Chapter 11 Light
11.1 Electromagnetic Spectrum
1) The source of electromagnetic waves is vibrating
A) electric charges.
B) atoms.
C) molecules.
D) energy fields.
Answer: A
2) The frequency of an electromagnetic wave and the frequency of the vibrating electrons that
produce it are
A) nearly the same.
B) the same.
C) quite different.
Answer: B
3) Which of the following occupies the smallest percentage of the electromagnetic spectrum?
A) radio waves
B) microwaves
C) visible light
D) gamma rays
Answer: C
4) Which of these has a higher frequency than visible light?
A) radio wave
B) microwave
C) infrared wave
D) ultraviolet wave
Answer: D
5) Which of these has the longest wavelength?
A) radio waves
B) microwaves
C) visible light
D) gamma rays
Answer: A
6) Electromagnetic waves consist of
A) compressions and rarefactions of electromagnetic pulses.
B) vibrating electric and magnetic fields.
C) particles of light energy.
D) high-frequency sound waves.
Answer: B
7) Electromagnetic waves can travel in
A) a vacuum.
B) water.
C) both
D) none of the above
Answer: C
8) Both sound and light can travel in
A) a vacuum.
B) water.
C) both
D) none of the above
Answer: B
9) 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
Answer: A
10) If an electric charge is rapidly shaken up and down,
A) sound is emitted.
B) light is emitted.
C) electron excitation occurs.
D) an electromagnetic wave is produced.
Answer: D
11) The main difference between a radio wave and a sound wave is
A) frequency.
B) wavelength.
C) energy.
D) amplitude.
E) basic nature.
Answer: E
12) A sound wave and a light wave have identical
A) speeds.
B) wavelengths.
C) frequencies.
D) all of the above
E) none of the above
Answer: E
13) Both a radio wave and light wave have identical
A) speeds.
B) wavelengths.
C) frequencies.
D) all of the above
E) none of the above
Answer: A
14) A wave with a high frequency has a relatively
A) short wavelength.
B) long wavelength.
C) both
D) none of the above
Answer: A
15) A wave with a long wavelength has a relatively
A) low frequency.
B) high frequency.
C) both
D) neither
Answer: A
16) Which has the shortest wavelength?
A) radio waves
B) infrared waves
C) X rays
D) ultraviolet waves
E) light waves
Answer: C
17) Relative to radio waves, the velocity of visible light waves in a vacuum is
A) less.
B) more.
C) the same.
Answer: C
18) Relative to ultraviolet waves, the wavelength of infrared waves is
A) shorter.
B) longer.
C) the same.
Answer: B
19) An electron vibrating to and fro 1000 times per second 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.
Answer: D
20) If a light signal and a radio signal were emitted simultaneously from the Moon, the first
signal to reach Earth would be
A) radio.
B) light.
C) both
D) neither
Answer: C
11.2 Transparent and Opaque Materials
1) Relative to its average speed in air, the average speed of a beam of light in glass is
A) more.
B) the same.
C) less.
Answer: C
2) The natural frequency of atoms in glass is in the
A) infrared region of the spectrum.
B) visible region of the spectrum.
C) ultraviolet region of the spectrum.
Answer: C
3) When ultraviolet light is incident upon glass, most atoms in the glass
A) resonate.
B) pass the light energy along practically undiminished.
C) freely absorb and reemit most of the ultraviolet light.
Answer: A
4) Visible light that shines on a pane of transparent glass
A) produces a chain of absorptions and re-emissions through the glass.
B) transforms to thermal energy.
C) is mostly reflected.
Answer: A
5) When visible light is incident upon transparent glass, most atoms in the glass
A) are forced into vibration.
B) resonate.
C) convert the light energy into thermal energy.
Answer: A
6) Ultraviolet light that shines on a pane of transparent glass
A) produces a chain of absorptions and re-emissions through the glass.
B) transforms to thermal energy.
C) is mostly reflected.
Answer: B
7) Consider light energy that is momentarily absorbed in glass and then reemitted. Relative to the
absorbed light, the frequency of the reemitted light is
A) less.
B) the same.
C) more.
Answer: B
8) Compared with the speed of light in a vacuum, the speed of light in the empty space between
molecules in glass is
A) more.
B) the same.
C) less.
Answer: B
9) 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 thermal energy in the skin.
D) are absorbed rather than reflected by the skin.
E) are the predominant waves emitted by the Sun.
Answer: C
10) Compared with the light wave that shines on glass, the emerging light is
A) identical though not the same light wave.
B) exactly the same light wave.
