Physical Science Chapter 6
The law that predicts the behavior of electrostatic forces acting through space
Coulomb's law.
An electric field describes the condition of space around
a charged particle.
To be operational, a complete electric circuit must contain a source of energy, a device that does work, and
a conductor from the source to the working device and another conductor back to the source
A current-carrying wire always has
a magnetic field with closed concentric field lines around the length of the wire.
A current-carrying wire has a magnetic field around it because
a moving charge produces a magnetic field of its own.
The operation of which of the following depends on the interaction between two magnetic fields?
all of the above
A lodestone is a natural magnet that attracts
all of the above.
In which of the following currents is there no electron movement from one end of a conducting wire to the other end?
alternation current
Which of the following units are measures of rates?
amp and watt
The rate at which an electric current flow through a circuit is measured in units of
amp.
The strength of a magnetic field around a current-carrying wire varies directly with the
amperage of the current.
An electromagnet uses
an electric current to produce an electric current.
The speaker in a stereo system works by the action of
an electromagnet pushing and pulling on a permanent magnet.
In an electric current, the electrons are moving
at a very slow rate.
A piece of iron can be magnetized or unmagnetized. This is explained by the idea that
atoms of iron are grouped into tiny magnetic domains that may orient themselves in a particular direction or in a random direction.
A transformer
changes the voltage of an alternation current.
You are using which description of a current if you consider a current to be positive charge that flow from the positive to the negative terminal of a battery?
conventional current
unit of electric charge is the
coulomb.
Which variable is inversely proportional to the resistance?
cross-sectional area of conductor
What type of electric current is produced by fuel cells and solar calls?
dc
A material that has elections that are free to move throughout the material is a (an)
electrical conductor.
Which of the following is most likely to acquire an electrostatic charge?
electrical nonconductor
When a loop of wire cuts across magnetic field lines or when magnetic field lines move across a loop of wire
electrons are pushed are toward one end of the loop.
Electromagnetic induction takes place because
electrons have their own magnetic field, which interacts with an externally applied magnetic field.
When an object acquires a negative charge, it actually
gains mass.
An example of an electrical insulator is
glass.
Earth's magnetic field
has undergone many reversals in polarity.
Reverse the direction of a current in a wire, and the magnetic field around the wire will
have a reverse north pole direction.
Electromagnetic induction occurs when a coil of wire cuts across magnetic field lines. Which one of the following increases the voltage produced?
increased strength of the magnetic field
A positive and a negative charge are initially 2 cm apart. What happens to the force on each as they are moved closer and closer together? The force
increases while moving.
Magnetism is produced by
moving charges.
The north pole of a suspended or floating bar magnet currently points directly toward Earth's
north magnetic pole.
The electrical resistance of a conductor is measured in units of
ohm.
In which type of circuit would you expect the same voltage with an increased current as more and more resistances are added to the circuit?
parallel circuit
If you multiply amps by volts, the answer will be in units of
power.
If you multiply volts by amps, the answer will be in units of
power.
A solar call
produces electricity directly.
Electric power companies step up the voltage of generated power for transmission across the country because higher voltage
reduces the current, which lowers the energy lost to resistance.
A parallel circuit has
separate pathways for the current to flow through.
In which type of circuit would you expect a reduction of the available voltage as more and more resistances are added to the circuit?
series circuit
Which of the following is not considered to have strong magnetic properties?
silver
An electric meter measure the
strength of a magnetic field.
A permanent magnet has magnetic properties because
the magnetic domains are aligned.
Electrostatic charge results from
transfer or redistribution of electrons.
The current in the secondary coil of a transformer is produced by a
varying magnetic field.
The electrical potential difference between two points in a circuit is measured in units of
volt.
According to Ohm's law, what must be greater to maintain the same current in a conductor with more resistance?
voltage
A step-up transformer steps up the
voltage.
Units of joules per second are a measure called
watt.
Earth's magnetic field is believed to originate
with electric currents that are somehow generated in Earth's core.
A kilowatt-hour is a unit of
work.
