ASVAB Electronics Information

Electricity

A form of energy that can travel invisibly through conductors and is carried by moving charged particles, especially electrons.

Electrons

Tiny negative charges that orbit the nucleus of an atom.

Conductor

A material that allows an easy flow of electrons (e.g., silver, copper, aluminum).

Insulator

A material that resists the flow of electrons (e.g., rubber, plastic, ceramic).

Circuit

A loop of conductors that takes electricity from its source to the load and back to the source.

Load

Anything in a circuit that uses power, such as a heater, light, or motor.

Direct Current (DC)

A steady flowing type of electricity produced by batteries and used in flashlights, boom boxes, and computers.

Electric Current

The amount of electrons flowing through a conducting material.

Electric Power

The amount of power consumed by an electrical device.

Voltage

Annotated as V; the electrical pressure or force that affects the rate at which electricity flows through a conductor.

Voltage Drop

How much electrical pressure is used in a part of the circuit.

Frequency

The number of complete alternations (cycles) that alternating current makes per second.

Resistance

The opposition of a material to the flow of electricity through it.

Amperes

Annotated as A; represents current strength.

Ohms

Annotated as Ώ; represents the measurement of resistance in a circuit.

Watts

Annotated as W; represents the measurement of power consumed by an electrical device.

Electricity and Magnetism

A close relationship between electricity and magnetism that explains electromagnets, transformers, motors, and generators.

Alternating Current (AC)

A type of current that changes direction many times per second, mainly used in home wiring for long-distance transmission.

Electromagnet

A magnet created by wrapping a conductor (wire) around an iron core and passing a current through it.

Transformer

Essentially two electromagnets placed next to each other that change the voltage and amperage of a current.

Step-Up Transformer

A transformer with more turns of wire on the output side, creating a stronger output voltage than input voltage.

Step-Down Transformer

A transformer that has fewer turns of wire on the output side, reducing the output voltage relative to the input voltage.

Motor

A device that changes electric energy into kinetic energy using stationary magnets and a spinning electromagnetic rotor.

Generator

A device that changes kinetic energy into electric energy.

Series Circuit

A circuit where all moving electrons pass through every part, including all loads and switches.

Parallel Circuit

A circuit where loads are placed between two supply wires so that all loads receive the same voltage.

Circuit Rule

Current is the same at all points in a series circuit; voltage is the same at all points in a parallel circuit.

Circuit Breaker Box

A device that breaks up building electrical load into multiple circuits and prevents excess current from flowing.

Typical Wiring

Building wiring consisting of three wires: Black (hot conductor), White (grounded/neutral conductor), and Bare (emergency ground route).

Semiconductor

A material (like silicon) that can act as an insulator or conductor depending on added chemicals called dopants.

Transistors

Devices that can switch, regulate, or amplify electrical current based on the presence of a smaller signal.

Diodes

Devices that allow electric current to flow in one direction only.

Ohm’s Law Formula

A = V / Ώ (Current = Voltage / Resistance)

Law of Electrical Power Formula

W = V x A (Watts = Voltage x Amperes)

Finding Resistance in a Series Circuit

Add the resistance values of each load together.

Finding Resistance in a Parallel Circuit

Add the inverses of the individual resistance values.