Glencoe Physics: Principles & Problems, Student Edition: Unit Test 26-30 Flashcards

Most of the waves in the electromagnetic spectrum are

A) red light.
B) blue light.
C) green light.
D) invisible.

Electromagnetic waves consist of

A) compressions and rarefactions of electromagnetic pulses.
B) oscillating electric and magnetic fields.
C) particles of light energy.
D) high-frequency gravitational waves.

The fact that light travels at 300,000 km/s is a consequence of

A) electromagnetic wave propagation.
B) electromagnetic field induction.
C) Maxwell's laws.
D) energy conservation.
E) none of these

The source of all electromagnetic waves is

A) changes in atomic energy levels.
B) vibrating atoms.
C) accelerating electric charges.
D) crystalline fluctuations.
E) none of these

The main difference between a radio wave and a light wave is its

A) speed.
B) wavelength.
C) frequency.
D) all of these
E) two of these

Which of these electromagnetic waves has the shortest wavelength?

A) radio waves
B) infrared waves
C) X-rays
D) ultraviolet waves
E) light waves

Compared to ultraviolet waves, the wavelength of infrared waves is

A) shorter.
B) longer.
C) the same.

Compared to radio waves, the velocity of visible light waves in a vacuum is

A) less.
B) more.
C) the same.

If an electric charge is shaken up and down

A) sound is emitted.
B) light is emitted.
C) electron excitation occurs.
D) a magnetic field is created.
E) its mass decreases.

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

A) period of 1000 s.
B) speed of 1000 m/s.
C) wavelength of 1000 m.
D) frequency of 1000 Hz.
E) wavelength of 1000 km.

Which of the following is fundamentally different from the others?

A) sound waves
B) X-rays
C) gamma rays
D) light waves
E) radio waves

The natural frequency of the atoms in glass is in the

A) infrared part of the spectrum.
B) visible part of the spectrum.
C) ultraviolet part of the spectrum.

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

A) are forced into vibration.
B) resonate.
C) pass the light energy along practically undiminished.
D) freely absorb and re-emit most of the ultraviolet light.

When visible light is incident upon clear glass, atoms in the glass

A) are forced into vibration.
B) resonate.
C) convert the light energy into internal energy.

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

A) considerably less.
B) slightly less.
C) the same.
D) slightly more.
E) considerably more.

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

A) more than its speed in a vacuum.
B) the same as its speed in a vacuum.
C) less than its speed in a vacuum.

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

A) more.
B) less.
C) the same.

Infrared waves are often called heat waves because they

A) emanate from relatively hot sources.
B) consist of frequencies lower than those of visible light.
C) induce resonance in molecules and increase internal energy in a substance.
D) are absorbed rather than reflected by the skin.
E) are the predominant waves emitted by the sun.

Materials generally become warmer when light is

A) absorbed by them.
B) reflected by them.
C) transmitted by them.
D) all of these
E) none of these

Sunburns are produced by

A) ultraviolet light.
B) visible light.
C) infrared light.
D) all of these
E) none of these

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

A) infrared part of the spectrum.
B) visible part of the spectrum.
C) ultraviolet part of the spectrum.
D) entire electromagnetic spectrum.

A lunar eclipse occurs when the

A) sun passes into Earth's shadow.
B) moon passes into Earth's shadow.
C) Earth passes into the sun's shadow.
D) Earth passes into the moon's shadow.

A solar eclipse occurs when the

A) sun passes into Earth's shadow.
B) moon passes into the Earth's shadow.
C) the moon's shadow touches Earth.

A partial solar eclipse occurs for people in the sun's

A) umbra.
B) penumbra.
C) none of these

While Earth is experiencing a total solar eclipse, an observer on the side of the moon facing the Earth would see

A) Earth disappear from the sky.
B) Earth dim and turn reddish.
C) nothing unusual.
D) a tiny dark spot move across the face of Earth.

The sensation of color is seen when light falls on the eye's

A) rods.
B) cones.
C) both
D) neither

The cones in the retina of the eye are

A) most densely packed at the center of vision.
B) uniformly spread along the visual field.
C) concentrated along the periphery of vision.

Red-hot and blue-hot stars appear white to the eye because

A) the eye has difficulty seeing color at night.
B) they are too dim to fire the cones.
C) they are too dim to fire the rods.
D) they are overwhelmed by the blackness of the nighttime sky.
E) eye receptivity peaks in the yellow-green part of the spectrum.

In the periphery of our vision, we are

A) more sensitive to low frequencies than high ones.
B) insensitive to color and movement.
C) sensitive to movement, but cannot see color.
D) sensitive to both movement and color.
E) none of these

Information-carrying nerves are connected to the retina at

A) the fovea.
B) the blind spot.
C) the cornea.
D) the iris.
E) the periphery.

The size of the pupil of your eye depends on

A) the brightness of light in the room.
B) the temperature of the room.
C) the time of day.
D) your mood.
E) two of these

If a light signal and a radio signal were emitted simultaneously from Alpha Centauri, the first to reach Earth would be the

A) radio signal.
B) light signal.
C) both would reach Earth at the same time.

Which of the following cannot travel in a vacuum?

A) a light wave
B) a sound wave
C) a radio wave
D) All can travel in a vacuum.
E) None can travel in a vacuum.

The main difference between a radio wave and a sound wave is their different

A) frequencies.
B) wavelengths.
C) energies.
D) amplitudes.
E) modes of travel.

