Electrical Units
Vocabulary Term
Definition
adaptor
A device that converts alternating current to direct current.
alternating current
Current that regularly reverses the direction of its flow.
amperage
The strength of an electrical current measured in amps.
ampere
A unit of electrical measurement that describes both an amount of electricity and the
time it takes to travel a certain distance. One amp equals one coulomb per second.
atom
The smallest particle of an element that still retains its characteristics.
atomic number
The number of protons in the nucleus of an atom.
bond
An electrical force that links two or more atoms together.
bonding
The joining of two or more atoms through the sharing or exchange of electrons.
circuit
A controlled path for electricity. A circuit includes a source, path, load, and control.
conductor
A material that allows free movement of electrons and therefore allows easy flow of
electricity. Most conductors are metals.
control
A component in a circuit that controls the flow of electricity.
conventional current theory
The belief that electricity flows out from a positive source seeking a negative
conclusion.
coulomb
The smallest quantity measurement of electical current. A coulomb may be thought of
as a "drop" of electricity.
current
The flow of electricity. Current is measured in amps.
direct current
Current that travels in one direction. It does not reverse the direction of flow.
electricity
A form of energy created by the movement of electrons.
electron
A negatively charged particle that orbits the nucleus of an atom. Electrons are involved
in chemical bonding and electrical conductivity.
electron theory
The belief that electricity flows out from a negative source seeking a positive
conclusion.
element
One of more than 100 substances from which all matter is made. Carbon, hydrogen,
and oxygen are examples.
filament
A type of resistor that gives off heat and light. Filaments are used in light bulbs.
generator
A device that converts mechanical energy into electrical power.
hydroelectric power
Electricity produced by turbines that are turned by water flow.
insulator
A material that has little electrical conductivity and high resistance to electrical
charges. Most insulators are plastics and ceramics.
load
A component in a circuit that converts electricity into light, heat, or mechanical motion.
Examples of loads are a light bulb, appliance, or machine.
magnetic induction
The process in which a material becomes magnetized in a magnetic field. Magnetic
induction commonly takes place within metals.
magnetism
An attraction between materials having opposite electrical charges. Magnetism most
often occurs between metals.
Electrical Units
Vocabulary Term
Definition
metal
Any of several elements that are electrically and thermally conductive. Metals are often
described as shiny or lustrous in appearance.
negative
The charge held by an electron in the shell of an atom. A negative charge is symbolized
by a minus sign.
neutron
A neutrally charged particle within the nucleus of an atom.
nucleus
The central portion of an atom that holds the protons and neutrons. Electrons orbit
around the nucleus.
ohm
Unit of measurement for electrical resistance.
Ohms Law
The universal truth that it takes one volt to push one amp through one ohm.
path
A conductor that directs electricity in a circuit. The path is often copper wire.
positive
The charge held by a proton in the nucleus of an atom. A positive charge is symbolized
by a plus sign.
proton
A positively charged particle within the nucleus of an atom.
resistance
The opposition to current flow. Resistance is measured in ohms.
semiconductor
A material or element, such as silicon, that has more electrical conductivity than an
insulator, but less than a conductor. It restricts electrons but still allows them to flow.
shell
The hollow, ball-shaped area of orbit of an electron.
source
The device that provides electrical power to a circuit. The source is the origin of
electricity, such as a power plant.
turbine
A machine that uses the motion or energy of moving water or wind to produce
movement in paddles, buckets, or other devices arranged in a circle. This mechanical
motion is converted to electricity.
valence shell
The outermost orbit of electrons in an atom.
volt
A unit of measurement for electromagnetic force, or pressure.
voltage
A measure of electrical pressure or potential. Voltage is measured in volts.
wattage
The amount of electrical power required by a device to work properly. For example,
light bulbs express a required wattage.
Watts Law
The universal truth stating that one watt equals one amp times one volt.