Who we are
Impact
Student
Tutor
Question
Medium
Solving time: 3 mins
A soap film is held vertically in the air and is viewed in reflected light. Explain why the film appears to dark at the top.
Views: 5,668 students
Found 6 tutors discussing this question
Discuss this question LIVE
9 mins ago
Text solution
Verified
Due to gravity, the soap film tends to sag in its holder, being quite thin at the top and becoming thicker as one move toward the bottom of the holding ring. Because light reflecting from the front surface of the film experiences a phase change, and light reflecting from the back surface of the film does not change, the film must be a minimum of a half wavelength thick before it can produce constructive interference in the reflected light. Thus, the light must be striking the film at some distance from the top of the ring before the thickness is sufficient to produce constructive interference for any wavelength in the visible portion of the spectrum.
Was this solution helpful?
141
Share
Report
One destination to cover all your homework and assignment needs
Learn Practice Revision Succeed
Instant 1:1 help, 24x7
60, 000+ Expert tutors
Textbook solutions
Big idea maths, McGraw-Hill Education etc
Essay review
Get expert feedback on your essay
Schedule classes
High dosage tutoring from Dedicated 3 experts
Practice more questions from Wave Optics
Question 1
Hard
Views: 5,502
(a) the highest order of interference of light with wavelength λ = 0.50 p,m;
(b) the dispersion region Δλ , i.e. the spectral interval of wavelengths, within which there is still no overlap with other orders of interference if the observation is carried out approximately at wavelength λ = 0.50 pm.
Question 2
Medium
Views: 5,263
Question 3
Medium
Views: 5,506
Question 4
Easy
Views: 5,658
Practice questions on similar concepts asked by Filo students
Question 2
Views: 5,286
Question 3
Views: 5,890
Question 4
Views: 5,705
Stuck on the question or explanation?
Connect with our Physics tutors online and get step by step solution of this question.
231 students are taking LIVE classes
| Question Text | A soap film is held vertically in the air and is viewed in reflected light. Explain why the film appears to dark at the top. |
| Topic | Wave Optics |
| Subject | Physics |
| Class | Class 12 |
| Answer Type | Text solution:1 |
| Upvotes | 141 |