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

A) for the sun to disappear.
B) to operate receiving equipment in the dark.
C) for light to travel from the sun to the Earth.
D) all of these
E) none of these

Glass is transparent to wave frequencies that

A) match its natural frequencies.
B) are below its natural frequencies.
C) both of these
D) none of these

Glass is opaque to wave frequencies that

A) match its natural frequencies.
B) are below its natural frequencies.
C) both of these
D) none of these

A pair of sunglasses and a pair of clear reading glasses are left in the sunlight. The hotter glasses would be the

A) sunglasses.
B) reading glasses.
C) both
D) neither

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

A) solar eclipse.
B) lunar eclipse.
C) both of these
D) none of these

What is the wavelength of an electromagnetic wave that has a frequency of 1 hertz?

A) less than 1 m
B) 1 m
C) more than 1 m

What is the wavelength of an electromagnetic wave that has a frequency of 3 kilohertz?

A) less than 1 km
B) 1 km
C) more than 1 km

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

A) less than 1 Hz
B) 1 Hz
C) more than 1 Hz

The main difference between the retina of a human eye and that of a dog's eye is the

A) predominance of cones in a dog's retina.
B) absence of cones in a dog's retina.
C) more intricate optic nerve in a human's eye.
D) absence of cones in a human's eye.
E) none of these

Things seen by moonlight usually aren't colored because moonlight

A) doesn't have very many colors in it.
B) is too dim to activate the retina's cones.
C) photons don't have enough energy to activate the retina's cones.
D) all of these
E) none of these

At the same time an astronaut on the moon sees a solar eclipse, observers on Earth see

A) a lunar eclipse.
B) a solar eclipse.
C) no eclipse at all.

Color depends on what characteristic of light?

A) its frequency
B) its amplitude
C) both of these

When the frequency of light matches the natural frequency of molecules in a material, light is

A) absorbed.
B) transmitted.
C) reflected.
D) none of these

The color of an opaque object is the same as the light that is

A) transmitted.
B) absorbed.
C) reflected.
D) all of these
E) none of these

What color light is transmitted by a piece of blue glass?

A) red
B) white
C) blue
D) yellow
E) orange

The brightest color emitted by the sun is

A) red.
B) orange.
C) yellow-green.
D) green-blue.
E) violet.

The solar radiation curve is

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

Which will warm up quicker in sunlight?

A) a piece of colored glass
B) a piece of clear glass
C) both the same

Light shines on a pane of green glass and a pane of clear glass. The temperature will be higher in the

A) clear glass.
B) green glass.
C) Neither – it will be the same in each.

The colored dots that make up the color on a TV screen are

A) red, blue, yellow.
B) red, blue, green.
C) yellow, blue, green.
D) magenta, cyan, yellow.
E) red, green, yellow.

If three primary colors of light are to shine on a white wall to produce a white spot, the primaries must be

A) additive.
B) subtractive.
C) multiplicative.
D) divisive.

Complementary colors are two colors that

A) look good together.
B) are additive primary colors.
C) are subtractive primary colors.
D) produce white light when added together.
E) are right for each other.

The complementary color of blue is

A) red.
B) green.
C) yellow.
D) cyan.
E) magenta.

Magenta light is really a mixture of

A) red and blue light.
B) red and cyan light.
C) red and yellow light.
D) yellow and green light.
E) none of these

Colors seen on TV results from color

A) addition.
B) subtraction.
C) either of these
D) neither of these

Colors seen on the cover of our physics book result from color

A) addition.
B) subtraction.
C) either of these
D) neither of these

How many colors of ink are used to print full-color pictures?

A) one plus black
B) two plus black
C) three plus black
D) four plus black
E) six plus black

Different colors of light correspond to different light

A) velocities.
B) intensities.
C) polarities.
D) frequencies.
E) none of these

A mixture of red and green pigments appears

A) orange.
B) yellow.
C) magenta.
D) blue.
E) blackish brown.

A mixture of cyan and yellow pigments appears

A) orange.
B) green.
C) magenta.
D) blue.
E) blackish brown.

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, and blue.
B) red, green, blue, and black.
C) magenta, cyan, and yellow.
D) magenta, cyan, yellow, and black.
E) none of these

Which interacts more with sounds of relatively high frequencies?

A) large bells
B) small bells
C) both the same

Which interacts more with light of relatively high frequencies?

A) large particles
B) small particles
C) both the same

The sky is blue because air molecules in the sky act as tiny

A) mirrors which reflect only blue light.
B) resonators which scatter blue light.
C) sources of white light.
D) prisms.
E) none of these

A whitish sky is evidence that the atmosphere contains

A) predominantly small particles.
B) predominantly large particles.
C) a mixture of particle sizes.
D) water vapor.
E) pollutants.

Sunsets are red, blue jays are blue; the reason's the same:

A) scattered sunlight – nothing new.
B) pigments that reflect in the blue.
C) aerosols and all such goo.
D) no one knows, but it is true.

The sky is the deepest blue

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

Red sunsets are due to lower frequencies of light that

A) are scattered from larger particles in the air.
B) are refracted from larger particles in the air.
C) are reflected by clouds and relatively large particles in the air.
D) survive being scattered in the air.
E) appear reddish orange to the eye.

The sun is more likely to appear red at sunset than in the middle of the day as a result of the

A) scattering of lower frequencies by larger particles in the air.
B) longer path of air through which sunlight travels.
C) lower frequencies of light emitted late in the day by the sun.
D) pollutants emitted by humans in daylight hours.
E) absorption effects of the smaller particles in the air.

