Deck 11: Light

Question 1

Which has the shortest wavelength?

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

Answer 1

C

Question 2

Which of these has the longest wavelength?

A)radio waves
B)microwaves
C)visible light
D)gamma rays

Answer 2

A

Question 3

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 3

B

Question 4

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

Question 5

Relative to ultraviolet waves, the wavelength of infrared waves is

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

Question 6

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

A)frequency.
B)wavelength.
C)energy.
D)amplitude.
E)basic nature.

Question 7

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.

Question 8

A wave with a long wavelength has a relatively

A)low frequency.
B)high frequency.
C)both
D)neither

Question 9

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

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

Question 10

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

Question 11

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.

Question 12

Both sound and light can travel in

A)a vacuum.
B)water.
C)both
D)none of the above

Question 13

The source of electromagnetic waves is vibrating

A)electric charges.
B)atoms.
C)molecules.
D)energy fields.

Question 14

Which of the following occupies the smallest percentage of the electromagnetic spectrum?

A)radio waves
B)microwaves
C)visible light
D)gamma rays

Question 15

A wave with a high frequency has a relatively

A)short wavelength.
B)long wavelength.
C)both
D)none of the above

Question 16

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

Question 17

Electromagnetic waves can travel in

A)a vacuum.
B)water.
C)both
D)none of the above

Question 18

Which of these has a higher frequency than visible light?

A)radio wave
B)microwave
C)infrared wave
D)ultraviolet wave

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

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.

Question 21

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.

Question 22

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.

Question 23

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.

Question 24

Which will warm up quicker in sunlight?

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

Question 25

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.

Question 26

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.

Question 27

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.

Question 28

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.

Question 29

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.

Question 30

Describe a model for explaining how light is transmitted through glass.

Question 31

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

Question 32

Glass is opaque to light with wave frequencies that

A)match its natural frequencies.
B)are below its natural frequencies.
C)both
D)neither

Question 33

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.

Question 34

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.

Question 35

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

Question 36

Clouds are semi-transparent to

A)ultraviolet light.
B)infrared light.
C)none of the above.

Question 37

Glass is transparent to light of wave frequencies that

A)match its natural frequencies.
B)are below its natural frequencies.
C)both
D)neither

Question 38

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.

Question 39

Which becomes warmer in sunlight, sunglasses or clear reading glasses?

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

Question 40

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.

Question 41

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°.

Question 42

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

Question 43

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%.

Question 44

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.

Question 45

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?

Question 46

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

Question 47

Why is ultraviolet light not transmitted by glass?

Question 48

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

Question 49

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.

Question 50

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

Question 51

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

Question 52

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.

Question 53

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.

Question 54

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.

Question 55

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.

Question 56

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

Question 57

A rough surface for infrared waves may be polished for

A)radio waves.
B)light waves.
C)both
D)neither

Question 58

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.

Question 59

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

Question 60

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

Question 61

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.

Question 62

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.

Question 63

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.

Question 64

When light is refracted, there is a change in its

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

Question 65

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.

Question 66

Light refracts when traveling from air into glass due to changes in light's

A)intensity.
B)wavelength.
C)frequency.
D)velocity.
E)amplitude.

Question 67

Light travels faster in

A)thin air.
B)dense air.
C)same in each.

Question 68

Refraction results from differences in light's

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

Question 69

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

Question 70

A mirage is a result of atmospheric

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

Question 71

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.

Question 72

Refraction causes the bottom of a swimming pool to appear

A)deeper.
B)more shallow.
C)neither

Question 73

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%

Question 74

Atmospheric refraction makes the daylight hours

A)longer.
B)shorter.
C)neither

Question 75

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.

Question 76

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

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

Question 77

What accounts for the additional few minutes of sunlight we experience daily, before sunrise and after sunset?

Question 78

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.

Question 79

The twinkling of stars is a result of atmospheric

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

Question 80

Light travels faster in

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