Introduction to Alternating Current and Electrical Fundamentals

Vocabulary flashcards covering core electrical terminology, glossaries, and fundamental concepts from Chapter 1 on Alternating Current.

Alternating current

A current that varies, or "alternates," from one polarity to another, where current flows from negative to positive while the power source changes polarity in relation to time.

Ampere

The unit of electrical current flow, abbreviated as amp or $A$, which measures the movement of electrons as $1\,\text{coulomb}$ per second past a fixed point.

Conductor

A material that easily passes electrical current, with common examples including silver, copper, and aluminum.

Direct current

A current that flows in one direction only without relationship to time.

Electromotive force

The electrical pressure generated between two areas with different amounts of electrical charge, measured in volts and represented in formulas by the letter $E$.

Electron flow theory

The theory stating that electrical current flows from a negative charge to a positive charge.

Insulator

A material that does not allow electrical current to flow easily, with examples including rubber, plastic, and mica.

Ohm

The unit of electrical resistance, often represented by the Greek letter omega ($\Omega$).

Periodic table of elements

A tabular arrangement of elements according to their atomic numbers so that elements with similar properties are in the same column.

Piezoelectric

Electricity created by stress or pressure in a material, especially a crystalline material.

Reluctance

The opposition that materials present to the flow of magnetic lines of flux, represented by the Greek letter rel ($R$) and measured in ampere-turns per weber.

Semiconductor

A material that falls between conductors and insulators in terms of electrical conductivity.

Valence ring or shell

The outermost shell of electrons in an atom.

Volt

The unit of electromotive force that pushes electrons through a circuit, equal to the work done per coulomb of charge ($\text{volts} = \text{joules per coulomb}$), represented by $V$ or by $E$ in calculations.

Circular mils

A unit used to express the cross-sectional area of a wire in conductor resistance calculations.

American Wire Gauge (AWG)

A standardized system for specifying wire sizes, where an increasing gauge number corresponds to a smaller cross-sectional area.

Skin effect

An electrical phenomenon in alternating current circuits that influences how current distributes across a conductor's cross-sectional area.

Eddy currents

Induced circulating currents within a conductor that affect the total current flow through it.

Left-hand rule for generators

A rule used to determine the direction of induced voltage and the resulting polarity of a generator output.