A variety of sunset colors is evidence for a variety of

A) elements in the sun.
B) apparent atmospheric thicknesses.
C) atmospheric particles.
D) atmospheric temperatures.
E) primary colors.

The whiteness of clouds is evidence in the clouds for a variety of

A) particle sizes.
B) molecules.
C) "seeds" upon which condensation of cloud material forms.
D) light intensities.
E) water prisms.

The greenish blue of water is evidence for the

A) reflection of greenish-blue light.
B) reflection of red light.
C) absorption of greenish-blue light.
D) absorption of red light.
E) interaction between green and blue frequencies of light.

The part of the electromagnetic spectrum most absorbed by water is

A) infrared.
B) lower frequencies in the visible.
C) middle frequencies in the visible.
D) higher frequencies in the visible.
E) ultraviolet.

A red crab very deep in water, where sunlight is dim, appears

A) red.
B) orange.
C) cyan.
D) brown.
E) no color – black.

A sheet of red paper will look black when illuminated with

A) red light.
B) yellow light.
C) magenta light.
D) cyan light.
E) none of these

A blue object will appear black when illuminated with

A) blue light.
B) cyan light.
C) yellow light.
D) magenta light.
E) none of these

If sunlight were green instead of white, the most comfortable color to wear on a hot day would be

A) magenta.
B) yellow.
C) green.
D) blue.
E) violet.

If sunlight were green instead of white, the most comfortable color to wear on a cold day would be

A) magenta.
B) yellow.
C) green.
D) blue.
E) violet.

Distant dark colored hills appear blue because that is the color of the

A) atmosphere between the observer and the hills.
B) selectively reflected light that reaches a distant observer.
C) reflected light that survives scattering.
D) sky that is reflected off the hills.

Distant snow covered hills appear yellowish because that is the color of the

A) atmosphere between the observer and the hills.
B) selectively reflected light that reaches a distant observer.
C) reflected light that survives scattering.
D) sky that is reflected off the hills.

If molecules in the sky scattered orange light instead of blue light, sunsets would be colored

A) orange.
B) yellow.
C) green.
D) blue.
E) none of these

If the atmosphere were about 40 times thicker, at noon the sun would appear

A) red-orange.
B) orange-green.
C) green-blue.
D) blue-violet.
E) none of these

The atmosphere of Jupiter is more than 1000 km thick. From the planet's surface, the noon-day sun would appear

A) white.
B) faintly white.
C) not at all.
D) none of these

On a planet where atmospheric gases are red, distant dark colored hills would look

A) bluish.
B) greenish.
C) yellowish.
D) reddish.
E) untinted.

On a planet where atmospheric gases are yellow, distant snow covered hills would look

A) bluish.
B) greenish.
C) yellowish.
D) reddish.
E) untinted.

The redness of the lunar eclipse is evidence for the

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

Light is emitted when

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

Light will almost always travel from one place to another along a path of least

A) distance.
B) time.
C) effort.
D) expense.
E) complication.

The incident light ray, the reflected light ray, and the normal between them

A) lie in the same plane.
B) may or may not lie in the same plane.
C) lie in planes that are perpendicular to one another.

Object and image for a plane mirror lie

A) along the same plane.
B) equal distances from the mirror.
C) at right angles to each other.
D) all of these
E) none of these

The amount of light reflected from the front surface of a common windowpane is about

A) 4 percent.
B) 8 percent.
C) 40 percent.
D) 92 percent.
E) 96 percent.

Diffuse reflection occurs when the size of surface irregularities is

A) small compared to the wavelength of the light used.
B) large compared to the wavelength of the light used.
C) microscopic.

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

When light reflects from a surface, there is a change in its

A) frequency.
B) wavelength.
C) speed.
D) all of these
E) none of these

If you walk towards a mirror at a certain speed, the relative speed between you and your image is

A) half your speed.
B) your speed.
C) twice your speed.
D) none of these

The shortest plane mirror in which you can see your entire image is

A) half your height.
B) about 3/4 your height.
C) about 1/3 your height.
D) equal to your height.
E) dependent on your distance from the mirror.

To see his full height, a boy that is 1 meter tall needs a mirror that is at least

A) 0.33 m tall.
B) 0.50 m tall.
C) 0.75 m tall.
D) 1 m tall.
E) depends on how far the mirror is from the boy

You wish to photograph the image of your little sister, who is standing 2 meters from a plane mirror. Holding the camera beside her head, you should set the distance for

A) 1 meter.
B) 2 meters.
C) 3 meters.
D) 4 meters.
E) none of these

A diver shines light up to the surface of a smooth pond at a 10-degree angle to the normal. Some light passes into the air above, and the part that reflects back into the water makes an angle to the normal of

A) less than 10 degrees.
B) 10 degrees.
C) more than 10 degrees.

A yellow-white candle flame reflected from a piece of red glass shows two images; one from each surface.

A) Both images are yellow-white.
B) One image is yellow-white and the other red.
C) Both images are red.
D) Both images are reddish yellow.

When you look at yourself in a pocket mirror, and then hold the mirror farther away, you see

A) more of yourself.
B) less of yourself.
C) the same amount of yourself.

