Deck 29: Light Waves

Question 1

For radio reception in city buildings, diffraction is

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

Answer 1

helpful.

Question 2

Diffraction is most closely related to

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

Answer 2

interference.

Question 3

Plane waves incident upon a barrier that pass through a small opening

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

Answer 3

fan out.

Question 4

Interference is a property of

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

Question 5

Diffraction is least when illumination is with

A)red light.
B)blue light.
C)an electron beam
D)none of the above

Question 6

Radio waves that diffract more around small buildings are

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

Question 7

Waves diffract the most when their wavelength is

A)short.
B)long.
C)both of these
D)neither of these

Question 8

Secondary wavelets spread from a wave with

A)reduced speed.
B)an unchanging speed.
C)an increased speed.
D)none of the above

Question 9

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 the above
E)none of the above

Question 10

The fanning out of waves upon passing through an opening is more pronounced through

A)small openings.
B)large openings.
C)same for each
D)none of the above

Question 11

Huygens' principle applies mainly to

A)refraction of waves in a medium.
B)reflection of waves.
C)both of these
D)neither of these

Question 12

The device that spreads light into its component colors in a spectroscope is a

A)prism.
B)diffraction grating.
C)either of these
D)neither of these

Question 13

Superposition of waves can produce

A)reinforcement.
B)cancellation.
C)partial cancellation.
D)all the above

Question 14

Diffraction is evident when a wave passes

A)through a small opening.
B)the edge of an object.
C)both of these
D)neither of these

Question 15

What can exist in the same place at the same time?

A)two large boulders
B)two tiny boulders
C)two waves
D)all of the above
E)none of the above

Question 16

For viewing tiny objects in a microscope, diffraction is

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

Question 17

Diffraction from foghorns is best if the waves being diffracted are

A)long.
B)short.
C)either of these
D)neither of these

Question 18

The superposition of identical waves affects

A)amplitude.
B)wavelength.
C)speed.
D)all of the above
E)none of the above

Question 19

A dolphin perceives greater detail by emitting sounds of

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

Question 20

A razor blade nicely shows diffraction fringes when illuminated with

A)ultraviolet light.
B)monochromatic light.
C)sunlight.
D)all of the above
E)none of the above

Question 21

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

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

Question 22

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

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

Question 23

The production of interference colors requires

A)a reflecting surface.
B)at least two reflecting surfaces.
C)a medium with a relatively low index of refraction.
D)none of the above

Question 24

Newton's rings will be closer together if illuminated with

A)red light.
B)blue light.
C)white light.
D)none of the above

Question 25

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

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

Question 26

Light from two closely-spaced stars cannot produce a steady interference pattern due to

A)incoherence.
B)the inherent instability of the atmosphere.
C)their different radial distances.
D)their non-point like natures.
E)closely spaced stars not producing interference patterns.

Question 27

Colors seen when gasoline forms a thin film on water illustrate

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

Question 28

Consider the interference colors in a film of gasoline on a wet street. The water provides 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 the above

Question 29

Interference colors in a soap bubble is evidence that the soap film

A)has two reflecting surfaces.
B)is thin.
C)both of these
D)neither of these

Question 30

When you view color in a soap film with sunlight in back of you, a friend on the other side of the soap film likely sees

A)the same color.
B)a different color.
C)only your head.

Question 31

Monochromatic light is light of a single

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

Question 32

When waves from a pair of closely-spaced slits arrive in phase

A)a bright fringe is produced.
B)a dark fringe is produced.
C)both bright and dark fringes are produced.
D)none of the above

Question 33

Thomas Young's two-source interference patterns demonstrate the

A)particle nature of light.
B)wave nature of light.
C)both of these
D)neither of these

Question 34

When waves from a pair of closely-spaced slits arrive out of phase

A)a bright fringe is produced.
B)a dark fringe is produced.
C)both bright and dark fringes are produced.
D)none of the above

Question 35

In the double-slit experiment, fringes are more widely spaced when illumination is with monochromatic

A)low-frequency light.
B)high-frequency light.
C)polarized light.
D)none of the above

Question 36

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

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

Question 37

Successive bright fringes in an interference pattern result from

A)equal-length distances from the slits.
B)distance from the slits successively increasing one wavelength at a time.
C)destructive interference.
D)none of the above

Question 38

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)are out of phase with one another.
D)are too displaced to interfere.

Question 39

Newton's rings illustrate

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

Question 40

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 of these

Question 41

Polarization is a property of

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

Question 42

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%.

Question 43

Three-dimensional viewing normally involves

A)parallax.
B)two-eye vision.
C)an ability to see 'around' things.
D)all of the above
E)none of the above

Question 44

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

A)45 degrees to each other.
B)parallel.
C)perpendicular.
D)all of the above
E)none of the above

Question 45

Light emitted by the Sun is

A)polarized.
B)nonpolarized.
C)sometimes polarized.

Question 46

A pair of crossed Polaroids will transmit light

A)of sufficiently long wavelengths.
B)that itself is polarized.
C)if a third Polaroid at about 45 degrees is inserted between the two.

Question 47

Parallax is evident when you view objects

A)with one eye.
B)with both eyes.
C)with one or both eyes.
D)in a completely dark room.

Question 48

An inventor proposes to equip an office with a polarized source of background music and polarizing earplugs for non-listeners. His idea is

A)a good one that provides personal choice.
B)too expensive.
C)bothersome.
D)nonsense because sound cannot be polarized.

Question 49

The polarization axes of glasses for 3-D viewing are

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

Question 50

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

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

Question 51

Which of the following is a property of light waves and NOT of sound waves?

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

Question 52

Polaroid sunglasses reduce much glare by polarization axes that are

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

Question 53

For a pair of Polaroids with axes at 45 degrees to each other

A)light will not pass.
B)light that passes is dimmer than for a parallel orientation.
C)another Polaroid is necessary for any light to pass.

Question 54

The glare seen from water is largely

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

Question 55

A painting looks less flat when viewed with

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

Question 56

An ideal Polaroid will transmit 50% of incident sunlight. How much light will be 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%

Question 57

Light travels through non-cubic transparent crystals

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 the above

Question 58

Light will pass through a pair of Polaroids when their axes are

A)45 degrees to each other.
B)parallel.
C)either of these
D)neither of these

Question 59

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

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

Question 60

The vibrational direction of 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.

Question 61

Holograms employ the principle of

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

Question 62

Three-dimensional viewing was popular in the past with slide projectors. If the slides for left and right positions in the stereo projector are duplicates of each other

A)depth can be seen.
B)no depth can be seen.
C)only parallax can be seen.

Question 63

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)neither for holograms cannot be magnified.

Question 64

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-eye view.
D)a stereoscopic view.
E)with light polarized at right angles to each other.

Question 65

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 the above