C) a mixture of being the same and different light waves.
Answer: A
11) Compared with the photons of light that shines on glass, the emerging photons are
A) the same.
B) different though identical.
C) a mixture of being the same and different.
Answer: B
12) Materials generally become warmer when light is
A) absorbed by them.
B) reflected by them.
C) transmitted by them.
D) all of the above
E) none of the above
Answer: A
13) Glass is transparent to light of wave frequencies that
A) match its natural frequencies.
B) are below its natural frequencies.
C) both
D) neither
Answer: B
14) Glass is opaque to light with wave frequencies that
A) match its natural frequencies.
B) are below its natural frequencies.
C) both
D) neither
Answer: A
15) Which becomes warmer in sunlight, sunglasses or clear reading glasses?
A) sunglasses.
B) reading glasses.
C) both
D) neither
Answer: A
16) Which will warm up quicker in sunlight?
A) a piece of colored glass
B) a piece of clear glass
C) both the same
Answer: A
17) 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
Answer: B
18) Clouds are semi-transparent to
A) ultraviolet light.
B) infrared light.
C) none of the above.
Answer: A
19) The reason that a surface appears darker when wet has to do with
A) the darkness of liquids.
B) conversion of light to lower frequencies.
C) absorption of light re-reflecting inside the wet region.
Answer: C
20) Describe a model for explaining how light is transmitted through glass.
Answer: According to the model of light presented in the textbook, when a photon is incident on
a glass surface, it is absorbed by a glass molecule or atom and forces it into vibration. This
vibration results in the emission of an indistinguishable photon, which travels to the next atom or
molecule to repeat the process. A cascading process of absorption and reemission occurs until
the glass molecule at the far surface absorbs and reemits an identical photon.
21) Why is ultraviolet light not transmitted by glass?
Answer: Ultraviolet light (UV) is in the range of frequencies that resonate with atoms and
molecules in the glass. At resonance, the amplitudes of vibration are very large and atoms and
molecules hold onto UV energy for millions of vibrations, during which time the energy is
passed to neighboring atoms by many collisions. The transmitted energy takes the form of
thermal energy instead of light. So glass is transparent to visible light, but not to UV.
22) If you walk at a constant pace across a room of known length, your walking speed is the
room length divided by the time to cross the room. Now suppose you repeat your walk but
briefly stop along the way to interact with people sitting along your path. What effect does this
have on your average speed across the room? How is this analogous to light passing through
glass? In what way is it not analogous?
Answer: When you walk across the room and pause to greet people along the way, you are like
light passing through glass, pausing along the way to interact with atoms. Your average speed
across the room is lower when interactions occur, much like the speed of light is less in glass
than in a vacuum. How this is different is that in the case of walking across the room, you begin
the walk and you end it. There is only one you. But in the case of light through glass, the photon
that first interacts with the glass is not the photon that emerges through the glass. There is a chain
of different but identical photons cascading through the glass.
11.3 Reflection
1) In the law of reflection, the incident ray, the reflected 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.
Answer: A
2) 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 the above
E) none of the above
Answer: B
3) The amount of light reflected from the front surface of common window glass is about
A) 4%.
B) 8%.
C) 40%.
D) 92%.
E) 96%.
Answer: A
4) When light reflects from a polished surface, there is a change in its
A) frequency.
B) wavelength.
C) speed.
D) all of the above
E) none of the above
Answer: E
5) The inversion of your image in a plane mirror is actually an inversion of
A) left and right.
B) up and down.
C) front and back.
D) all of the above
Answer: C
6) If you walk toward 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 the above
Answer: C
7) The shortest plane mirror in which you can see your entire image is
A) half your height.
B) 3/4 your height.
C) 1/3 your height.
D) equal to your height.
E) dependent on your distance from the mirror.
Answer: A
8) 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 the distance from the mirror.
Answer: B
9) 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.
Answer: C
10) 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 image is red.
C) both images are red.
D) both images are reddish yellow.
Answer: A
11) 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) either
Answer: B
12) Compared to the wavelength of incident light, diffuse reflection occurs when the size of
surface irregularities is
A) smaller.
B) larger.
C) about the same.
Answer: B
13) A rough surface for infrared waves may be polished for
A) radio waves.
B) light waves.
C) both
D) neither
Answer: A
14) 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.
B) of added condensation on the inner surface of the windshield.
C) the film of water on your windshield is an additional reflecting surface.
D) the film of water on the roadway makes the road less diffuse.
E) none of the above
Answer: D
15) A diver shines light up to the surface of a smooth pond at a 10 ° 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°.
