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.