It is difficult to see the roadway in front of you when you are driving on a rainy night mainly because

A) light scatters from raindrops and cuts down the light to reach your eyes.
B) of added condensation on the inner surface of the windshield.
C) the film of water on your windshield provides an additional reflecting surface.
D) the film of water on the roadway makes the road less diffuse.
E) none of these

Standing at the shore of a still lake, the reflected view of scenery on the far side of the lake is the view you would see if you were upside down with your eye in the line of sight

A) where it already is.
B) at the surface of the water where the light reflects.
C) directly beneath you, as far below water level as you are above.
D) close to the distant shore.
E) none of these

Figure 28-A

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

The inversion of your image in a plane mirror is actually an inversion of

A) left-right.
B) up-down.
C) front-back.
D) all of these

Figure 28-B

Reflected light from the moon in a lake often appears as a vertical column when the water is

A) perfectly still.
B) slightly rough.
C) very rough - churning with waves.

Ninety-five percent of light incident on a mirror is reflected. How much light is reflected when three of these mirrors are arranged so light reflects from one after the other?

A) 81%
B) 85%
C) 86%
D) 90%
E) 95%

Figure 28-C

Two plane mirrors are at right angles to each other. A coin placed near the mirrors has at most

A) 2 images.
B) 3 images.
C) 4 images.
D) more than 4 images.

As a light ray enters or exits a water-air interface at an angle of 15 degrees with the normal, it

A) always bends toward the normal.
B) always bends away from the normal.
C) sometimes bends towards the normal.
D) does not bend.

When light passes through an ordinary window pane, its angle of emergence is

A) usually less than its angle of incidence.
B) always less than its angle of incidence.
C) the same as its angle of incidence.
D) usually more than its angle of incidence.
E) always more than its angle of incidence.

Light travels fastest in

A) warm air.
B) cool air.
C) a vacuum.

Atmospheric refraction makes the daylight hours a bit

A) longer.
B) shorter.
C) longer in summer but shorter in winter.

A mirage is a result of atmospheric

A) reflection.
B) refraction.
C) scattering.
D) dispersion.
E) aberrations.

The twinkling of the stars is a result of atmospheric

A) reflection.
B) refraction.
C) scattering.
D) dispersion.
E) aberrations.

Refraction results from differences in light's

A) frequency.
B) incident angles.
C) speed.
D) all of these
E) none of these

Light refracts when traveling from air into glass because light

A) has greater intensity in air than in glass.
B) has greater intensity in glass than in air.
C) has greater frequency in air than in glass.
D) has greater frequency in glass than in air.
E) travels slower in glass than in air.

At night an underwater scuba diver aims his flashlight beam toward the surface at an angle of 15 degrees with the normal. Upon emerging, the beam angle will be

A) less than 15 degrees.
B) 15 degrees.
C) more than 15 degrees.
D) impossible to predict.

When a light beam emerges from water into air, the average light speed

A) increases.
B) decreases.
C) remains the same.

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.

The average speed of light is greatest in

A) red glass.
B) orange glass.
C) green glass.
D) blue glass.
E) is the same in all of these

Different colors are dispersed by a prism because different colors in the prism have different

A) frequencies.
B) speeds.
C) directions.
D) energies.
E) none of these

Rainbows are not usually seen as complete circles because

A) the ground is usually in the way.
B) they are actually elliptical.
C) they have no bottom part.
D) raindrops are not perfectly round.
E) rainbows are actually arched shaped.

A single raindrop illuminated by sunshine disperses

A) a single color.
B) either low-, middle-, or high-frequency colors in most cases.
C) all the colors of the rainbow.

When you view a distant rainbow, each single water drop contributes to the bow

A) a single color.
B) either low-, middle-, or high-frequency colors in most cases.
C) all the colors of the rainbow.

The secondary rainbow is dimmer than the primary rainbow because

A) its colors are inverted.
B) it is larger, and its energy is spread over more area.
C) it is farther from the viewer.
D) it simply has much less energy than the primary bow.
E) of an extra reflection and refraction in the drops.

The critical angle for a transparent material is the angle at and beyond which all light within the material is

A) refracted.
B) reflected.
C) absorbed.
D) dispersed.
E) diffused.

The critical angle is least in which of the following?

A) glass
B) water
C) diamond
D) vacuum

In optical fibers of uniform density, light actually

A) curves in a direction parallel to the central axis of the fiber.
B) travels in straight-line segments.
C) travels along the outer surface of the fiber.
D) None of the above choices are correct.

Optical fibers are now used by

A) surgeons.
B) mechanics.
C) engineers.
D) all of these

Your image in a plane mirror is

A) virtual.
B) real.
C) both of these
D) neither of these

The type of lens that spreads parallel light is a

A) converging lens.
B) diverging lens.
C) combination converging-diverging lens.

Which of the following can be projected onto a viewing screen?

A) a real image
B) a virtual image
C) both
D) neither

A "burning glass" used to concentrate sunlight in a tiny spot is a

A) converging lens.
B) diverging lens.
C) either
D) neither

The image of the "infinitely-far-away" sun produced by a converging lens appears

A) between the lens and the focal point.
B) at the focal point.
C) beyond the focal point.

Figure 28-D

The image in a pinhole camera is

A) always inverted.
B) sometimes inverted.
C) always right-side up.

When the pinhole in a pinhole camera is made larger, the image is

A) brighter.
B) clearer.
C) both
D) neither

Your vision is sharpest when your pupil is

A) dilated.
B) constricted.
C) same either way.

Chromatic aberration is absent in

A) converging lenses
B) diverging lenses.
C) front surface plane mirrors.

Chromatic aberration is a consequence of different colors in a lens having different

A) aberrations.
B) frequencies.
C) energies.
D) critical angles.
E) speeds.

When a light ray passes at a non-90 degree angle from water into air, it

A) bends toward the normal.
B) bends away from the normal.
C) travels much slower.

