Exam 5 - Final

What is the frequency of an electromagnetic wave that has a wavelength of 300,000 km?

1 Hz

The function of polarizing filters in viewing 3-D slides or movies is to provide each eye A) an independent left or right-hand view. B) the ability to see parallax. C) a balanced intensity. D) a stereoscopic view. E) with light polarized at right angles to each other.

A) an independent left or right-hand view.

Light is emitted when A) electron clouds of atoms are forced into oscillation. B) high-frequency sound waves strike matter. C) atomic nuclei are made to vibrate. D) electromagnetic waves emanate from matter.

A) electron clouds of atoms are forced into oscillation.

Consider plane waves incident upon a barrier with a small opening. After passing through the opening, the waves A) fan out. B) continue as plane waves. C) converge. D) become polarized. E) all of these.

A) fan out

Colors seen when gasoline forms a thin film on water are a demonstration of A) interference. B) refraction. C) dispersion. D) reflection. E) polarization.

A) interference.

The sun is more likely to appear red at sunset than in the middle of the day as a result of the A) longer path of air through which sunlight travels. B) lower frequencies of light emitted late in the day by the sun. C) absorption effects of the smaller particles in the air. D) pollutants emitted by humans in daylight hours. E) scattering of lower frequencies by larger particles in the air.

A) longer path of air through which sunlight travels.

An atom that absorbs a photon of a certain energy can then emit A) only a photon of the same or lower energy. B) a photon of any energy. C) only a photon of that energy. D) only a photon of the same or higher energy.

A) only a photon of the same or lower energy.

The white light emitted by a fluorescent lamp is provided by the A) phosphors on the inner surface of the lamp. B) high temperature of the glowing gas. C) mercury vapor in the lamp. D) filtering effect of the glass tubing.

A) phosphors on the inner surface of the lamp.

Magenta light is really a mixture of A) red and blue light. B) red and yellow light. C) yellow and green light. D) red and cyan light. E) none of these.

A) red and blue light.

The twinkling of the stars is a result of atmospheric A) refraction. B) scattering. C) reflection. D) dispersion. E) aberrations.

A) refraction

The refraction of light in a diamond is greater for A) short-wavelength light. B) long-wavelength light. C) both refract the same.

A) short-wavelength light.

In an optical fiber, light actually A) travels in straight-line segments. B) travels along the outer surface of the fiber. C) curves in a direction parallel to the central axis of the fiber. D) all of these, depending on the type of fiber. E) none of these.

A) travels in straight-line segments.

Which of the following can be projected onto a viewing screen? A)a real image B)a virtual image C)both D) neither

A)a real image

The greater proportion of energy immediately converted to heat rather than light occurs in A)an incandescent lamp. B)a fluorescent lamp. C) both the same.

A)an incandescent lamp

Atoms of neon in a glass tube can be excited A)over and over again. B) once per atom.

A)over and over again

A surface that is considered rough for infrared waves may be polished for A)radio waves. B)light waves. C)both of these. D) none of these.

A)radio waves.

Polarization is a property of A)transverse waves. B) longitudinal waves. C) both. D) neither.

A)transverse waves

Colors seen on the cover of our physics book result from color A)subtraction. B) addition. C) either of these. D) neither of these.

A. Subtraction

When you view a soap film by white light coming from almost behind your head, you see a certain color. A friend on the other side of the film likely sees A)the same color. B) a different color.

B) a different color.

A property of non-cubic transparent crystals is that light travels through them A) in mutually perpendicular directions. B) at different speeds along different optic axes. C) and becomes polarized in the process. D) without refracting. E) none of these.

B) at different speeds along different optic axes.

Refraction causes the bottom of a swimming pool to appear A) farther down than it actually is. B) closer to the surface than it actually is. C) neither.

B) closer to the surface than it actually is.

The sky is the deepest blue A) just before a rainstorm. B) just after a rainstorm. C) when the air is humid. D) during a rainstorm. E) just before sunset.

B) just after a rainstorm.

Look at a full-color picture in a magazine with a magnifying glass and you'll see that the inks used are A) red, green, blue, and black. B) magenta, cyan, yellow, and black. C) red, green, and blue. D) magenta, cyan, and yellow. E) none of these.

B) magenta, cyan, yellow, and black.

The redness of the lunar eclipse is evidence for the A) scattering of lower frequencies of light by the moon. B) refraction of sunsets and sunrises all around the world. C) dim light that is incident upon the moon by Jupiter and other planets. D) faintly radiating atoms in our own atmosphere when sunlight is not incident upon them. E) infrared light continually emitted by the moon.

B) refraction of sunsets and sunrises all around the world.

When a mirror with a fixed beam on it is rotated through a certain angle, the reflected beam is rotated through an angle that is A)equal to the angle of rotation. B) twice as large. C) four times as large. D) none of these.

