Question

A wire loop 20 cm high is dipped in soap solution and then held vertically to produce a film whose thickness increases linearly from 0 at the top to 1.0 um at the bottom. The film's refractive index is that of water, n = 1.333. See the figure .

If the film is illuminated with white light, what portion of it will appear dark?

Choose One Answer:
A)The top 7.5% of the film is dark.
B)The top 15.0% of the film is dark.
C)The top 22.5% of the film is dark.
D)The top 52.5% of the film is dark.

Answer 1