Exam 35: Interference

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

In an experiment to measure the wavelength of light using a double slit, it is found that the fringes are too close together to easily count them. To spread out the fringe pattern, one could:

To obtain an observable double-slit fringe pattern:

When light travels from one medium into a different medium with a different index of refraction,

In a Young's experiment, it is essential that the two beams:

In a Young's double-slit experiment, a thin sheet of mica is placed over one of the two slits. As a result, the center of the fringe pattern (on the screen) shifts so that the center is now occupied by what was the 30^th dark band. The wavelength of the light in this experiment is 480 nm and the index of the mica is 1.60. The mica thickness is:

In a Young's double-slit experiment the center of a bright fringe occurs wherever waves from the slits differ in phase 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:

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:

A thin film with an index of refraction of 1.60 is placed in one of the beams of a Michelson interferometer. If this causes a shift of 8 bright fringes in the pattern produced by light of wavelength 580 nm, what is the thickness of the film?

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

A soap film is illuminated by white light normal to its surface. The index of refraction of the film is 1.50. Wavelengths of 480 nm and 800 nm and no wavelengths between are intensified in the reflected beam. The thickness of the film is:

A liquid of refractive index n = 4/3 replaces the air between a fixed wedge formed from two glass plates as shown. As a result, the spacing between adjacent dark bands in the interference pattern:

Yellow light is viewed by reflection from a thin vertical soap film. Let $\lambda$ be the wavelength of the light within the film. Why is there a large dark space at the top of the film?

One of the two slits in a Young's experiment is painted over so that it transmits only one-half the intensity of the other slit. As a result:

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?

Light from a small region of an ordinary incandescent bulb is passed through a yellow filter and then serves as the source for a Young's double-slit experiment. Which of the following changes would cause the interference pattern to be more closely spaced?

If two light waves are coherent:

Binoculars and microscopes are frequently made with coated optics by adding a thin layer of transparent material to the lens surface as shown, in order to improve light transmission. One wants:

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: