Unit 20: Electricity
electrical insulator
A material through which charge cannot flow easily.
electric field
An electric field exerts forces on any charged object placed in the field.
electrical conductor
An electrical conductor is a material through which charge can flow easily.
voltage
Because it is measured in volts, potential difference is also called voltage.
direct current
Charge flows only in one direction in direct current.
series circuit
Charge has only one path through which it can flow
electric circuit
Complete path through which charge can flow.
Name five safety devices used with electric current.
Correct wiring, fuses, circuit breakers, insulation, and grounded plugs.
parallel circuit
Electric circuit that has two or more paths through which charges can flow
What is the difference between a series circuit and a parallel circuit?
If one element stops functioning in a series circuit none of the elements will work, one element does not stop parallel circuits from functioning if they stop.
fuse
Prevents current overload in a circuit
electric power
Rate at which electrical energy is converted to another form of energy
circuit breaker
Switch that opens when current in a circuit is too high
grounding
Transfer of excess charge through a conductor to earth
electric charge
a property that causes subatomic particles such as protons and electrons to attract or repel each other. There are two types of electric charge, positive and negative.
electric current
continuous flow of electric charge.
battery
is a device that converts chemical energy to electrical energy. Batteries, like other voltage sources, have terminals that can connect to wires in a circuit.
alternating current
is a flow of electric charge that regularly reverses its direction.
superconductor
is a material that has almost zero resistance when its cooled to low temperatures.
resistance
is opposition to the flow of charges in a material. The SI unit of resistance is the ohm.
potential difference
is the difference in electrical potential energy between two places in an electric field. Potential difference is measured in joules per coulomb, or volts.
static electricity
is the study of the behavior of electric charges, including how charge is transferred between objects.
Ohm´s law
mathematical relationship between voltage, current, and resistance
law of conservation of energy
the total charge in an isolated system is constant.
induction
transfer of charge without contact between materials.