question

radio waves

answer

A surface that is considered rough for infrared waves may be polished for

question

away from normal

answer

A beam of light emerges from water into air at an angle. The beam is bent

question

the red glass

answer

The average speed of light is greatest in

question

below the sighted ﬁsh

answer

If you wish to spear a ﬁsh with a regular spear, you should compensate for refraction between the air and water and throw your spear

question

separate from one another

answer

To say that energy levels in an atom are discrete is to say the energy levels are well deﬁned and

question

only a photon of the same or lower energy

answer

An atom that absorbs a photon of a certain energy can then emit

question

all of these

answer

Light from a laser is

question

in the ground state

answer

The fact that the air you breathe doesn't give oﬀ much visible light indicates that most of the electrons of its atoms are

question

frequency

answer

The energy of a photon depends on its

question

the particle nature of light

answer

The photoelectric eﬀect best demonstrates

question

the number of electrons ejected per second

answer

When a clean surface of potassium metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased, which of the following will also increase?

question

red

answer

An excited atom decays to its ground state and emits a photon of green light. If instead the atom decays to an intermediate state, then the light emitted could be

question

6

answer

A hypothetical atom has four distinct energy states. Assuming all transitions are possible, how many spectral lines can this atom produce?

question

ultraviolet light.

answer

Fluorescent brighteners (often called 'wave shifters') are added to laundry detergents to increase the amount of blue light emitted by aging, yellowed fabrics. Brighteners obtain the energy they need to emit this additional blue light from:

question

blue light has a higher frequency than red light

answer

Red light has a longer wavelength than blue light, so you know that, in empty space

question

a.the bulb will emit a redder-than-normal light and will waste more energy producing infrared radiation.

answer

A very-long-life incandescent light bulb insures that its filament will not sublime quickly by running the filament at a lower temperature than a normal bulb. Because of the low filament temperature

question

energy producing ultraviolet radiation

answer

the bulb will emit bluer-than-normal light and will waste more

question

normal bulb

answer

the bulb will save energy by drawing less power from the power line while still producing the same amount of useful light as a

question

than a normal bulb

answer

the bulb will help save energy by drawing the same amount of power from the power line while producing more useful light

question

Less bright and more red

answer

During the summer, 'brownouts' (AC line voltage < 120V) are experienced in some large cities when the electrical demand exceeds supply. During a brownout, the light emitted from an incandescent lamp would be

question

ultraviolet light

answer

Electromagnetic radiation includes infrared, visible, and ultraviolet light. Although light travels as a wave, it is absorbed as individual particles called photons, which carry an amount of energy that depends on the frequency of the light. Of the three types of light mentioned above, the type of light that carries that most energy per photon is:

question

a.travels the slowest in glass

answer

When white light is separated into its colors by a glass prism, blue light is bent at the greatest angle. This means that, of all the colors, blue light

question

their frequency.

answer

The thing that is different between x-rays and radio waves is

question

the speed at which they travel

answer

and the thing that is the same of x-rays and radio waves is

question

all of the time

answer

An ice cube in a dark room emits electromagnetic ("black- body") radiation:

question

an electron drops from a higher to a lower energy level

answer

Emission of light from an atom occurs when?

question

Bohr

answer

Who is given credit for the uncertaintity principle?

question

E = hv

answer

Which of the following is Planck's equation?

question

violet

answer

Which of the following light waves has the greatest energy?

question

the electron's main energy level

answer

What does the first quantum number (n) stand for?

question

an area where an electron has the greatest probability of being found

answer

What is an electron cloud ?

question

hc/E

answer

Which of the following can be used to calculate the wavelength of a band of light?

question

3.00 X 10-8th

answer

The speed of light in meters/sec. is

question

line spectrum

answer

Another name for atomic emission spectrum is

question

wavelength

answer

The frequency of a wave is inversely proportional to its

question

radio waves

answer

Microwaves have shorter wavelengths than

question

None of these

answer

Who proposed that light is emitted or absorbed by an object in fixed amounts called quanta?

