Exam 23: Wave Properties of Light

Light of wavelength 450 nm is incident on a narrow slit. The diffraction pattern is observed on a screen 5.0 m from the slit, and the central maximum is observed to have a width of 22 cm. What is the width of the slit?

The interference pattern is from a lens placed on a flat reflecting surface illuminated using a monochromatic light from above. From the pattern one can conclude that the lens

A helium-neon laser emits light of wavelength 632.8 nm and has a power output of 1.5 mW. How many photons are emitted per second by this laser?

Light travels in a medium of index of refraction n', passes into a medium of index n", where n" > n', and then into air, where n_air < n' < n". The ray that correctly shows the light path is

An "X" is marked on the bottom of a glass container. A microscope is adjusted so that it is focused on the "X." A liquid is now poured into the glass to a depth of 6.00 cm. If the microscope has to be backed up by a distance of 1.50 cm to refocus on the "X," then calculate the refractive index of the liquid.

As the width of the slit producing a single-slit diffraction pattern is slowly and steadily reduced always remaining larger than the wavelength of the light), the diffraction pattern

A broad spectrum of light λ = 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

A small beam of monochromatic light in air is incident on a large plate of glass with plane-parallel sides at an angle of 30º. The index of refraction of the glass plate for this wavelength is 1.50. The angle of emergence of the light on the far side of the plate is approximately

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. Partway 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.)

Which, if any, of the following conditions is not necessary for the light waves from two sources to be coherent?

You create a wedge-shaped film of air between two flat plates of glass 2.5 cm wide by laying one on top of the other and placing a small slip of paper 1.0 mm thick between their edges at one end. You illuminate the glass plates with normally incident monochromatic light of unknown wavelength. Observing the reflection, you see dark fringes at both ends of the plates. Between the ends you see three other dark fringes. What is the wavelength of the incident light?

You see a fish in water at an apparent depth of 1.83 m. The actual depth of the fish, if the index of refraction of the water relative to air is 4/3, must be

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.

The index of refraction of water is 1.33. The angle of incidence for maximum polarization by reflection is approximately

You illuminate two slits 0.50 mm apart with light of wavelength 555 nm and observe interference fringes on a screen 6.0 m away. What is the spacing between the fringes on the screen?

If the index of refraction of the glass plate shown is 1.45, the angle of incidence that will cause the unpolarized light to be reflected as completely plane-polarized light is

The optical phenomenon that is usually cited as demonstrating the transverse wave nature of light 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

A helium-neon laser emits light of wavelength 632.8 nm and has a power output of 3 mW. How many photons are emitted per second by this laser?

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