Fermat's principle of least time applies to

A) reflection.
B) refraction.
C) both of these
D) neither of these

Fermat's principle of least time could also be the principle of least distance for the case of

A) reflection.
B) refraction.
C) both of these
D) neither of these

A beam of light travels fastest in

A) glass.
B) water.
C) plastic.
D) air.
E) is the same in each of these

When seen from an airplane, a rainbow sometimes forms a complete circle. When this happens, the plane's shadow is

A) in the center of the rainbow.
B) in the lower part of the rainbow.
C) in the upper part of the rainbow.
D) totally outside the rainbow.
E) nowhere, for there is no shadow.

A fish outside water will see better if it has goggles that are

A) tinted blue.
B) hemispheres.
C) filled with water.
D) extremely shiny.
E) none of these

Which of the following are consequences of light's traveling at different speeds in different media?

A) mirages
B) rainbows
C) internal reflection
D) all of these
E) none of these

Stars twinkle when seen from the Earth. When seen from the moon, stars

A) twinkle more.
B) twinkle less.
C) don't twinkle.

Atmospheric refraction tends to make daytimes

A) longer.
B) shorter.
C) no change in day length

If a fish looks upward at 45 degrees with respect to the water's surface, it will see

A) the bottom of the pond.
B) another fish in the pond.
C) the sky and possibly some hills.
D) only the water's surface.
E) none of these

Rainbows exist because light is

A) reflected.
B) refracted.
C) both of these
D) neither of these

A person standing waist-deep in a swimming pool appears to have short legs because of light

A) reflection.
B) absorption.
C) interference.
D) diffraction.
E) refraction.

Different colors of light travel at different speeds in a transparent medium. In a vacuum, different colors of light travel at

A) different speeds.
B) the same speed.
C) light travels at the same speed everywhere.

When white light goes from air into water, the color that refracts the most is

A) red.
B) orange.
C) green.
D) violet.
E) All refract the same amount.

The refraction of light in a diamond is greater for

A) long-wavelength light.
B) short-wavelength light.
C) Both refract the same.

A primary rainbow is brighter than a secondary rainbow because

A) sunlight reaching it is more intense.
B) there is one less reflection inside the water drops.
C) larger drops produce primary rainbows.
D) the secondary bow is a dim reflection of the primary rainbow.
E) none of these

Figure 28-F

The sun's elliptical shape at sunset can be adequately explained by

A) Fermat's principle.
B) the law of refraction.
C) both of these
D) none of these

Objects infinitely far away are focused by a converging lens

A) in front of the focal point.
B) at the focal point.
C) beyond the focal point.

If you wish to spear a fish with a regular spear, you should compensate for refraction between the air and water and throw your spear

A) directly at the sighted fish.
B) above the sighted fish.
C) below the sighted fish.

Figure 28-G

From what you know about the refraction of various wavelengths of visible light, would red light and blue light from the same source produce images at the same place?

A) Yes.
B) No. Blue light would make an image closer to the lens.
C) No. Red light would make an image closer to the lens.

If you wish to hit a red fish with a red laser beam, you should compensate for refraction between the air and water by aiming your laser

A) directly at the sighted fish.
B) above the sighted fish.
C) below the sighted fish.

If you wish to hit a blue fish with a red laser beam, you should compensate for refraction between the air and water by aiming your laser

A) directly at the sighted fish.
B) above the sighted fish.
C) below the sighted fish.

If you wish to send a beam of laser light to a space station that is just above the atmosphere near the horizon, you should aim your laser

A) above your line of sight.
B) below your line of sight.
C) along your line of sight.

A person who sees more clearly under water without eyeglasses or a face mask is

A) nearsighted.
B) farsighted.
C) neither

A mirage occurs for surfaces that are

A) horizontal.
B) vertical.
C) both of these

A mirage occurs for road surfaces that are

A) warm.
B) cold.
C) wet.
D) hard.
E) snowy.

When light is refracted, there is a change in its

A) frequency.
B) wavelength.
C) both of these
D) neither of these

The moon's redness during a lunar eclipse results from

A) only lower frequencies being reflected from the moon.
B) infrared radiation that is normally blocked.
C) an optical illusion.
D) refraction by the Earth's atmosphere of Earth's sunrises and sunsets.
E) none of these

When a pulse of white light is incident on a piece of glass, strictly speaking, the first color to emerge is

A) red.
B) orange.
C) green.
D) violet.
E) They all emerge at the same time.

Magnification from a lens would be greater if light

A) propagated instantaneously.
B) traveled faster in glass than it does.
C) traveled slower in glass than it does.
D) beams spread out more.
E) none of these

When taking a picture of a nearby object, your camera lens should be moved

A) closer than one focal length from the film.
B) farther than one focal length from the film.
C) to one focal length from the film.

Ninety percent of light incident on a certain piece of glass passes through it. How much light passes through two pieces of this glass?

A) 80%
B) 81%
C) 85%
D) 89%
E) 90%

As monochromatic light passes from air to glass and back to air, changes are observed in its

A) wavelength, frequency, and speed.
B) wavelength and frequency.
C) wavelength and speed.
D) frequency and speed.
E) None of the above choices are correct.

If the speed of light in a medium is 2 × 108 m/s, the medium's index of refraction is

A) 0.50.
B) 0.67.
C) 1.0.
D) 1.5.
E) 2.0.

