alternating current

A current formed when electrons flow in one direction, followed by a flow in the opposite direction.

aluminum

A silvery white metal that is soft, light, and an effective conductor.

ampere

A unit of measurement that indicates the amount of current flowing in a circuit.

atom

The smallest distinguishable unit of a material that maintains that material's characteristics.

batteries

A device that converts chemical energy into electrical energy. Batteries produce direct current.

circuit

A completely enclosed path consisting of various devices that contains an electrical current.

commutator

A device used to convert an alternating current into a direct current.

conductor

A material that is very effective at conducting electricity. Metals are generally excellent conductors.

control

The device that affects or alters the flow of current in a circuit. The control can turn the circuit on or off, or it can perform more sophisticated tasks.

copper

A reddish metal that is very ductile, thermally and electrically conductive, and corrosive resistant. Copper is often used to make electrical wire.

current

The flow of electricity through a circuit. Current is measured in amperes (or amps).

cycle

The time it takes for current to flow, pause, reverse direction, and pause again in an alternating current.

direct current

A current formed when electrons flow in one continuous direction.

electricity

Energy in the form of a flow of electrons.

electron

The smallest part of the atom that revolves around the positively charged nucleus. Electrons have a negative charge, and they are the basic source of electricity.

generator

A machine with a rotating component that converts mechanical energy into electrical energy.

hertz

A unit of measurement indicating a single cycle in an alternating current.

horsepower

A unit of measurement that indicates the amount of electrical power in larger devices. Horsepower is used instead of watts to describe many electric motors.

insulator

A material that is highly resistant to the conduction of electricity. Ceramics and polymers are excellent insulators.

kilowatt

A unit of electrical power that equals 1,000 watts.

load

The device that converts electricity into another form of energy, such as heat, light, or motion. The load uses the current in a circuit to perform work.

milling machine

An industrial machine that uses a rotary cutter to remove material from a part supported on its worktable.

ohm

A unit of measurement that indicates the amount of resistance in a circuit.

Ohm's Law

The law describing the relationship between voltage, amperage, and resistance. Ohm's Law states that volts equals amperes multiplied by ohms.

parallel circuit

A circuit that contains multiple loads and multiple paths for the flow of current.

path

The part of a circuit that directs the flow of electricity from the source to the load. Copper wire is used as the path in most circuits.

power factor

A value used to calculate the correct wattage for a circuit with an alternating current.

proton

A particle with a positive charge that is located in the nucleus of an atom.

resistance

The opposition to the flow of current in an electrical circuit. Resistance is measured in ohms.

series circuit

A circuit that contains multiple loads but only one path for the flow of current.

seriesparallel circuit

A circuit that contains some loads connected in series and other loads connected to form multiple paths for electricity.

silver

A silvery white metal that has the highest electrical conductivity of all metals. Silver is also fairly expensive.

source

The device that supplies the current that flows throughout a circuit. Examples of sources include batteries and generators.

volt

A unit of measurement that indicates the amount of voltage in a circuit.

voltage

The electrical force or pressure that causes current to flow in a circuit. Voltage is measured in volts.

voltage drop

The amount of voltage that exists across two points of an electrical circuit.

watt

A unit of measurement that indicates the amount of electrical power in a circuit.
