Question

Yellow light of 570 nm is reflected from a thin film of air between two glass plates. The thickness of the film is 1.71 ?m (1710 nm).

a. How much farther does the light reflected from the bottom surface of the film travel than that reflected from the top surface?

b. How many wavelengths of light does this represent?

Answer 1

3 x 570nm = 1710nm



the light has to travel \(3 \lambda 's\) to the bottom and another 3 to get back up = \(6 \lambda\)