Electrical Units 110

This class describes how electricity flows and explains the basic units used to measure electricity.

Class Details

Class Name:
Electrical Units 110
This class describes how electricity flows and explains the basic units used to measure electricity.
Number of Lessons:
Additional Language:
Related 2.0 Class:
Electrical Units 101

Class Outline

  • Objectives
  • What Is Electricity?
  • Parts of an Atom
  • Positive and Negative Charges
  • Atomic Numbers, Electrons, and Shells
  • Bonding
  • Movement of Electrons
  • Conductivity
  • Producing Electricity
  • Circuits
  • Electrical Theory
  • Coulombs
  • Amperage
  • Voltage
  • Resistance
  • Ohm’s Law
  • Wattage
  • Direct Current and Alternating Current
  • Advantages of AC Current
  • Summary


  • Describe the overall method by which power sources result in electricity.
  • Identify the particles in an atom.
  • Understand the relationship between positive and negative charges.
  • State the maximum number of electrons allowed in the valence shell of an atom.
  • Describe how atoms bond with one another.
  • Describe electron transfer.
  • Explain why conductors encourage electron transfer.
  • Name the most common way that electricity is produced.
  • Define circuit.
  • Explain the difference between electron theory and the conventional current theory of electricity.
  • Relate coulombs to water to describe electrical measurement.
  • Define amps.
  • Define voltage.
  • Define resistance.
  • List the three electrical variables that are governed by Ohm’s Law.
  • Define wattage.
  • Describe direct current.
  • Describe alternating current.
  • List advantages of alternating current.


  • CMfgT
  • MSSC Maintenance Awareness


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.
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.