Exam 13: Interference and Diffraction

A wedge-shaped film of air is formed by placing a glass plate on second flat glass plate. The wedge is then illuminated using a monochromatic light from above and a fringe pattern is shown. From the fringe pattern one can conclude that the surface of the first glass plate is

Light of wavelength 500 nm illuminates parallel slits and produces an interference pattern on a screen that is 1 m from the slits. In terms of the initial intensity I₀, the light's intensity in the interference pattern at a point for which the path difference is 100 nm is

A parallel beam of sodium light of wavelength 589 nm is normally incident on a diffraction grating. If the second order diffraction maximum is observed at 50.25 degrees to the normal, then calculate the number of lines per cm of the grating.

Two side-by-side coherent light sources radiate at 450 nm. The phase difference between these two sources at a point in space is 0.333 radians. The path difference between the two sources could be

The size of the smallest things that can be seen with an optical microscope is limited by diffraction. Which of the following could help a microscopist see smaller things?

Which of two diffraction gratings, one with N₁ and the other with N₂ slits per centimeter, has the greater resolving power if N₁ is greater than N₂?

An antenna for receiving television signals from a satellite has a diameter of 3 m. The signals have a wavelength of 24 cm. If the diameter of the antenna is reduced to 50 cm, for what signal wavelengths does the antenna still have the same angular resolution?

Which of the following statements concerning the interference pattern described by the phasor diagram is true?

In the figure, a beam of light from an underwater source is incident on a layer of carbon disulfide and the glass bottom of the container. Some of the refracted and reflected rays are shown in the diagram. For the rays shown, the interface at which the reflected light changes phase is

In a double slit experiment, a very thin plate of glass of refractive index 1.58 is placed in the light path of one of the slit beams. When this was done, the center of the fringe pattern was displaced by 35 fringe widths. Calculate the thickness of the glass plate if the wavelength of light is 680 nm.

In demonstrating single-slit Fraunhofer diffraction, decreasing the wavelength of the light while keeping the slit width constant

A diffraction grating has 2000 lines per centimeter and is 3.0 centimeters wide. When visible light is incident on the grating, a maximum is observed at an angle of 10º from the normal. The wavelength of the incident radiation is

Suppose you observe fifteen bright fringes in the central maximum of a double-slit interference pattern. If you know that the separation of the slits d = 0.01 mm, you can conclude that the width of each slit is

Why are fringes not observed if the angle of the wedge of air in the diagram is too large?

The pupil of the human eye has a diameter of about 5 mm. When the wavelength of light incident on the pupil is 500 nm, the smallest angular separation of two resolvable sources is approximately

The yellow line of a Sodium lamp is two lines very close together at $\lambda$ ₁ = 589.592 nm and $\lambda$ ₂ = 588.995 nm. A diffraction grating with 10,000 lines/cm is used to resolve the lines. What is the angular separation of the two lines for the first order diffraction?

The yellow line of a Sodium lamp is two lines very close together at $\lambda$ ₁ = 589.592 nm and $\lambda$ ₂ = 588.995 nm. If a diffraction grating has to resolve the first order diffraction lines by an angular separation of 0.1 $\degree$ , what is the least number of lines per cm for the diffraction grating?

Two slits of width a = 0.020 mm are separated by a distance d = 0.05 mm and illuminated by light of wavelength $\lambda$ = 500 nm. The number of bright fringes seen in the central maximum is

You set two parallel slits 0.1 mm apart at a distance of 2 m from a screen and illuminate them with light of wavelength 450 nm. The distance between a bright spot in the interference pattern and the dark spot adjacent to it is

Two side-by-side coherent light sources radiate at 633 nm. At a point in space where the path difference to these two sources is 30 nm, the phase difference could be