physics FINALly chap 29-30
a
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.
a
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
d
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.
e
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
A painting looks less flat when viewed with A) one eye. B) both eyes. C) Polaroid glasses.
e
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
d
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
c
A property of non-cubic transparent crystals is that polarized light that travels through them A)breaks up into two perpendicular planes. B) is depolarized. C) is rotated. D) slows in speed. E) none of these
e
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
b
A throbbing pulse of electromagnetic radiation is called a A) proton. B) photon. C) lightron. D) sparktron. E) notron.
d
A watch dial that continues to glow after a week in the dark is almost certainly A) fluorescent. B) phosphorescent. C) polarized. D) radioactive.
b
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
d
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.
b
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.
b
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.
b
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%
d
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.
d
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
d
Atoms can be excited by A) thermal agitation. B) electron impact. C) photon impact. D) all of these E) none of these
b
Atoms of neon in a glass tube can be excited A) once per atom. B) over and over again.
e
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.
e
Colors seen when gasoline forms a thin film on water are a demonstration of A) refraction. B) reflection. C) dispersion. D) polarization. E) interference.
b
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.
b
Compared to the energy put into a laser, the energy of the laser beam is A) more. B) less. C) the same.
a
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
b
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
d
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
c
Diffraction is a result of A) refraction. B) reflection. C) interference. D) polarization. E) dispersion.
a
Diffraction is more pronounced through relatively A) small openings. B) large openings. C) same for each
c
Discrete spectral lines occur when excitation takes place in a A) solid. B) liquid. C) gas. D) superconductor. E) all of these
b
Electrons with the greater potential energies with respect to the atomic nucleus are A) inner electrons. B) outer electrons. C) both the same, actually
b
Fluorescent minerals on display in museums are illuminated with A) infrared light. B) ultraviolet light. C) often either or both D) none of these
b
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
a
For radio reception, diffraction is A) helpful. B) a hindrance. C) not a factor.
b
For viewing tiny objects in a microscope, diffraction is A) helpful. B) a hindrance. C) not a factor.
b
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.
c
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.
c
Holograms employ the principle of A) diffraction. B) interference. C) both of these D) neither of these
b
If light in a spectroscope passed through round holes instead of slits, spectral lines would appear A) as thicker lines. B) round. C) dimmer.
b
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.
b
If the energy levels in the neon atom were not discrete, neon signs would glow A) red. B) white. C) blue.
a
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
c
In the process of fluorescence, the input is high-frequency light and the output is A) higher-frequency light. B) equally high-frequency light. C) lower-frequency light.+
e
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.
c
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
d
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.
d
Interference is a property of A) light waves. B) sound waves. C) water waves. D) all of these E) none of these
e
Iridescent colors seen in the pearly luster of an abalone shell are due to A) refraction. B) diffraction. C) dispersion. D) polarization. E) interference.
c
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
b
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.
d
Light from a laser is A) monochromatic. B) in phase. C) coherent. D) all of these E) none of these
a
Light from a lit match comes from A) electrons. B) protons. C) neutrons. D) all of these
e
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
a
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
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.
c
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.
d
Monochromatic light is light of a single A) wavelength. B) frequency. C) color. D) all of these E) none of these
e
Newton's rings are a demonstration of A) refraction. B) reflection. C) dispersion. D) polarization. E) interference.
d
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
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
d
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
b
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
a
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
c
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
a
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.
a
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.
a
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.
b
The energy of a photon depends on its A) speed. B) frequency. C) amplitude. D) all of these E) none of these
d
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
a
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
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.
c
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.
b
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
d
The highest frequency light of those below is A) red. B) green. C) blue. D) violet. E) all the same
c
The hottest star is the star that glows A) red. B) white. C) blue. D) cannot be determined by color alone
a
The main visible difference between phosphorescent and fluorescent materials is A) an afterglow. B) a difference in brightness. C) the greenish color of phosphorescence.
d
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
The radiation curve for a "red hot" object peaks in the A) infrared region. B) green region. C) ultraviolet region.
b
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
a
The spacing of Newton's rings will be greater with A) red light. B) blue light. C) white light.
a
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
b
The spectral lines are more distinct when viewed in a mercury vapor lamp under A) high pressure. B) low pressure. C) same for each
a
The type of radio waves that is diffracted the most around small buildings are A) AM. B) FM. C) Both diffract equally.
a
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.
b
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.
b
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
a
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.
c
Ultraviolet light is A) more energetic than X-rays. B) produced by crossed Polaroids. C) electromagnetic energy. D) present everywhere. E) none of these
a
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.
b
Viewing exact duplicates of slides in the left and right positions of a stereo projector produces A) depth. B) no depth.
b
Waves diffract the most when their wavelength is A) short. B) long. C) Both diffract the same.
b
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
b
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.
d
Which color of light carries the most energy per photon? A) red B) green C) blue D) violet E) all the same
a
Which light source is more energy-efficient? A) a fluorescent lamp B) an incandescent lamp C) both about the same
d
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
d
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
d
ecause 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%.
b
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
b
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.