Ch#24#Problem#set#solutions#Part#II#
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14. A soap bubble (n = 1.33) is floating in air. If the thickness of the bubble wall is 115 nm, what is the
wavelength of the visible light that is most strongly reflected?
15. Suppose the film shown in Figure 24.7 has an index of refraction of 1.36 and is surrounded by air on
both sides. Find the minimum thickness that will produce constructive interference in the reflected light
when the film is illuminated by light of wavelength 500 nm.
16. A thin film of oil (n = 1.25) is located on a smooth, wet pavement. When viewed perpendicular to the
pavement, the film appears to be predominantly red (640 nm) and has no blue color (512 nm). How thick is
the oil film?
There is a problem with this question that was unforeseen. Please
disregard this question.
17. A thin layer of liquid methylene iodide (n = 1.756) is sandwiched between two flat parallel plates of
glass (n = 1.50). What must be the thickness of the liquid layer if normally incident light with λ = 600 nm
in air is to be strongly reflected?
18. A transparent oil of index of refraction 1.29 spills on the surface of water (index of refraction 1.33),
producing a maximum of reflection with normally incident orange light (wavelength 600 nm in air).
Assuming the maximum occurs in the first order, determine the thickness of the oil slick.
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