Light is incident perpendicularly on four transparent films of different thickness. The thickness of each film is given in the drawings in terms of the wavelength λfilm of the light within the film. The index of refraction of each film is 1.5, and each is surrounded by air. Which film (or films) will appear bright due to constructive interference when viewed from the top surface, upon which the light is incident?
(a) 1, 2, 3, 4
(b) 2, 3
(c) 3
(d) 3, 4
(e) 4

Transcribed Image Text:

Light film 2 film 1.5 film 2ftm 4