EE

Electricity

The flow of electrons in a circuit, a form of energy.

Static Electricity

Electrons that are moved from one place to another by rubbing or brushing.

Friction

Opposite nature of particles (+,-) in static electricity.

Non-friction

Same-kind particles (+,+ or -,-) in static electricity.

Current Electricity

The flow of electrons in a conductor, the flow of electric charge across an electrical field.

William Gilbert

Father of electricity, coined the word "electricity" based on the Greek word for amber.

Benjamin Franklin

Proved that lightning and the spark from amber were the same thing.

Luigi Galvani

Italian professor of medicine who discovered that the muscles of a frog contain electricity.

Alessandro Volta

Disagreed with Galvani and invented the first electric battery, the voltaic pile.

Michael Faraday

Credited for generating electric current on a practical scale through magnetism and motion.

James Watt

Inventor of the steam condensing engine, his name was given to the electric unit of power, the Watt.

Andre Marie Ampere

First to explain the electro-dynamic theory, his name is used for the unit of electric current (ampere).

George Ohm

Published "The Galvanic Circuit Investigated Mathematically" and his name is given to the unit of electrical resistance.

Frictional Energy (Static Electricity)

Produced by rubbing certain dissimilar materials together.

Pressure

Electricity produced from pressure is called piezoelectricity.

Heat

Electricity produced by the difference in temperature between two wires.

Chemical Reaction

Electric cells are electricity produced by chemical reactions.

Light

Produced by light striking photosensitive materials.

Magnetism

Produced by relative movement of a magnet and a wire.

Atoms

Smallest building blocks of matter, made up of protons, neutrons, and electrons.

Matter

Anything that occupies space and has weight, can be solid, liquid, gas, or plasma.

Elements

Substances that cannot be decomposed any further by chemical reaction.

Molecule

The smallest particle that a compound can be reduced to before breaking down to its elements.

Electron

Negatively charged particles that revolve around the nucleus of an atom.

Proton

Positively charged particles that stay in the nucleus of an atom.

Neutron

Particles having no charge, similar in size to protons but slightly greater in mass.

Nucleus

The central part of the atom where protons and neutrons are located.

Atomic Number

Represents the number of electrons or protons of an atom.

Atomic Mass

Represents the sum of protons and neutrons of an atom.

Valence Electron

Electrons found in the outermost shell or orbit of an atom.

Conductor

Material that allows electric charges to move through it, with free electrons as charge carriers.

Insulator

Material that resists the flow of electric charges, with no or very few free electrons.

SI Prefixes

Prefixes used in the International System of Units to denote powers of 10.

Direct Current System (DC)

A system of electric current that flows in one direction.

Direct Current (DC)

Electric current that flows in one direction and does not change in direction or amperage.

Electric Circuit Theory

The fundamental theory upon which all branches of electrical engineering are built.

Electric Circuit

An interconnection of electrical elements where each component is known as an element.

Open Circuit

A circuit where the two terminals are externally disconnected, resulting in zero current flow.

Short Circuit

A circuit where the two terminals are externally connected with zero resistance, resulting in zero voltage difference.

Closed Circuit

A circuit that forms a complete, closed path with good continuity throughout.

Ammeter

An instrument used to measure current, connected in series with the circuit.

Voltmeter

An instrument used to measure electric potential difference, connected in parallel with the part of the circuit.

Wattmeter

An instrument used to measure power in an electrical circuit.

Ohmmeter

An instrument used to measure resistance.

Multimeter

A universal instrument that can measure voltage, current, and resistance.

Electric Charge

An electrical property of atomic particles, measured in Coulombs (C).

Direct Current (DC)

Current that remains constant with time.

Alternating Current (AC)

Current that varies sinusoidally with time.

Chemical Effect

The effect of electric current on primary and secondary cells, and electroplating.

Voltage

The potential difference between two points in an electric circuit.

Power

The time rate of expending or absorbing energy, measured in watts (W).

Circuit Elements

Active and passive elements in an electric circuit.

Resistor

A circuit element used to impede the flow of current.

