A Sodium Light, Having Wavelength 589

question 21

Multiple Choice

A sodium light, having wavelength 589.3 nm, is used to view a soap film to make it look black when directed perpendicular to the film. What is the minimum thickness of the soap film if the
Index of refraction of soap solution is 1.38?

• A) 314 nm
• B) 194 nm
• C) 214 nm
• D) 294 nm
• E) 114 nm

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