According to Huygens' principle, every point on a wave

A) is a diffraction source.
B) behaves as a source of new waves.
C) is the superposition of every other part of the wave.
D) all of these
E) none of these

Consider plane waves incident upon a barrier with a small opening. After passing through the opening, the waves

A) continue as plane waves.
B) fan out.
C) converge.
D) become polarized.
E) all of these

Diffraction is more pronounced through relatively

A) small openings.
B) large openings.
C) same for each

Waves diffract the most when their wavelength is

A) short.
B) long.
C) Both diffract the same.

The type of radio waves that is diffracted the most around small buildings are

A) AM.
B) FM.
C) Both diffract equally.

To perceive greater detail a dolphin emits sounds of

A) lower frequency.
B) higher frequency.
C) greater intensity.
D) greater speed.
E) none of these

For viewing tiny objects in a microscope, diffraction is

A) helpful.
B) a hindrance.
C) not a factor.

For radio reception, diffraction is

A) helpful.
B) a hindrance.
C) not a factor.

Diffraction is a result of

A) refraction.
B) reflection.
C) interference.
D) polarization.
E) dispersion.

Newton's rings are a demonstration of

A) refraction.
B) reflection.
C) dispersion.
D) polarization.
E) interference.

Interference is a property of

A) light waves.
B) sound waves.
C) water waves.
D) all of these
E) none of these

Colors seen when gasoline forms a thin film on water are a demonstration of

A) refraction.
B) reflection.
C) dispersion.
D) polarization.
E) interference.

Iridescent colors seen in the pearly luster of an abalone shell are due to

A) refraction.
B) diffraction.
C) dispersion.
D) polarization.
E) interference.

Polarization is a property of

A) transverse waves.
B) longitudinal waves.
C) both
D) neither

The vibrational direction of the electron and the plane of polarization of the light it emits

A) are the same.
B) are at right angles to each other.
C) may or may not be at right angles to each other.
D) are independent of each other.

Some double-pane airplane windows darken when the inner pane is rotated. The panes are

A) thin films.
B) Polaroid filters.
C) optical fibers.

Light will not pass through a pair of Polaroids when their axes are

A) parallel.
B) perpendicular.
C) 45 degrees to each other.
D) two of these
E) all of these

The glare seen from water is largely

A) horizontally polarized.
B) vertically polarized.
C) unpolarized.

The polarization axes of ordinary sunglasses are

A) vertical.
B) horizontal.
C) at right angles to each other.

The polarization axes of glasses for 3-D viewing are

A) vertical.
B) horizontal.
C) at right angles to each other.

Viewing exact duplicates of slides in the left and right positions of a stereo projector produces

A) depth.
B) no depth.

The function of polarizing filters in viewing 3-D slides or movies is to provide each eye

A) the ability to see parallax.
B) a balanced intensity.
C) an independent left or right-hand view.
D) a stereoscopic view.
E) with light polarized at right angles to each other.

A property of non-cubic transparent crystals is that light travels through them

A) in mutually perpendicular directions.
B) without refracting.
C) and becomes polarized in the process.
D) at different speeds along different optic axes.
E) none of these

A property of non-cubic transparent crystals is that polarized light that travels through them
A) breaks up into two perpendicular planes.
B)
B) is depolarized.
C) is rotated.
D) slows in speed.
E) none of these

An inventor proposes to equip an office with a polarized source of background music and let those who prefer not to hear it wear polarizing earplugs. His idea is

A) a good one – giving people a choice.
B) too expensive.
C) too much bother.
D) nonsense – you can't polarize a sound wave.

A hologram is simply a

A) complex diffraction grating.
B) thin sheet of non-cubic transparent crystals.
C) pair of semi-crossed polarization filters.
D) thin photographic film with microscopic images over the entire surface.
E) none 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

Interference colors for light are analogous to

A) resonance for sound.
B) the sonic boom for sound.
C) partial tones for sound.
D) Fourier analysis for sound.
E) beats for sound.

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

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.

Monochromatic light is light of a single

A) wavelength.
B) frequency.
C) color.
D) all of these
E) none of these

Consider the interference colors seen in a film of gasoline on a wet street. The function of the water is to provide a

A) means of spreading the gasoline into a thin film.
B) means of slowing the rapid evaporation of gasoline.
C) chemical bond with the gasoline.
D) second reflecting surface.
E) all of these

A thin film appears blue when illuminated with white light. The color being cancelled by destructive interference is

A) red.
B) green.
C) white.
D) blue.
E) none of these

The spacing of Newton's rings will be greater with

A) red light.
B) blue light.
C) white light.

Which of the following is a property of light waves, but not of sound waves?

A) frequency
B) wavelength
C) amplitude
D) polarization
E) none of these

The amount of light from an incandescent lamp that is transmitted through an ideal Polaroid filter is half, and through a real Polaroid filter is

A) less than half.
B) more than half.
C) half.

An ideal Polaroid will transmit 50% of unpolarized light incident on it. How much light is transmitted by two ideal Polaroids that are oriented with their axes parallel to each other?

A) 0%
B) 50%
C) 100%
D) between 0% and 50%
E) between 50% and 100%

A painting looks less flat when viewed with

A) one eye.
B) both eyes.
C) Polaroid glasses.

Holograms employ the principle of

A) diffraction.
B) interference.
C) both of these
D) neither of these

Magnification can be accomplished with a hologram when viewed with light that has a

A) longer wavelength than the original light.
B) shorter wavelength than the original light.
C) Holograms cannot be magnified.