B) 10°.
C) more than 10°.
Answer: B
16) 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 presently 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 the above
Answer: C
17) When a mirror with a fixed beam on it is rotated through a certain angle, the reflected beam
is rotated through an angle
A) equal to the angle of rotation.
B) twice as much.
C) four times as much.
D) none of the above
Answer: B
18) 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.
Answer: B
19) Ninety-five percent of light incident on a mirror is reflected. How much light is reflected
from three mirrors in succession?
A) 81%
B) 85%
C) 86%
D) 90%
E) 95%
Answer: C
20) A pair of plane mirrors are placed at right angles to each other. A coin placed close to the
mirrors has at most
A) 2 images.
B) 3 images.
C) 4 images.
D) more than 4 images.
Answer: B
11.4 Refraction
1) Light is incident upon a pane of window glass at a particular angle. The angle of emerging
light is
A) less.
B) the same.
C) more.
Answer: B
2) Light travels faster in
A) warm air.
B) cool air.
C) a vacuum.
Answer: C
3) Light travels faster in
A) thin air.
B) dense air.
C) same in each.
Answer: A
4) Atmospheric refraction makes the daylight hours
A) longer.
B) shorter.
C) neither
Answer: A
5) A mirage is a result of atmospheric
A) reflection.
B) refraction.
C) scattering.
D) dispersion.
E) aberrations.
Answer: B
6) The twinkling of stars is a result of atmospheric
A) reflection.
B) refraction.
C) scattering.
D) dispersion.
E) aberrations.
Answer: B
7) Refraction results from differences in light's
A) frequency.
B) incident angles.
C) speed.
D) all of the above
E) none of the above
Answer: C
8) Light refracts when traveling from air into glass due to changes in light's
A) intensity.
B) wavelength.
C) frequency.
D) velocity.
E) amplitude.
Answer: D
9) A beam of light emerges from water into air at an angle bent
A) towards the normal
B) away from the normal.
C) in a direction parallel to the normal.
D) in a direction perpendicular to the normal.
E) not at all.
Answer: B
10) When a light beam emerges from water into air, the average light speed
A) increases.
B) decreases.
C) remains the same.
Answer: A
11) Refraction causes the bottom of a swimming pool to appear
A) deeper.
B) more shallow.
C) neither
Answer: B
12) Because of refraction, a person standing waist deep in a swimming pool appears to have
A) shorter legs.
B) longer legs.
C) thinner legs.
D) none of the above
Answer: A
13) If you wish to spear a fish with a regular spear, you should compensate for refraction and
throw your spear
A) directly at the sighted fish.
B) above the sighted fish.
C) below the sighted fish.
Answer: C
14) If you wish to spear a red fish with a red laser beam, you should compensate for refraction
and aim your laser
A) directly at the sighted fish.
B) above the sighted fish.
C) below the sighted fish.
Answer: A
15) If you wish to spear a small blue fish with a red laser beam, you should compensate for
refraction and aim your laser
A) directly at the sighted fish.
B) above the sighted fish.
C) below the sighted fish.
Answer: C
16) If you wish to send a beam of laser light to a space station that is above the atmosphere near
the horizon, aim your laser
A) above your line of sight.
B) below your line of sight.
C) along your line of sight.
Answer: C
17) When light is refracted, there is a change in its
A) frequency.
B) wavelength.
C) both
D) neither
Answer: B
18) What accounts for the additional few minutes of sunlight we experience daily, before sunrise
and after sunset?
Answer: Atmospheric refraction adds to daylight time. When we see the Sun on the horizon, it is
already below it. Refraction makes it appear higher in the sky, and we have about 9 minutes of
additional sunlight per day because of atmospheric refraction.
11.5 Color
1) Which has the higher frequency?
A) red light.
B) green light.
C) blue light.
D) all the same
Answer: C
2) Different colors of light correspond to different light
A) velocities.
B) intensities.
C) polarities.
D) frequencies.
E) none of the above
Answer: D
3) The color of an opaque object is the same as the light that is
A) transmitted.
B) absorbed.
C) reflected.
D) all of the above
E) none of the above
Answer: C
4) What color light is transmitted by a piece of blue glass?
A) red
B) white
C) blue
D) yellow
E) orange
Answer: C
5) The brightest color emitted by the Sun is
A) red.
B) orange.
C) yellow-green.
D) green-blue.
E) violet.
Answer: C
6) The color humans are most sensitive to is
A) red.
B) orange.
C) yellow-green.
