in order for the electric force of a stationary electron to act on another stationary electron, they must
A be touching
B be in a vacuum
C be far apart
D meet no special requirements
as an electron moves near an object, changes in the electric forces of the electron at the object
A occur as soon as the electron moves from one position to another
B occur at some arbitrary time later
C occur at a time later corresponding to the time for light to travel the distance from the electron to the object
D do not occur
changes in an electric force are propagated
A at the speed of light
B instantaneously
C at the speed of sound
D too slowly for us to notice
the first step in the response of our eye to a light wave is
A sympathetic vibrations of electrons in the retina
B chemical reactions in the retina
C generation of an electric current in the optic nerve
D destruction of molecules or cells in the retina
a single oscillating electron can excite sympathetic oscillations, according to our simple picture, in
A only one other electron
B two electrons on opposite sides
C as many electrons as are present
D no electrons unless some other electron is also oscillating
the wave associated with light
A creates waves in the ether
B requires a media in which to travel
C is simply a graphical representation of an electric and magnetic disturbance
D none of these
in the oscillating electron model of light, light is
A an oscillating electron
B the changing amplitude of the electrons
C the changing force between the electrons
D the source of energy for both electrons
when an electron responds to light it
A travels from the source of the light
B is attracted toward the source of the light
C is ejected from an atom
D performs sympathetic oscillations
as an electron oscillates, the force it exerts on other electrons
A disappears
B stays constant
C gets weaker
D oscillates
the force between two electrons
A exists only when one is moving
B exists only when they are close together
C tends to attract them together
D always exists no matter how far apart they may be
light is
A a changing electric force
B sympathetically moving electrons
C oscillations of an invisible medium
D none of these
a light wave is transmitted
A by colliding with a series of electrons
B as a series of oscillating air molecules
C as a constant electric force
D as an oscillating electric force
a medium is not required for the passage of light because
A it travels with infinite speed
B it travels only very short distances between electrons
C the universe is closely packed with matter
D no object moves between the two oscillating electrons
a light wave can be emitted, in the simplest model, by
A any oscillating object
B a rapidly accelerating object
C any oscillating electrical charge
D any rapidly moving object
a light wave is a moving, or changing,
A electron
B frequency
C electric force
D all of these
an electron undergoes sympathetic oscillations in response to
A direct contact with another electron
B a changing electric force
C changes in the nucleus of the atom
D the decay of a light wave
which of the following is not a property of light
A it is a force
B it has mass
C its speed in a vacuum is constant
D it can cause a suntan?
a change in the electric field around an electron that moves suddenly is felt by a second electron some distance away
A instantly
B after some finite time
C never
D none of the above
which of the following wavelengths corresponds to a visible photon
A 50 a
B 500 a
C 5000 a
D 50000 a
the "signal" of an am radio station is transmitted as small changes in the
A speed of the wave
B frequency of the wave
C wavelength of the wave
D amplitude of the wave
in an am radio broadcast, the sound waves are represented by
A slight changes in the frequency of the radio waves
B slight changes in the speed of the radio waves
C slow changes in the amplitude of the radio waves
D radio waves carrying the sound waves
which visible color has the longest wavelength
A brown
B blue
C red
D green
the angstrom is
A a unit of length equal to 4*10**-9 inches
B a unit of length equal to 4*10**+9 inches
C a unit of frequency equal to 4*19**-9 hertz
D a unit of frequency equal to 4*10**9 hertz
the electric field associated with a collection of charges represents
A forces they exert on each other
B the forces they would exert on an external charge
C the motion of charges in the collection
D the black body curve for the charges
an electric field is
A a charged particle
B a mathematical way of describing the action of a charged particle on another charged particle
C a mathematical relationship between an electric charge and the acceleration of gravity
D a stationary light wave.
in the ideal sound wave, air molecules move
A in the direction away from the sound source only
B back and forth only
C up and down only
D both back and forth and in the direction away from the sound source
an electric field is associated with an electron
A always
B whenever it moves
C whenever it interacts with another charge
D never
an oscillating electromagnetic field is a
A photon
B light wave
C a form of energy transfer between electrons
D all of these.
the carrier of an fm radio station is
A the radio waves
B the electric oscillation of the "information" broadcast by the station
C the device that transmits the radio waves
D the wires that carry the signal to the transmitter
the longest wavelength visible to the eyes is about
A 1a
B 4000a
C 7000a
D 186,000a
an oscillating electron
A is surrounded by an oscillating electric field
B is surrounded by a stationary electric field
C slowly loses its electric charge
D emits sound waves
in a normal water-wave, water molecules move
A up and down only
B in the direction of the wave motion
C in completely random directions
D do not move at all.
which of the following types of radiation is usually produced in nuclear reactions
A gamma rays
B x-rays
C ultraviolet
D radio waves
in an ideal water wave a water molecule moves
A in the direction the wave is moving
B along a crest or trough of the waves only
C up and down only
D not at all
the shortest wavelength visible to the eye is about
A 4a
B 400a
C 4000a
D 40,000a
the electric field around a stationary charge is
A the boundary within which the electric force acts
B a mathematical way of describing what force would act on another charge
C a cloud of electromagnetic waves
D nonexistent until the charge moves
which of the following is not necessarily a property of laser light
A all the waves oscillate together
B only one color is present
C all the waves travel in the same direction
D it is super powerful
the electric field which surrounds an isolated electron describes
A the way it is moving
B the magnitude of its electric charge
C the force a test charge would feel if brought near
D the force the electron would feel if a test charge were brought near.
a rapidly moving electron is surrounded by
A no fields
B an electric field only
C an electric and magnetic field only
D an electric, magnetic and gravitational field only
the signal of an am radio station is usually of lower "quality" than a fm station because
A slight changes in the amplitude of a radio signal may occur as it passes through the air
B there is less celestial static at fm frequencies
C fm radio waves are more easily reflected off the upper layers of the atmosphere
D am stations are not allowed to be as powerful as fm stations
the electric field at a point due to an electric charge is a way of describing
A the motion of the charge
B the interaction of the charge with light
C orbit of the charge in an atom
D the effect of the charge on another charge brought to the point
the electric field of an electron is present
A only when other charges are nearby
B only when the electron oscillates
C only when no other charges are nearby
D always
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