Inductor

A passive element designed to store energy in its magnetic field.

Capacitor

A passive element designed to store energy in its electric field.

Resistor Color Code

A color band system used to indicate the resistance value of a resistor.

Tolerance

The allowable difference between the actual and color-coded resistance value of a resistor.

Inductance

The property of an inductor to oppose changes in current flow.

Capacitance

The property of a capacitor to store electric energy.

Fixed Value Inductor

An inductor with a fixed amount of inductance.

Variable Inductor

An inductor with a variable amount of inductance.

Fixed Value Capacitor

A capacitor with a fixed amount of capacitance.

Variable Capacitor

A capacitor with a variable amount of capacitance.

Variable Capacitor

A type of capacitor in which the value of capacitance can be changed.

Capacitance

The ratio of the charge on one plate of a capacitor to the voltage difference between the two plates, measured in farads (F).

Ohm's Law

The current flowing in an electric circuit is directly proportional to the impressed emf applied to the circuit and inversely proportional to the equivalent resistance of the circuit.

Conductance

A measure of a material's ability to conduct electric current, measured in mho (U) or siemens (S).

Conductivity

The reciprocal of resistivity.

Series Network

Components are connected "end-to-end" in a circuit, with the current being equal in all parts of the circuit.

Voltage or Potential Divider

A circuit that produces a lower e.m.f. from a higher e.m.f., used in devices like potentiometers.

Parallel Network

Components are connected "across each other" in a circuit, with the voltage being equal in all parts of the circuit.

Current Divider

A method to find a specific current in a parallel network by substituting current and resistance values.

Battery and Cell

Devices that convert chemical energy into electricity, with batteries being rechargeable and cells being simple units.

Corrosion

The gradual destruction of a metal in a damp atmosphere due to simple cell action.

Network Theorem

An interconnection of elements or devices in a circuit.

Inductor

A passive element designed to store energy in its magnetic field.

Capacitor

A passive element designed to store energy in its electric field.

Complex Number and Phasor

Mathematical tools used in electrical engineering to represent resistances, currents, and voltages in circuits.

Rectangular form

A way of representing complex numbers that is best for adding and subtracting.

Polar form

A way of representing complex numbers that is often better for multiplying and dividing.

Sinusoidal Voltage and Current

A type of alternating current (AC) that reverses at regular time intervals and has alternately positive and negative values.

AC circuits

Circuits driven by sinusoidal current or voltage.

Sinusoidal signal

A signal that has the form of a sine or cosine function.

Alternating current

The current that constantly changes in amplitude and reverses direction at regular intervals.

AC Generation

The generation of alternating current in large power plants that are located where fuel and water are abundant.

Frequency

The number of complete cycles a wave goes through in a fixed period of time, commonly measured in Hertz (Hz).

Period

The amount of time required to complete one cycle of a waveform, the reciprocal of frequency.

Wavelength

The length of one complete wave or cycle, measured in distance per cycle.

Waveforms

Representations of the variation of a voltage or current plotted against time.

Peak Value

The greatest value of either voltage or current that a waveform reaches during each half cycle.

Peak to Peak Value

The difference between the peak positive value and the peak negative value of a sine wave, equal to twice the maximum or peak value.

Instantaneous i(t)

The value of an alternating quantity at any instant.

Average value

The steady current that is transformed by an alternating current driving the same time, the arithmetical average of all the values of an alternating quantity over one cycle.

Effective Value (RMS)

The root mean square value of an alternating current, defined as the square root of the average of the squares of the given quantity taken over a complete period.

Crest Factor or Peak Factor

The ratio of the maximum value to the RMS value of a waveform.

Form Factor

The ratio of the RMS value to the average value of a waveform.

Phase

The fraction of the time period of an alternating current that has elapsed since the current passed through the zero position of reference.

Phase angle

The difference in degrees between the voltage waveform and the current waveform with the same periodic time.

Angular Frequency

The phasor relationship between two or more waveforms, represented in radians per second.

Leading

An alternating quantity that reaches its maximum or zero value earlier compared to another quantity.