B) twice as large.

The polarization axes of ordinary sunglasses are A) horizontal. B) vertical. C) at right angles to each other.

B) vertical

Which will warm up quicker in sunlight? A)a piece of clear glass B)a piece of colored glass C) both the same

B)a piece of colored glass

When long-wavelength light is seen in the interference colors of a soap bubble, the wavelength being cancelled is relatively A)long. B)short. C) neither.

B)short.

Which of these electromagnetic waves has the shortest wavelength? A) ultraviolet waves B) X-rays C) infrared waves D) light waves E) radio waves

B. X-rays

Colors seen on TV result from color A)subtraction. B) addition. C) either of these. D) neither of these.

B. addition

Some double-pane airplane windows darken when the inner pane is rotated. The panes are A)thin films. B)optical fibers. C) Polaroid filters.

C) Polaroid filters.

The vibrational direction of the electron and the plane of polarization of the light it emits A) are independent of each other. B) are at right angles to each other. C) are the same. D) may or may not be at right angles to each other.

C) are the same.

A beam of light emerges from water into air at an angle. The beam is bent A) 48 degrees upward. B) towards the normal C) away from the normal. D) 96 degrees upward. E) not at all.

C) away from the normal.

Green light emitted by excited mercury vapor corresponds to a particular energy transition in the mercury atom. A more energetic transition might emit A)white light. B) either red or blue light. C) blue light. D) red light.

C) blue light.

Holograms employ the principle of A)interference. B) diffraction. C) both of these. D) neither of these.

C) both of these.

Interference colors in a soap bubble give evidence that the soap film A)has two reflecting surfaces. B) is thin. C) both of these. D) neither of these.

C) both of these.

Rainbows exist because light is A)reflected. B) refracted. C) both of these. D) neither of these.

C) both of these.

The law of reflection holds for A)plane mirrors. B) curved mirrors. C) both of these. D) neither of these.

C) both of these.

The yellow clothes of a stage performer can be made to look black if illuminated only by light that is A)blue. B) magenta plus cyan. C) both of these. D) none of these.

C) both of these.

The type of lens that spreads parallel light is a A) converging lens. B) combination converging-diverging lens. C) diverging lens.

C) diverging lens.

Materials can be heated until "red hot". If some material is heated until it is "green hot", then A) energy conservation would be violated. B) it would be hotter than "white hot". C) its molecules would be vibrating at nearly identical rates. D) it would liquify immediately. E) it would be a strong absorber of red light .

C) its molecules would be vibrating at nearly identical rates.

The incident light ray, the reflected light ray, and the normal between them A) may or may not lie in the same plane. B) lie in planes that are perpendicular to one another. C) lie in the same plane.

C) lie in the same plane.

Light will not pass through a pair of Polaroids when their axes are A) parallel. B) 45 degrees to each other. C) perpendicular. D) two of these. E) all of these.

C) perpendicular

The bending of light as it refracts actually A) has nothing to do with the time of travel. B) lengthens the time of travel. C) shortens the time of travel.

C) shortens the time of travel.

A traveling pulse of electromagnetic radiation is called a A)proton. B)lightron. C)photon. D)notron. E) sparktron.

C)photon

When the frequency of light matches the natural frequency of molecules in a material, light is A)transmitted. B)reflected. C)absorbed. D) none of these.

C. absorbed

Color depends on what characteristic of light? A)Its frequency B)Its wavelength C)both of these D) neither of these

C. both

The solar radiation curve is A) a plot of light intensity versus distance from the sun. B) the path taken by the sun as it travels around the Earth. C) a plot of the colors of sunlight versus their frequencies. D) a plot of brightness of sunlight versus its frequency. E) a dent in the otherwise spherical sun.

D) a plot of brightness of sunlight versus its frequency.

The greenish blue of water is evidence for the A) interaction between green and blue frequencies of light. B) reflection of red light. C) reflection of greenish-blue light. D) absorption of red light. E) absorption of greenish-blue light.

D) absorption of red light.

Newton's rings are a demonstration of A) reflection. B) dispersion. C) polarization. D) interference. E) refraction.

D) interference.

A person standing waist-deep in a swimming pool appears to have short legs because of light A) reflection. B) absorption. C) diffraction. D) refraction. E) interference.

D) refraction

Because of absorption, a Polaroid will actually transmit 40% of nonpolarized light incident on it. Two such Polaroids with their axes aligned will transmit A)16%. B)24%. C)30%. D)32%. E) 40%.

D)32%

A mirage occurs for road surfaces that are A)hard. B)cold. C)snowy. D)warm. E) wet.

D)warm

The colored dots that make up the color on a TV screen are A) red, green, yellow. B) red, blue, yellow. C) magenta, cyan, yellow. D) red, blue, green. E) yellow, blue, green.