The spacings between double-slit interference fringes is increased if the slits are

A) closer together.
B) farther apart.
C) narrower.
D) wider.
E) none of these

Interference effects are less visible for thick films because the reflected waves

A) from the bottom surface are too dim.
B) become too dispersed.
C) all end up in phase with each other.
D) are too displaced to interfere.

Camera lenses coated with a layer of transparent material of the right thickness are almost completely non-reflective for light near the middle of the visible spectrum. They do, however, reflect a significant amount of

A) green.
B) red.
C) white.
D) violet.
E) red and violet.

Because of absorption, a Polaroid will actually transmit 40% of incident unpolarized light. Two such Polaroids with their axes aligned will transmit

A) 0%.
B) 40%.
C) 100%.
D) between 0% and 40%.
E) between 40% and 100%.

Light from a lit match comes from

A) electrons.
B) protons.
C) neutrons.
D) all of these

To say that energy levels in an atom are discrete is to say the energy levels are well defined and

A) separate from one another.
B) separated from one another by the same energy increments.
C) continuous.
D) private.

Electrons with the greater potential energies with respect to the atomic nucleus are

A) inner electrons.
B) outer electrons.
C) both the same, actually

An excited atom is an atom

A) that has excess vibration.
B) that has one or more displaced electrons.
C) with more protons than electrons.
D) that is frantic.

Light is emitted when an electron

A) is boosted to a higher energy level.
B) makes a transition to a lower energy level.
C) neither of these

An atom that absorbs a photon of a certain energy can then emit

A) only a photon of that energy.
B) a photon of any energy.
C) only a photon of the same or higher energy.
D) only a photon of the same or lower energy.

A throbbing pulse of electromagnetic radiation is called a

A) proton.
B) photon.
C) lightron.
D) sparktron.
E) notron.

The energy of a photon is related to

A) the energy given to the atom that emits it.
B) the energy level difference though which it falls.
C) its frequency.
D) all of these
E) none of these

The highest frequency light of those below is

A) red.
B) green.
C) blue.
D) violet.
E) all the same

Which color of light carries the most energy per photon?

A) red
B) green
C) blue
D) violet
E) all the same

Ultraviolet light is

A) more energetic than X-rays.
B) produced by crossed Polaroids.
C) electromagnetic energy.
D) present everywhere.
E) none of these

Compared to the energy of a photon of red light, the energy of a photon of blue light is

A) less.
B) more.
C) the same.

Atoms of neon in a glass tube can be excited

A) once per atom.
B) over and over again.

The variety of colors seen in a burning log comes from the variety of

A) multi-layered incandescent surfaces.
B) electron transitions in various atoms.
C) temperatures.
D) chemicals in the log.
E) absorbing gases between the log and the viewer.

Fluorescent minerals on display in museums are illuminated with

A) infrared light.
B) ultraviolet light.
C) often either or both
D) none of these

The greater proportion of energy immediately converted to heat rather than light occurs in

A) a fluorescent lamp.
B) an incandescent lamp.
C) both the same

Light from two closely spaced stars will not produce a steady interference pattern at the Earth's surface because of

A) incoherence.
B) the inherent instability of the atmosphere.
C) their different radial distances.
D) their non-point like natures.
E) Closely spaced stars do produce interference patterns.

A photographer wishes to use a safety light in the darkroom that will emit low-energy photons. The best visible color to use is

A) violet.
B) blue.
C) green.
D) actually any of these
E) none of these

Discrete spectral lines occur when excitation takes place in a

A) solid.
B) liquid.
C) gas.
D) superconductor.
E) all of these

Light frequency from an incandescent lamp depends on the

A) amount of electrical energy transformed.
B) rate of atomic and molecular vibrations.
C) voltage applied to the lamp.
D) electrical resistance of the lamp.
E) transparency of glass.

Isolated bells ring clear, while bells crammed in a box have a muffled ring. If the sound of isolated bells is analogous to light from a gas discharge tube, then sound from the box crammed with bells is analogous to light from

A) a laser.
B) a fluorescent lamp.
C) an incandescent lamp.
D) a phosphorescent source.
E) none of these

An atom that emits a certain frequency of light is

A) not likely to absorb that same frequency.
B) an absorber of the same frequency.

The dark lines in the sun's spectrum represent light that is

A) absorbed by the sun's atmosphere.
B) emitted by the sun.
C) not emitted by the sun.

Spectral lines take the shape of vertical lines because

A) the light is vertically polarized.
B) they are simply images of a vertical slit.
C) the energy levels in the atom are parallel to one another.
D) all of these
E) none of these

Helium was first discovered in the

A) laboratory.
B) upper atmosphere.
C) sun.
D) island of Helios, in Greece.
E) by-products of nuclear fusion.

Astronomers can tell whether a star is approaching or receding from Earth by

A) its temperature.
B) its change in temperature.
C) its absorption spectra.
D) the Doppler effect.
E) all of these

Atoms can be excited by

A) thermal agitation.
B) electron impact.
C) photon impact.
D) all of these
E) none of these

Compared to the energy put into a laser, the energy of the laser beam is

A) more.
B) less.
C) the same.

In the process of fluorescence, part of the input energy immediately

A) becomes internal energy and the rest lower-frequency light.
B) cascades to excite other atoms in the material.
C) is emitted as higher-frequency light and the rest lower- frequency light.
D) excites electrons to metastable states.
E) none of these

The white light emitted by a fluorescent lamp is provided by the

A) mercury vapor in the lamp.
B) phosphors on the inner surface of the lamp.
C) high temperature of the glowing gas.
D) filtering effect of the glass tubing.

