AH physics exam tomorrow - help with waves question? thanks

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SUMMARY

The discussion centers on the interference of light waves, specifically addressing whether a half-wavelength (λ/2) optical path difference guarantees destructive interference. The original poster questions the validity of this assertion as suggested by the 2007 SQA past paper question 10. It is established that while a phase change of π (180 degrees) at one surface can lead to destructive interference, other parameters such as amplitude and wave coherence can influence the outcome, making the statement not universally true.

PREREQUISITES
  • Understanding of wave interference principles
  • Knowledge of optical path difference
  • Familiarity with phase changes in wave mechanics
  • Basic concepts of light wave properties
NEXT STEPS
  • Research the conditions for constructive and destructive interference in wave physics
  • Study the effects of amplitude on interference patterns
  • Learn about coherence length and its impact on wave interference
  • Examine the role of phase shifts in optical systems
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Students preparing for physics exams, particularly those focusing on wave mechanics and optical phenomena, as well as educators seeking to clarify concepts of wave interference.

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1. Homework Statement
If the optical path diff between two light waves is lambda/2 will they always interfere destructively? if this in true then wherever one wave undergoes aphase change of pi at one surface and the second wave does not then these two will always interfere destructively?

that's what the 2007 past paper question 10 suggests but i didnt think this was true
SQA answers:
ad%26pid%3D3%26fid%3DSent%26inline%3D1%26appid%3Dyahoomail&hash=dbf351e27334342ee385cb2d687ed0ba.png
https://us-mg6.mail.yahoo.com/ya/download?mid=2%5f0%5f0%5f2%5f4065%5fAGtL2kIAAA9%2bVUfn%2fgyiYFWt%2bYk&m=YaDownload&pid=3&fid=Sent&inline=1&appid=yahoomail

Homework Equations



In the attached question and SQA marking scheme

The Attempt at a Solution



If the optical path diff between two light waves is lambda/2 will they always interfere destructively? if this in true then wherever one wave undergoes aphase change of pi at one surface and the second wave does not then these two will always interfere destructively?[/B]thanks so much for any help - exam tomorrow :(
 
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What other parameter(s) of the waves would make this statement untrue?
 

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