D) green-blue.
E) violet.
Answer: C
7) The solar radiation curve is a graph of
A) colors of sunlight versus their frequencies.
B) colors of sunlight versus their wavelengths.
C) the path of the Sun about Earth.
D) brightness versus frequency.
E) intensity versus distance from the Sun.
Answer: D
8) The three colors that comprise the image on a TV screen are
A) red, blue, and yellow.
B) red, blue, and green.
C) yellow, blue, and green.
D) magenta, cyan, and yellow.
E) red, green, and yellow.
Answer: B
9) Colors seen on TV result from color
A) addition.
B) subtraction.
C) either
D) neither
Answer: A
10) Colors seen on the cover of our physical science book result from color
A) addition.
B) subtraction.
C) either
D) neither
Answer: B
11) Complementary colors are two colors that
A) share the same color scheme.
B) are additive primary colors.
C) are subtractive primary colors.
D) produce white light when added.
Answer: D
12) The complementary color of blue is
A) red.
B) green.
C) yellow.
D) cyan.
E) magenta.
Answer: C
13) Magenta light is 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 the above
Answer: A
14) A mixture of blue and yellow tiny dots on a printed page appears
A) orange.
B) yellow.
C) magenta.
D) blue.
E) green.
Answer: E
15) The inks used in printing the full-color photos in this book 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 the above
Answer: D
16) Humans see best in the yellow-green region of the spectrum. So the efficiency of sodium
yellow-green lamps that illuminate highways is
A) higher.
B) lower.
C) not affected.
Answer: A
17) Which interacts more with sounds of relatively high frequencies?
A) large bells
B) small bells
C) both the same
Answer: B
18) Which interacts more with light of relatively high frequencies?
A) large particles
B) small particles
C) both the same
Answer: B
19) The sky is blue because air molecules in the sky act as tiny
A) mirrors that reflect only blue light.
B) resonators that scatter blue light.
C) sources of white light.
D) prisms.
E) none of the above
Answer: B
20) 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.
Answer: C
21) 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.
Answer: C
22) Red sunsets are due to light of lower frequencies that
A) is scattered from larger particles in the air.
B) is refracted from larger particles in the air.
C) is reflected by clouds and relatively large particles in the air.
D) survive being scattered in the air.
E) appear reddish orange to the eye.
Answer: D
23) An important feature of red sunsets is 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) absorption effects of the smaller particles in the air.
Answer: B
24) A variety of sunset colors is evidence for a variety of
A) elements in the Sun.
B) apparent atmospheric thicknesses.
C) atmospheric particle sizes.
D) atmospheric temperatures.
E) primary colors.
Answer: C
25) 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.
Answer: A
26) Consider the appearance of an American flag submerged deep in water. The white stars and
red stripes appear
A) cyan and red.
B) cyan and blue.
C) red and black.
D) cyan and black.
Answer: D
27) 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.
Answer: D
28) The part of the electromagnetic spectrum most absorbed by water is
A) infrared.
B) lower frequencies of visible light.
C) middle frequencies of visible light.
D) higher frequencies of visible light.
E) all of the above
Answer: A
29) A red crab crawling very deep in the water where sunlight is very dim appears
A) red.
B) orange.
C) cyan.
D) brown.
E) black.
Answer: E
30) An object having no real color may be
A) white.
B) gray.
C) black.
D) any of the above
Answer: D
31) 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 the above
Answer: D
32) A blue object will appear black when illuminated with
A) blue light.
B) cyan light.
C) yellow light.
D) light.
E) none of the above
Answer: C
33) The yellow clothes of a stage performer appear black when illuminated by light that is
A) magenta plus cyan.
B) blue.
C) both
D) neither
Answer: C
34) 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.
Answer: C
35) 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.
Answer: A
36) The fact that you can get sunburned while submerged in water is evidence that water
A) absorbs infrared light.
B) transmits infrared light.
C) absorbs ultraviolet light.
D) transmits ultraviolet light.
Answer: D
37) The fact that you can get sunburned while in the shade is evidence of
A) infrared scattering.
B) infrared absorption.
C) ultraviolet scattering.
D) ultraviolet absorption.
Answer: C
38) If molecules in the sky scattered red-orange light instead of blue light, sunsets would be
A) orange.
B) yellow.
C) green.
D) blue.
E) none of the above
Answer: D
39) 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 the above
Answer: A
40) Distant dark-colored hills appear blue due to the color of the
A) atmosphere between the observer and the dark hills.
B) selectively reflected light that reaches a distant observer.