question

the energy of photons

answer

Upon what does the photoelectric effect depend?

question

light

answer

What has properties of both particles and waves?

question

line spectrum

answer

What identifying feature of elements is produced when elements emit light?

question

energy of electrons is quantized

answer

Why do elements supposedly have unique line spectra?

question

Heisenburg's Uncertainty Principle

answer

When you measure the position of an electron, you invariably change the electron's momentum. This idea was stated in

question

phase

answer

A "wave front" is a surface of constant:

question

both I and II

answer

Consider (I) the law of reflection, and (II) the law of refraction. Huygens' principle can be used to derive:

question

light is a wave phenomenon

answer

Interference of light is evidence that:

question

to create a path length difference

answer

The reason there are two slits, rather than one, in a Young's experiment is:

question

a wavelength

answer

In a Young's double slit experiment, the center of a bright fringe occurs wherever waves from the slits differ in the distance they travel by a multiple of:

question

two wavelengths

answer

Waves from two slits are in phase at the slits and travel to a distant screen to produce the second side maximum of the interference pattern. The difference in the distance traveled by the waves is:

question

use a blue filter instead of a yellow filter

answer

Light from a small region of an ordinary incandescent bulb is passed through a yellow filter and then serves as the source for a Young's double slit experiment. Which of the following changes would cause the interference pattern to be more closely spaced?

question

a halving of the fringe spacing

answer

In a Young's double slit experiment, the slit separation is doubled. This results

question

halve the slit separation

answer

In an experiment to measure the wavelength of light using a double slit, it is found that the fringes are too close together to easily count them. To spread out the fringe pattern, one could:

question

no phase change

answer

Light in medium 1 of index of refraction n1 is reflected from an interface with medium 2 of index of refraction n2, where n1>n2. The reflected light gains:

question

a phase change of π

answer

Light in medium 1 of index of refraction n1 is reflected from an interface with medium 2 of index of refraction n2, where n1<n2. The reflected light gains:

question

λ/4

answer

Monochromatic light, at normal incidence, strikes a thin film in air. If λ denotes the wavelength in the film, what is the thinnest film in which the reflected light will be a maximum?

question

the dark bands spread out, disappearing off the left edge

answer

An air wedge is formed from two glass plates which are in contact at their left edges. There are ten dark bands when viewed by the reflection using monochromatic light. The left edge of the top plate is now slowly lifted until the plates are parallel. During this process:

question

their phase difference is constant

answer

If two light waves are coherent:

question

the light must be coherent

answer

To obtain an observable double-slit fringe pattern:

question

diffraction

answer

When a highly coherent beam of light is directed against a very fine wire, the shadow formed behind it is not just that of a single wire, but rather looks like the shadow of several parallel wires. The explanation of this involves:

question

refraction

answer

The rainbow seen after a rain shower is caused by:

question

the midpoint of the slit

answer

At the first minimum, adjacent to the central maximum of a single-slit diffraction pattern, the Huygens wavelet from the top of the slit is 180 degrees out of phase with the wavelet from:

question

a point one-fourth of the slit width from the top

answer

At the second minimum adjacent to the central maximum of a single-slit diffraction pattern, the Huygens wavelet from the top of the slit is 180 degrees out of phase with the wavelet from:

question

none of the above

answer

In a single-slit diffraction pattern, the central maximum is about twice as wide as the other maxima. This is because:

question

the width of the central diffraction peak increases and the number of bright fringes within the peak stays the same

answer

If we increase the wavelength of the light used to form a double-slit diffraction pattern:

question

the intensity at the center of the pattern does not change and the pattern expands away from the bright center

answer

A diffraction pattern is produced on a viewing screen by illuminating a long narrow slit with light of wavelength λ. If λ is increased and no other changes are made:

question

increasing the lens diameters

answer

The resolving power of a telescope can be increased by:

question

become narrower

answer

As more slits with the same spacing are added to a multiple-slit system, the lines:

question

crowds together

answer

A light spectrum is formed on a screen using a diffraction grating. The entire apparatus (source, grating, and screen) is now immersed in a liquid of index 1.33. As a result, the pattern on the screen:

question

even order lines of the 450nm light coincide with lines of the 900nm light

answer

A mixture of 450nm and 900nm light is incident on a multiple-slit system. Which of the following is true?

