

The spacing between the slits and the distance to the screen determine the spacing of the fringes in the interference pattern. The closer the slits are to each other, the wider the fringes will be, and the farther the screen is from the slits, the closer together the fringes will be.

4. What is the difference between interference maximums and minimums?

In Young's double slit experiment, interference maximums refer to the bright fringes in the interference pattern where the light waves reinforce each other. Interference minimums, on the other hand, refer to the dark fringes where the light waves cancel each other out.

5. How is Young's double slit experiment used in modern technology?

The principles of Young's double slit experiment are used in various technologies, such as diffraction gratings in spectrometers and interferometers in telecommunications. It is also used in the study of quantum mechanics to understand the wave-particle duality of matter and light.

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