Double-Slit Arrangement With Plastic Sheet

In summary, the conversation discusses the double-slit arrangement and a sheet of transparent plastic placed over the upper slit. This results in a shift of the central maximum of the interference pattern. The presence of the plastic adds to the effective path length, causing a phase difference between the light passing through the upper and lower slits. This can be calculated using the general wave equation and taking into account the refractive index of the plastic.
  • #1
Ellipses
17
0

Homework Statement


Consider the double-slit arrangement shown in the figure below, where the separation d is 0.280mm and the distance L is 1.16m. A sheet of transparent plastic (n = 1.50) 0.0513mm thick (about the thickness of a piece of paper) is placed over the upper slit. As a result, the central maximum of the interference pattern moves upward a distance y'. What is y'?

Homework Equations


PD / d = xL
n = c/v

The Attempt at a Solution


I'm sorry. but I have absolutely no idea how to approach this. I've just been looking through my books and trying to find equations to plug the given information into, but no dice. Any help would be greatly, greatly appreciated. Thank you so much!
 
Physics news on Phys.org
  • #2
The presence of the plastic sheet results in a additional phase shift of the light passing through the upper slit relative to the light passing through the lower slit.
This means that their phase difference has now changed.
 
  • #3
How would I go about calculating that phase difference? Should I use the general wave equation?
 
  • #4
Ellipses said:
How would I go about calculating that phase difference? Should I use the general wave equation?
The plastic adds to the effective path length (refractive index of plastic - index of air)*thickness.
 
  • #5
When the light waves travel through an optically denser medium, they are slowed down - and so they travel more "cycles" (ie oscillate more cycles) in passing through that medium as compared to traveling the same distance in air.
Say I have two light waves initially in phase. One travels a distance L through air. The other travels the same distance L, but through a medium of refractive index n > 1. The effective optical length traveled by the second wave is in fact nL, and so there is a path difference of (nL-L) between the two waves.
 

1. What is a double-slit arrangement with plastic sheet?

A double-slit arrangement with plastic sheet is an experiment that involves shining a light source through two narrow slits in a plastic sheet and observing the resulting interference pattern on a screen.

2. How does the double-slit arrangement with plastic sheet work?

The double-slit arrangement with plastic sheet works by allowing light to pass through two narrow slits in a plastic sheet, causing the light to diffract and interfere with itself, resulting in a pattern of bright and dark fringes on a screen.

3. What is the purpose of using a plastic sheet in the double-slit arrangement?

The plastic sheet serves as a barrier for the light to pass through, creating two distinct slits for the light to diffract through. It also helps to ensure that the slits are evenly spaced and aligned, allowing for a clearer interference pattern.

4. What can the double-slit arrangement with plastic sheet tell us about light?

The double-slit arrangement with plastic sheet demonstrates the wave-like nature of light, as it produces an interference pattern similar to that of water waves passing through two slits. It also shows that light can behave as both a wave and a particle.

5. How is the double-slit arrangement with plastic sheet used in other fields of science?

The double-slit arrangement with plastic sheet is used in various fields of science, such as optics, quantum mechanics, and even biology. It is commonly used to study the properties of light and to demonstrate the principles of interference and diffraction. It has also been used to understand the behavior of electrons and other particles at the atomic level.

Similar threads

  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
5K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
6K
  • Introductory Physics Homework Help
Replies
5
Views
3K
  • Introductory Physics Homework Help
Replies
2
Views
2K
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
3K
  • Introductory Physics Homework Help
Replies
8
Views
2K
Back
Top