question

form the arc of a half circle

answer

At a diffraction line, phasors associated with waves from the slits of a multiple slit barrier:

question

the orders of the lines that are missing are all multiples of 4

answer

For a certain multiple-slit barrier, the slit separation is 4 times the slit width. For this system:

question

the lines narrow

answer

Two nearly equal wavelengths of light are incident on an N-slit grating. The two wavelengths are not resolvable. When N is increased they become resolvable. This is because:

question

the slit separation should be decreased

answer

To obtain greater dispersion by a multiple-slit system:

question

2

answer

The frequency of light beam A is twice that of light beam B. The ratio EA/EB of photon energies is:

question

greater for A than B

answer

Light beams A and B have the same intensity but the wavelength associated with beam A is longer than that associated with beam B. The photon flux (number crossing a unit area per unit time) is:

question

the number of photons that hit the sample

answer

In a photoelectric effect experiment at a frequency above cut off, the number of electrons ejected is proportional to:

question

none of the above

answer

In Compton scattering from stationary electrons, the frequency of the emitted light is independent of:

question

the photoelectric effect

answer

Which of the following is NOT evidence for the wave nature of matter?

question

the reflection of electrons by crystals

answer

Of the following, which is the best evidence for the wave nature of matter? A. the photoelectric effect

question

narrows

answer

Monoenergetic electrons are incident on a single slit barrier. If the energy of each incident electron is increased, the central maximum of the diffraction pattern:

question

has a longer wavelength and the same frequency

answer

A free electron and a free proton have the same kinetic energy. This means that, compared to the matter wave associated with the proton, the matter wave associated with the electron:

question

has the same wavelength and a greater frequency

answer

A free electron and a free proton have the same momentum. This means that, compared to the matter wave associated with the proton, the matter wave associated with the electron:

question

3, 2, 1

answer

Consider the following particles: 1. a free electron with kinetic energy K 2. a free proton with kinetic energy K 3. a free proton with kinetic energy 2K Rank them according to the wavelengths of their waves, least to greatest.

question

the square of the magnitude of its wave function

answer

The probability that a particle is in a given small region of space, is proportional to:

question

probability density

answer

The significance of |Ψ|2 is:

question

the wave function is made less narrow

answer

A free electron in motion along the x axis has a localized wave function. The uncertainty in its momentum is decreased if:

question

none of the above

answer

In order to tunnel through a potential barrier a particle must:

question

L decreases without any other changes

answer

An electron with energy E is incident on a potential energy barrier of height V and thickness L. The probability of tunneling increases if:

question

∫|ψ|2 dx = 1

answer

If a wave function , ψ, for a particle moving along the x axis is 'normalized', then:

question

n2

answer

The energy of a particle in a one-dimensional trap with zero potential energy in the interior and infinite potential energy at the walls is proportional to (n = quantum number):

question

2, 3, 1

answer

A particle is trapped in a one-dimensional well with infinite potential energy at the walls. Three possible pairs of energy levels are: 1. n=3 and n=1 2. n=3 and n=2 3. n=4 and n=3 Order these pairs according to the difference in energy, least to greatest:

question

2

answer

Two one-dimensional traps have infinite potential at their walls. Trap A has width L and trap B has width 2L. For which value of the quantum number n does a particle in trap B have the same energy as a particle in the ground state of trap A?

question

extends into the barriers

answer

An electron is trapped in a one-dimensional well with finite potential energy barriers at the walls. The matter wave:

question

3

answer

A particle is trapped in a finite potential energy well that is deep enough so that the electron can be in the state with n=4. For this state, how many nodes does the probability density have?