D. red, blue, greed

Red sunsets are due to lower frequencies of light that A) are scattered from larger particles in the air. B) appear reddish orange to the eye. C) are reflected by clouds and relatively large particles in the air. D) survive being scattered in the air. E) are refracted from larger particles in the air.

D. survive being scattered in the air

The size of the pupil of your eye depends on A) the brightness of light in the room. B) the time of day. C) your mood. D) the temperature of the room. E) two of these.

E - A and D

A thin film appears blue when illuminated with white light. The color being cancelled by destructive interference is A) red. B) blue. C) green. D) white. E) none of these.

E) none of these.

Light from a laser is A)monochromatic. B) coherent. C) in phase. D) all of these.

E) none of these. D) all of these.

Light from a phosphorescent source A) normally has a shorter wavelength than the light that initially produced it. B) is cooler than light from a fluorescent source. C) takes longer to travel from the source to you. D) all of these.

E) none of these. E) none of these.

Most of the electromagnetic spectrum consists of visible light. t/f?

FALSE

light takes the path that requires the least time when it goes from one place to another

Fermat's principle of least time

Every point on a wave front can be regarded as a new source of wavelets, which combine to produe the next wave front, whose points are sources of further wavelets, and so on

Huygens' principle

distortion in an image produced by a lense which to some degree is present in all optical systems

aberration

the 3 colors - red, blue, and green - that when added in certain proportions produce any other color in the visible-light part of the electromagnetic spectrum and can be mixed equally to produce white

additive primary colors

any two colors that when added produce white light

complementary colors

a lens that is thicker in the middle than the edges, causing parallel rays to focus

converging lens

the minimum angle of incidence inside a medium at which a light ray is totally reflected

critical angle

the bending of light that passes around an obstacle or through a narrow slight, causing the light to spread

diffraction

reflection is irregular directions from an irregular surface

diffuse reflection

a lens that is thinner in the middle than at the edges, causing parallel rays to diverge from a point

diverging lens

the range of electromagnetic waves extending in frequency from radio waves to gamma rays

electromagnetic spectrum

energy carrying waveemmitted by vibrating charge (often electrons) that is composed of oscillating electric and magnetic fields that regenerate one another

electromagnetic wave

If the sun were to disappear right now, we wouldn't know about it for 8 minutes because it takes 8 minutes...

for light to travel from the sun to the Earth

If an electron vibrates up and down 1000 times each second, it generates an electromagnetic wave having a...

frequency of 1,000 Hz

the 2 dimensional microscopic interference patern that shows 3 dimensional optic images

hologram

Infrared waves are often called heat waves because they...

induce resonance in molecules and increase internal energy in a substance.

the result of superposing different waves, usually of the same wavelength. Constructive "x" results from crest-to-crest reinforcement; destructive "x" results from crest-to-trough cancellation. "x" of selected wavelengths of light produces colors knows an "x" colors.

interference

this equals the angle of incidence

law of reflection

Compared to its average speed in air, the average speed of a beam of light in glass is...

less

Compared to ultraviolet waves, the wavelength of infrared waves is...

longer

The moon would be at its fullest just before the time of a...

lunar eclipse

the event wherein the moon passes into the shadow of the earth

lunar eclipse

the term applied to materials through which light can pass in straight lines

opaque

a partial shadow that appears where some but not all of the light is blocked and other light can fall

penumbra

the alignment of the transverse electric vibrations of electromagnetic radiation. such waves of aligned vibrations are said to be "x"

polarization

an image formed by light rays that converge at the location of the image. a real image, unlike a virtual image, can be displayed on a screed

real image

The return of light rays from a surface

reflection

the bending of an oblique ray of light when it passes from one transparent medium to another

refraction

When ultraviolet light is incident upon glass, atoms in the glass...

resonate

a shaded region that appears where light rays are blocked by an object

shadow

the event wherein the moon blocks light from the sun and the moon's shadow falls on part of the earth

solar eclipse

the 3 colors of absorbing pigments - magenta, yellow, and cyan - that when mixed in certain proportions reflect any other color in the visible-light part of the electromagnetic spectrum

subtractive primary colors

Information-carrying nerves are connected to the retina at...

the blind spot

Consider light energy that is momentarily absorbed in glass and then re-emitted. Compared to the absorbed light, the frequency of the re-emitted light is...

the same

The speed of light in the void between molecules in glass is...

the same as its speed in a vacuum

the total reflection of light traveling within a denser medium when it strikes the boundary with a less dense medium at an angle greater than the critical angle

total internal reflection

The natural frequency of the atoms in glass is in the...

ultraviolet part of the spectrum

the darker part of a shadow where all the light is blocked

umbra

an image formed by light rays that do not converge at the location of the image

virtual image

The Earth's atmosphere is transparent to most waves in the...

visible part of the spectrum