Deck 26: Properties of Light

Question 1

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.

Answer 1

frequency of 1000 Hz.

Question 2

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.

Answer 2

a magnetic field is created.

Question 3

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.

Answer 3

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

Question 4

Compared to ultraviolet waves,the wavelength of infrared waves is

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

Question 5

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.

Question 6

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.

Question 7

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.

Question 8

Which of these electromagnetic waves has the shortest wavelength?

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

Question 9

Most of the waves in the electromagnetic spectrum are

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

Question 10

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

Question 11

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.

Question 12

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

Question 13

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

Question 14

Sunburns are produced by

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

Question 15

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.

Question 16

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

Question 17

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.

Question 18

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.

Question 19

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

Question 20

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

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

Question 21

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.

Question 22

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

Question 23

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

Question 24

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.

Question 25

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

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

Question 26

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.

Question 27

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

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

Question 28

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.

Question 29

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

Question 30

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

Question 31

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.

Question 32

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.

Question 33

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

Question 34

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.

Question 35

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.

Question 36

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

Question 37

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.

Question 38

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

Question 39

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.

Question 40

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

Question 41

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

Question 42

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

Question 43

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.

Question 44

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

Question 45

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