A thin film with index of refraction ny separates two materials, each of which has an index of refraction less than nf. A monochromatic beam of light is incident normally on the film. If the light has wavelength A within the film, maximum constructive interference between the incident beam and the reflected beam occurs for which of the following film thicknesses? I. 3A II. A III. X/2 (1) I, II, and III (2) III only (3) II only (4) I only thin film |light (5) I and II only n₁ < n₁ ne n₂< n {

A thin film with index of refraction ny separates two materials, each of which has an index of refraction less than nf. A monochromatic beam of light is incident normally on the film. If the light has wavelength A within the film, maximum constructive interference between the incident beam and the reflected beam occurs for which of the following film thicknesses? I. 3A II. A III. X/2 (1) I, II, and III (2) III only (3) II only (4) I only thin film |light (5) I and II only n₁ < n₁ ne n₂< n {