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qid 9577 · physics
Question: While examining the surface of a polishedworkpieceby interferometryusing thallium light of wavelength 535 nm, it is found that in a certain area on the surface the fringes are distorted by 0.4 of the distance between the undistorted fringes. What is the depth, or elevation, of the defect?
- 0.8 × 2.675 × 10^-7m
- 0.2 × 535 × 10^-9m
- 2.14 × 10^-4mm
- 0.4 × 535 × 10^-7m
- 2.675 × 10^-7m
- 1.07 × 10^-4mm
- 0.4 × 535 × 10^-6m
- 535 × 10^-9m
- 0.4 × 2.675 × 10^-7m
- 1.07 × 10^-6m
Our answer: F. 1.07 × 10^-4mm Source quote machine-checked (exact quote)
How it was answered
Stored method, replayed by code (kind: formula)
Current source
Wikipedia, "Optical flat"
https://en.wikipedia.org/wiki/Optical_flat
“Thus the bright and dark fringes alternate, with the separation between two adjacent bright or dark fringes representing a change in the gap length of one half wavelength (λ/2).”
Source quote machine-checked (exact quote)
Earlier version (superseded)
https://en.wikipedia.org/wiki/Optical_flat
Source weak (http_get_200_text_and_question_terms)
Earlier version (superseded)
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