Electricity Flashcards
A closed pathway that has different paths is called
A parallel circuit
A circuit that has only one path of current is called
A series current
What are the characteristics of of a series’s circuit
Current is the same in every resistor; current is equal to the battery
Sum of the voltage drops across the individual resistors = voltage rating of the battery
Total resistance of the resistors is =sum of the resistant values
describe electrical forces
are formed form particles in atoms: nucleus, electron and proton
What is a charge
the attracting and repelling forces
If an atom has electrons taken away it has a ________ Charge
positive
If an atom has on electron removed, and has one more proton than electron, what is it’s charge?
positive
Coulombs law: the _________ varies directly as the product of the charges and inversely as the square of the ________
force
distance
What is the SI symbol for coulomb?
C
What are the basics of what makes a good conductor?
they allow electrons to move
electrons are “loose”
mostly metals
Describe what is going on with the atoms of insulators
they are tightly bound
electrons are bound - and they are poor conductors - they “hold” their electrons
resist flowing charges - ex glass, rubber
What are the three ways to electrically charge objects?
by friction
by contact - transference
induction - without physical contact
What does grounding do?
conducts a pathway to an infinite reservoir of electric charge
When something is electrically polarized, what can we say about the object?
there is an alignment of the charges, an electric dipole - not totally even, but a little more positive on one side and a little more negative on the other side
Why do electric have a vector quality?
they have a magnitude and direction
What is static electricity?
electric charge that has built up in once place
does not flow, but may jump from place to place
What are the three things that atoms are composed of?
protons
electrons
neutrons
The transfer of _______ between objects is the basis of electrostatics
electrons
If an object has extra electrons, it’s charge will be________ charge
negative
If an object has a loss of electrons it will have a ________ charge
positive
If an object has the same number of electrons and protons it is
neutral
What does the law of conservation state?
that electrons are neither created or destroyed, but transferred from one object to another
Opposite charges ___________
Negative charges __________
attract
repel
describe how you charge an object by the use of friction
rub materials together the a high affinity for electrons against something with a lesser affinity for electrons - they electrons will transfer to the first object making it negatively charged
How do you charge an object by contact or conduction?
touch to induce
requires a conductor not an insulator
How do you charge an object by induction?
no contact
electrons move as a result of the charge in the second object
What is a resistor?
reduces or varies the electric current - allows current to flow, but resists the flow
How much current ther is depends on not only the voltage, but also on the ___________
electrical resistance
electrons always move from a _______ charge to a __________ charge
positive
negative
Describe electric potential
energy per charge
how strong in Volts
Volts = joules/coulombs
What is a capacitor?
a charged capacitor discharges when a conducting path is provided between the plates
What is voltage?
it is an electric pressure that produces a current of flow of charge
What is DC?
one direction
direct current
Electricity flows from _________ charge to _________ charge
high
low
What is the charge of the electrons that flow?
negative
Charge will flow between points until the is no longer a _______________
potential difference
Describe electric current
the rate of flow of charge
What is something that provides a potential difference between 2 points that causes current to flow
Voltage source
batteries, generator
electric pump
What does electrical resistance depend on?
conductivity of the wire
thickness of the wire
length of the wire
temperature
____________ - explains the relationship between voltage, current and resistance
Volts = Amps * Resistance
Ohms Law
A simple circuit requires which three things?
load,
conductor
source
What does a diode do?
converts AC -> DC
acts as a one way valve
What does a capacitor do?
acts as a reservoir for changing AC -> DC
- smooths the electrical waves out
What is the equation to calculate power (watts)?
power = current * voltage W= Amps * V
Describe electric polarization
When the atoms line up with the negative and positive all in one direction
What is electric potential?
electric potential energy/charge
voltage = electric potential energy (j)/charge(C)
The SI unit for electric potential energy is the joule. what is the SI unit for electric potential?
Volt
What is electric current?
the flow of electric charge
What is an ampere?
An ampere is the flow of 1 coulomb of charge per second
As more and more resistors are added in parallel to a circuit, the equivalent resistance of the circuit _________ (increases/decreases?)
decreases
Electrical ________ arise because of the way like _______, opposite ________
forces
charges repel
charges attract
Give an example of charging by friction
charge rod contacts neutral object - charge will transfer
What is electrical resistance?
how hard it is for the electric chagre to flow
What is drift speed?
the speed at witch electrons travel through a conductor, 0.01 cm/s
Electric potential energy is measured in ________ we also call this potential ___________
Volts
Difference
