Exam 13: Interference and Diffraction

Two side-by-side coherent light sources radiate at 600 nm. The phase difference between these two sources at a point in space is 0.582 radians. The path difference between the two sources could be

Which of the following statements is true?

A broad spectrum of light ( $\lambda$ = 550 nm) illuminates normally a thin wedge of glass (n = 1.50). If the thick edge of the glass is 0.02 mm, the number of dark fringes observed is

Five coherent sources are used to produce an interference pattern. The phasor diagram shown could be used to calculate the intensity of the

Which of the phasor diagrams shows the first minimum for five equally spaced in-phase sources?

At normal incidence, the minimum thickness of a soap film (n = 1.33) that causes constructive interference when viewed by reflected light of wavelength 400 nm is

In accordance with the Rayleigh criterion, two points can be just resolved if the centers of their diffraction patterns are separated by

Diffraction of sound waves is more readily observable than that of light waves because

Two flat planes of glass are laid on top of one another. The upper plane is slightly raised due to the insertion of a thin piece of paper at one end and an air wedge is thus formed. Light of wavelength 500 nm is normally incident on the glass from above and interference fringes are observed by reflection with 2.5 fringes per cm. Calculate the angle of the wedge.

Red light ( $\lambda$ = 700 nm) is incident normally on a diffraction grating having 1000 lines/cm. A maximum is observed at a deflection angle of 12º. The order in which this occurs is

In order to produce several visible interference fringes from two narrow slits using light of a single wavelength, the distance between the slits must be of the order

A 3.5-cm-long microscope glass slide has one edge in contact with a flat plane of glass, while the other edge is slightly raised due to the insertion of a thin piece of paper. Sodium light of wavelength 589 nm is normally incident on the glass from above and interference fringes are observed by reflection with a regular spacing of 0.22 mm. Calculate the thickness of the piece of paper.

The phase difference for the two waves shown in the figure is

The diffraction pattern of a single slit is shown in the figure. The point at which the path difference of the extreme rays is two wavelengths is

A discharge tube is known to produce two spectral lines, one at 640 nm and the other at 640.4 nm. The total number of rulings that a grating must have to just resolve these lines in the second order is

You dip a wire loop into soapy water (n = 1.33) and hold it up vertically to look at the soap film in white light. The soap film looks dark at the top because it has sagged, and its thickness there is nearly zero, causing the reflected wavelengths to interfere destructively. Part way down the loop you see the first red band of the reflected white light. What is the thickness of the soap film there? (Take the wavelength of red light to be 680 nm.)

When the slits in Young's experiment are moved closer together, the fringes

For two identical rays of light to interfere destructively, their path lengths

The interference and diffraction envelopes of a double slit are shown separately but to the same scale in the figure. For this arrangement, the number of fringes in the second diffraction maximum is

The graphs are plots of relative intensities of various diffraction patterns versus the sine of the angle from the central maximum. The graph that represents the diffraction pattern from the widest single slit is