GR0877 Problem 75
PROBLEM STATEMENT: This problem is still being typed.
SOLUTION: (B) The shift for the wave reflecting off the top surface of the film is (since the light is reflecting from a higher- medium). The shift for the wave reflecting off the bottom surface of the film is , where is the thickness of the film. Thus, . For constructive interference one has . But here is the wavelength in the medium, so we must replace it with : or . The film first appears bright for and . Then it appears bright for and and (nm).
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