Practice Problems
Thin Film Interference Soap Bubbles
Topics:
On this worksheet you will be investigating the basic properties of
thin film interference
in a soap bubble.
Page Directions
The numerical values in this worksheet are randomly generated allowing students the opportunity to conveniently practice, and drill, common situations.
Before beginning any given worksheet, please look over all of the questions and make sure that there are
no duplicate
answers shown for the same question. If duplicates are present simply refresh the page until every answer is unique.
In order to check an answer
(even when you are just starting the worksheet on Question 1)
it is
absolutely necessary
to
any questions that you have not answered. Once you start submitting answers, the page may be checked as many times as necesasary without changing the randomized answers. Relevant scoring will be provided at the top of the page only when you answer all of the questions on your original submission.
omit
Question 1
A thin soap bubble, n = 1.36, is filled with air. Since the medium outside the bubble is also air, at which of the interfaces (air-soap and soap-air) would the light undergo a 180° phase change upon reflection?
soap-air
at both interfaces
air-soap
at neither interface
omit
Question 2
What is the wavelength of red, 666-nm light as it travels through the film?
666 nm
906 nm
490 nm
omit
Question 3
At what minimum non-zero thickness of the film will the intensity of the red light reflected back into the air be a maximum?
122 nm
167 nm
245 nm
333 nm
omit
Question 4
At what minimum non-zero thickness of the film will the intensity of the same red light reflected back into the air be a minimum, or experience destructive interference?
333 nm
245 nm
167 nm
122 nm
omit
Question 5
In general, when red light is removed from white light, the soap bubble would appear to be which color?
yellow
magneta
grey
cyan
omit
Question 6
What is the frequency of the red light as it travels through the soap film?
1.47 x 10
20
hz
4.5 x 10
14
hz
6.13 x 10
-4
hz
3.31 x 10
14
hz
omit
Question 7
If the soap film were instead specified to be 604 nanometers thick, which wavelength in the visible spectrum would be canceled?
1.64 x 10
3
nm
4.11 x 10
2
nm
1.21 x 10
3
nm
8.88 x 10
2
nm
PhysicsLAB
Copyright © 1997-2026
Catharine H. Colwell
All rights reserved.
Application Programmer
Mark Acton