question

hydrogen atom?

answer

The quantum number n is most closely associated with what property of the electron in

question

13.6 eV

answer

The binding energy of an electron, in the ground state, in a hydrogen atom is about:

question

the circumference of each orbit is an integral multiple of electron wavelengths.

answer

The main reason electrons occupy discrete orbits in an atom is because

question

two thousand times the mass of an electron.

answer

The mass of an atomic nucleon is nearly

question

changes, but its mass number remains constant

answer

When a nucleus emits a beta particle, its atomic number

question

protons.

answer

The atomic number of an element is the same as the number of its

question

neutrons.

answer

Diﬀerent isotopes of an element have diﬀerent numbers of

question

86

answer

When radium (atomic number = 88) emits an alpha particle, the resulting nucleus has atomic number

question

alpha particle

answer

What experiences the greatest force in an electric field?

question

7.5 counts/min

answer

A certain radioactive isotope placed near a Geiger counter registers 120 counts per minute. If the half life of the isotope is one day, what will the count rate be at the end of four days?

question

frequency of 1000 Hz.

answer

1.If an electron vibrates up and down 1000 times each second, it generates an electromagnetic wave having a

question

green light

answer

The worst thing you can do for the health of a green-leafed plant is to illuminate it with only

question

perpendicular

answer

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

question

speed

answer

Refraction results from differences in light's

question

wavelength

answer

When light is refracted, there is a change in its

question

traveled slower in glass than it does.

answer

Magnification from a lens would be greater if light

question

the number of electrons ejected per second

answer

When a clean surface of potassium metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased, which of the following will also increase?

question

a)Only a photon of the same or lower energy.

answer

1.An atom that absorbs a photon of a certain energy can then emit

question

violet

answer

1.Which color of light carries the most energy per photon?

question

All of these

answer

The energy of a photon is related to

question

a)Maximum velocity of ejected electrons.

answer

1.In the photoelectric effect, the greater the frequency of the illuminating light, the greater the

question

a)Less kinetic energy than the absorbed photon's energy.

answer

1.In the photoelectric effect, electrons ejected from bound states in the photosensitive material have

question

The electron

answer

1.An electron and a baseball move at the same speed. Which has the longer wavelength?

question

A low-energy electron

answer

1.Which of the following has the longer wavelength?

question

Number of ejected electrons.

answer

1.In the photoelectric effect, the brighter the illuminating light on a photosensitive surface, the greater the

question

red

answer

1.An excited atom decays to its ground state and emits a photon of green light. If instead the atom decays to an intermediate state, then the light emitted could be

question

De Broglie wavelengths.

answer

1.In the Bohr model of hydrogen, discrete radii and energy states result when an electron circles the atom in an integral number of

question

De Broglie wavelengths.

answer

1.Orbital electrons do not spiral into the nucleus because of

question

a)Radioactive decay in the Earth's core.

answer

The source of the Earth's natural heat is

question

All of these

answer

1.The half-life of a radioactive substance is INDEPENDENT of

question

Outer electrons.

answer

1.Electrons with the greater potential energies with respect to the atomic nucleus are

question

In the ground state.

answer

1.The fact that the air you breathe doesn't give off much visible light indicates that most of the electrons of its atoms are

question

Planck's constant

answer

1.The ratio of a photon's energy to its frequency is

question

a)The circumference of each orbit is an integral multiple of electron wavelengths.

answer

1.The main reason electrons occupy discrete orbits in an atom is because

question

None of these

answer

1.When thorium (A = 90) emits a beta particle, the resulting nucleus has atomic number

question

a)Ultraviolet photons kick atomic electrons in the mineral into higher energy states.

answer

1.Some minerals glow when illuminated with ultraviolet light. This is because

question

a)The potential difference required to stop them.

answer

1.To study the energy of photoelectrons we measure

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