Exam 35: Interference

A lens with a refractive index of 1.5 is coated with a material of refractive index 1.2 in order to minimize reflection. If $\lambda$ denotes the wavelength of the incident light in air, what is the thinnest possible such coating?

The reason there are two slits, rather than one, in a Young's experiment is:

Three experiments involving a thin film (in air) are shown. If t denotes the film thickness and $\lambda$ denotes the wavelength of the light in the film, which experiments will produce constructive interference as seen by the observer?

Light from a point source X contains only blue and red components. After passing through a mysterious box, the light falls on a screen. Red and blue hands are observed as shown. The box must contain:

The phase difference between the two waves which give rise to a dark spot in a Young's double-slit experiment is (where m = integer):

In a Young's double-slit experiment, the slit separation is doubled. To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to:

A light wave with an electric field amplitude of E₀ and a phase constant of zero is to be combined with one of the following waves. Which of these combinations produces the greatest intensity?

An air wedge is formed from two glass plates which are in contact at their left edges. There are ten dark bands when viewed by reflection using monochromatic light. The left edge of the top plate is now slowly lifted until the plates are parallel. During this process:

In a Young's double-slit experiment the center of a bright fringe occurs wherever waves from the slits differ in the distance they travel by a multiple of:

A glass (n = 1.6) lens is coated with a thin film (n = 1.3) to reduce reflection of certain incident light. If $\lambda$ is the wavelength of the light in the film, the least film thickness is:

A monochromatic light source illuminates a double slit and the resulting interference pattern is observed on a distant screen. Let d = center-to-center slit spacing, a = individual slit width, D = screen-to-slit distance, adjacent dark line spacing in the interference pattern. The wavelength of the light is then:

Monochromatic light, at normal incidence, strikes a thin film in air. If $\lambda$ denotes the wavelength in the film, what is the thinnest film in which the reflected light will be a maximum?

Units of "optical path length" are:

Waves from two slits are in phase at the slits and travel to a distant screen to produce the second minimum of the interference pattern. The difference in the distance traveled by the wave is:

In a thin film experiment, a wedge of air is used between two glass plates. If the wavelength of the incident light in air is 480 nm, how much thicker is the air wedge at the 16th dark fringe than it is at the 6th?

Interference of light is evidence that:

Red light is viewed through a thin vertical soap film. At the third dark area shown, the thickness of the film, in terms of the wavelength within the film, is:

A "wave front" is a surface of constant:

In a Young's double-slit experiment, light of wavelength 500 nm illuminates two slits which are separated by 1 mm. The separation between adjacent bright fringes on a screen 5 m from the slits is:

Waves from two slits are in phase at the slits and travel to a distant screen to produce the third side maximum of the interference pattern. The difference in the distance traveled by the waves is: