Physics
Electricity Study Guide
North Allegheny
Mr. Neff
Electrostatics
All electrons have the same amount of negative____________; all protons
have a ________________ charge equal in magnitude to the negative charge
of the electron.
Electrical forces arise because of the way like charges __________and
unlike charges _____________.
Electric charge is always -_________________. This means that there has
never been an observed occurrence of charge being ______________or
___________________.
According to ________________’s Law, the electrical force between two
charged objects is proportional to the product of the charges and inversely
proportional to the square of the ________________between them. Of the
three quantities (charge 1, charge 2, and separation distance),
____________________________________ is the most important because
of the square.
Electrons move ____________in good conductors and ____________in
good insulators.
Objects become ______________when electrons move onto or off of them.
______________do not move. So, a negatively charged object has an
____________of electrons, while a positively charged object has a
______________of electrons, not an excess of ______________, like a nonphysics type might think.
Electric Fields
An electric field fills the space around every ________________
____________. The field is strongest where it would exert the greatest
electrical _________on a small charge. The direction of a field at any point
is the direction of the electrical force on a ________________charge. An
electric field can be represented by electric field lines.
Static charge occupies only the __________surface of a conductor. Inside
the conductor the electric field is ________. This (rather than the rubber
tires) is why you are safe from __________________ inside a car.
An electric __________and some ____________inside that electric field
represent stored electric energy (electric potential energy). A charged object
has electric potential energy by virtue of its location in an electric field. The
electric potential, or ______________, at any point in an electric field is the
electric potential energy per unit of charge for a charged object at that point.
Electric Current
Electric ______________is the flow of electric charge that occurs when
there is a potential ____________________across the ends of an electric
conductor. The flow continues until both ends reach a common potential.
__________________and electric generators are voltage sources that
maintain a potential difference in a circuit. The amount of current that flows
in a circuit depends on the voltage and the electric
____________________that the conductor offers to the flow of charge. An
increased temperature or a longer wire increases resistance. A thicker wire
decreases resistance.
______’s law states that the amount of current is
________________proportional to the voltage and
__________________proportional to the resistance. Elegantly, Ohm’s law
is ________________. Resistors are used to control current.
Electric shock is the result of an electric current passing through the body
when there is a voltage difference between two parts of the body.
Electric fields travel through circuits at nearly the speed of light, but the
electrons themselves do not. In a DC circuit, electrons have a low
__________ speed within the wires. In AC circuits, energy, not electrons,
flows from the outlet. The electrons superimpose a rhythmic vibration on
rapid random motion.
Electric __________, the rate at which electric energy is converted into
other forms of energy, is equal to the product of current and voltage.
Elegantly, P = I V =V2 / R = I2 R.
Any path along which electric charge (usually electrons) can flow is a
______________. A compete circuit is needed to maintain a continuous
flow of charge.
Electric Circuits
A _____________ is a convenient way to produce a ______________
______________ by chemical means. Because of internal
_______________ , a battery does not perform in a circuit as one would
expect. Ideally, the voltage across the battery’s terminals would be equal to
the _______________________, but because of internal resistance, the
battery functions at a lower voltage, generally called the
_____________________.
In a ____________circuit, electrical devices form a ____________pathway
for electron flow. A break anywhere in the path stops the electron flow in
the entire circuit. The total resistance is equal to the _________of the
individual resistances along the current path. The current is equal to the
voltage divided by the total resistance. The voltage drop across each device
is proportional to its resistance. The sum of voltage drops across the
resistance of each individual device is equal to the total voltage.
In a ________________circuit, electrical devices form ________________,
each which provides a separate path for the flow of electrons. The
____________________of the equivalent resistance of the circuit is equal to
the sum of the reciprocals of the individual resistances. Each device
connects the same two points of the circuit; the voltage is the same across
each device. The amount of current in each branch is
__________________proportional to the resistance of that branch. The total
current is equal to the sum of the currents in each branch.
In a circuit with several resistors, the ____________________resistance is
the value of the single resistor that would comprise the same load to the
battery or power source. For resistors in series, the equivalent resistance is
the sum of their values. For resistors in parallel, the equivalent resistance is
less than the value of any individual resistor.
Answers
Charge
Positive
Repel
Attract
Conserved
Created
Destroyed
Coulomb’s
Distance
separation distance
easily
poorly
charged
Protons
Excess
Deficit
Protons
electric charge
force
positive
outer
zero
lightning
field
charge
voltage
current
difference
Batteries
Resistance
Ohm’s
Directly
Inversely
V = IR
Drift
Power
Circuit
Battery
Potential difference
Resistance
Electromotive Force
Terminal Voltage
Series
Single
Sum
Parallel
Branches
Reciprocal
Inversely
equivalent