The main visible difference between phosphorescent and fluorescent materials is

A) an afterglow.
B) a difference in brightness.
C) the greenish color of phosphorescence.

Light from a laser is

A) monochromatic.
B) in phase.
C) coherent.
D) all of these
E) none of these

The efficiency of classroom lasers is typically

A) about one percent.
B) about ten percent.
C) about twenty percent.
D) appreciably more than twenty percent.

The fact that the air you breathe doesn't give off much visible light indicates that most of the electrons of its atoms are

A) in the ground state.
B) excited to metastable states.
C) relatively cool.
D) electrically neutral.
E) relatively far apart.

Green light emitted by excited mercury vapor corresponds to a particular energy transition in the mercury atom. A more energetic transition might emit

A) red light.
B) blue light.
C) either red or blue light.
D) white light.

If the energy levels in the neon atom were not discrete, neon signs would glow

A) red.
B) white.
C) blue.

If light in a spectroscope were passed through a star-shaped opening instead of a thin slit, spectral lines would appear as

A) lines, but with poorer resolution.
B) stars.
C) blobs of no definite shape.

If light in a spectroscope passed through round holes instead of slits, spectral lines would appear
A) as thicker lines.

B) round.
C) dimmer.

The fact that iron absorption lines occur in the solar spectrum directly indicates that there is iron in the solar

A) atmosphere.
B) surface.
C) interior.

A certain object emits infrared waves. If it were to emit light waves instead, its temperature would have to be

A) higher.
B) lower.
C) the same, temperature doesn't make any difference.

Which of the following continually emits electromagnetic radiation?

A) insects
B) radio antennas
C) red-hot coals
D) all of these
E) none of these

Sometimes a flashlight filament glows red instead of white. This indicates a lowness of

A) current in the filament.
B) battery strength.
C) filament temperature.
D) all of these
E) none of these

The radiation curve for a "red hot" object peaks in the

A) infrared region.
B) green region.
C) ultraviolet region.

The radiation curve for a "blue hot" object peaks in the

A) infrared region.
B) red region.
C) yellow region.
D) ultraviolet region.
E) none of these

A paint pigment that absorbs red light and gives off blue light

A) is fluorescent.
B) is phosphorescent.
C) is used in lasers.
D) is polarized.
E) doesn't exist.

A paint pigment that absorbs blue light and gives off red light

A) is fluorescent.
B) is phosphorescent.
C) is used in lasers.
D) is fluorescent or phosphorescent.
E) doesn't exist.

The absorption of an infrared photon that excites an atom to emit a green photon

A) occurs in plants.
B) occurs in the process of phosphorescence.
C) violates the law of energy conservation.
D) all of these
E) none of these

The hottest star is the star that glows

A) red.
B) white.
C) blue.
D) cannot be determined by color alone

Comparing the light from a glowing tube of neon gas with light in the beam of a helium-neon laser, we find the greater number of spectral lines in light from the

A) neon gas tube.
B) laser beam.
C) both about the same

The red laser beam from a helium-neon laser corresponds to a spectral line of

A) helium.
B) neon.
C) both of these
D) neither of these

For absorption spectra to exist

A) the light source must be a gas.
B) partially absorbent material must exist between the light source and spectroscope.
C) the spectroscope must be equipped with an absorption cell.
D) all of these
E) none of these

Light from a phosphorescent source

A) takes longer to travel from the source to you.
B) normally has a shorter wavelength than the light that initially produced it.
C) is cooler than light from a fluorescent source.
D) all of these
E) none of these

Which light source is more energy-efficient?

A) a fluorescent lamp
B) an incandescent lamp
C) both about the same

The energy of a photon depends on its

A) speed.
B) frequency.
C) amplitude.
D) all of these
E) none of these

Some minerals glow when illuminated with ultraviolet light. This is because

A) ultraviolet photons kick atomic electrons in the mineral into higher energy states.
B) ultraviolet photons have such high energy.
C) of selective reflection.
D) of selective transmission.
E) none of these

Some light switches glow in the dark after the lights are turned off. This is because of

A) fluorescence.
B) resonance.
C) incandescence.
D) a time delay between excitation and de-excitation.
E) none of these

A watch dial that continues to glow after a week in the dark is almost certainly

A) fluorescent.
B) phosphorescent.
C) polarized.
D) radioactive.

The Doppler effect from the back-and-forth motion of atoms in a glowing discharge tube tends to make the spectral lines slightly

A) thicker.
B) thinner.
C) more numerous.
D) none of these

The spectral lines are more distinct when viewed in a mercury vapor lamp under

A) high pressure.
B) low pressure.
C) same for each

Under very high pressure, the spectrum of a mercury vapor lamp begins to look like that from

A) an incandescent source.
B) a laser.
C) an ultraviolet source.
D) a gas other than mercury.
E) a monochromatic source.

Materials can be heated until "red hot." If some material is heated until it is "green hot," then

A) it would liquefy immediately.
B) it would be hotter than "white hot."
C) its molecules would be vibrating at nearly identical rates.
D) it would be a strong absorber of red light.
E) energy conservation would be violated.

If the radiation curve for an incandescent object peaks in the green region, the object would appear

A) red.
B) yellow.
C) green.
D) blue.
E) white.

No laser can emit more energy than is put into it. Can a laser emit more power than is put into it?

A) No.
B) Yes, although not continuously.
C) It is too early in our technological development to answer this question with a reasonable degree of certainty.

As a solid is gradually heated, the first color to glow is

A) red.
B) yellow.
C) white.
D) blue.