C) reflected light that survives scattering.
D) sky that is reflected off the hills.
Answer: A
41) Distant snow-covered hills appear yellowish due to 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.
Answer: C
42) What are the three primary colors for light addition? What colors appear when light of only
two primary colors are shone on a white screen? How would the color purple be produced?
Answer: The three primary colors are red, green, and blue. When two primaries overlap, the
resulting color is the complementary color of the third primary color. When red and green
overlap, for example, the color produced is the complement of blue-which is yellow. We produce
purple by adding red and blue lights.
43) On a color TV screen, red, green, and blue spots of light produce a full spectrum of colors.
What spots are activated to produce yellow? Red? Magenta? White?
Answer: Yellow is produced by simultaneously activating red and green; red is activated by red
only; magenta by red and blue, and white by all three primaries.
44) Explain why the sky is blue.
Answer: Nitrogen and oxygen molecules in the atmosphere scatter light of high frequencies more
than light of low frequencies. When sunlight encounters the atmosphere, light is scattered by
molecules that make up the atmosphere. Violet and blue light are scattered the most by
atmospheric molecules, and because our range of vision better sees blue than violet, the sky
looks blue to us.
45) Why are clouds white?
Answer: Clouds are composed of a wide variety of particles. The smallest scatter blue, the
medium scatter green, and the larger particles scatter reds. Scattering by these particles produces
the white we associate with a cloud. When the particles increase in size and absorb rather than
scatter light, we have a dark rain cloud-and likely rain.
46) Why is the color of seawater greenish blue?
Answer: Water is a strong absorber of infrared radiation because its molecules resonate to the
frequencies of infrared light. But water also absorbs visible red light, but not so much. So water
is weak in reflecting red light (it can't absorb AND reflect the same light!). To say it weakly
reflects red light is to say it strongly reflects the complementary color of red, which is cyan
(greenish blue).
11.6 Dispersion
1) The average speed of light is greatest in
A) red glass.
B) orange glass.
C) green glass.
D) blue glass.
E) same in all
Answer: A
2) The colors dispersed by a prism are due to different light
A) speeds inside the prism.
B) directions inside the prism.
C) energies inside the prism.
D) none of the above
Answer: A
3) 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 arched shaped.
Answer: A
4) 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.
Answer: C
5) The secondary rainbow is dimmer than the primary rainbow because
A) its colors are inverted.
B) it is larger, and its energy spreads across 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.
Answer: E
6) 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 the above
Answer: B
7) Rainbows exist because light is
A) reflected.
B) refracted.
C) both
D) neither
Answer: C
8) 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) decreased speed.
Answer: B
9) 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.
Answer: D
10) When a pulse of white light is incident on a piece of glass, the first color to emerge is
A) red.
B) orange.
C) green.
D) violet.
E) all the same
Answer: A
11) 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%
Answer: B
11.7 Polarization
1) Polarization is a property of
A) transverse waves.
B) longitudinal waves.
C) both
D) neither
Answer: A
2) The direction of vibration for an 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.
Answer: A
3) Light will not pass through a pair of Polaroids when their axes are
A) parallel.
B) perpendicular.
C) 45° to each other.
D) all of the above
E) none of the above
Answer: B
4) The glare seen from water is largely
A) horizontally polarized.
B) vertically polarized.
C) nonpolarized.
Answer: A
5) The polarization axes of ordinary sunglasses are
A) vertical.
B) horizontal.
C) at right angles to each other.
Answer: A
6) 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.
Answer: A
7) An ideal Polaroid will transmit 50% of nonpolarized incident light. How much light is
transmitted by two ideal Polaroids oriented with their axes parallel to each other?
A) 0%
B) 50%
C) 100%
D) between 0% and 50%
E) between 50% and 100%
Answer: B
8) Because of absorption, a Polaroid will actually transmit about 40% of incident nonpolarized
light. Two Polaroids with their axes aligned will transmit
A) 0%.
B) 40%.
C) 100%.
D) between 0% and 40%.
E) between 40% and 100%.
Answer: D
9) What is a major difference in the effect of wearing polarizing sunglasses versus sunglasses
that simply cut down on intensity?
Answer: Much of the glare from surfaces is polarized in a plane matching that of the reflecting
surface. Glare from water, for example, is horizontally polarized. Glasses with vertical
polarization axes cut out this glare, whereas regular sunglasses don't discriminate between glare
and bright light.
Test Bank for Conceptual Physical Science
Paul Hewitt, John Suchocki, Leslie Hewitt
9780321752932, 9780134060491
