# Basic Electrical Theory

## Basic Electrical Theory Courses

Duration: 0.50 Hrs

Course Level: Fundamental
Languages: English

Do you know the difference between current and voltage? This course on basic electrical theory will equip you with the knowledge you need to handle various calculations involving electrical circuits, both AC (alternating current) and DC (direct current). You will learn how to calculate voltage and electrical power in a circuit using Ohm’s Law and Watt’s Law. In this interactive online course, we’ll discuss how to determine the electrical resistance for the wiring in a circuit and the size power unit that will be needed to drive a piece of equipment. Finally, you’ll learn the difference between single- and three-phase power.

#### Learning Objectives

By the end of this course, you will be able to:

• Define the terms voltage, current and resistance
• Identify Ohm’s law
• Solve for current flow given the voltage and resistance of a circuit
• Identify Watt’s law
• Define how to calculate power
• Explain the difference between single and three phase AC power

Duration: 0.50 Hrs

Course Level: Fundamental
Languages: English

An understanding of basic electrical theory and mathematics is valuable for all electrical work. In this interactive online course, you’ll learn critical principles of Electrical Theory, and the Mathematics involved in performing calculations to solve electrical circuit parameters, such as voltage, amperage, resistance and power. This course will introduce you to Ohm’s Law, Watt’s Law, Kirchoff’s Law, and Faraday’s Law.

#### Learning Objectives

By the end of this course, you will be able to:

• Recall the basic principles of electrical theory
• Given a formula, solve for kilowatts
• Select the proper symbolism in reference to Ohms and Watts law calculations
• Recall the basic principles of Ohm’s Law

Duration: 0.25 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

An electrical switch is any device used to interrupt the flow of electrons in a circuit. This course begins with an overview of switches, then describes several types of common switches, and ends with common switch contact designs.

#### Learning Objectives

By the end of this course, you will be able to:

• Describe the purpose of a switch
• Describe the difference between maintained and momentary switches
• List the two major categories of switch actuation
• Explain the term “normally open”
• Describe “poles” and “throws”
• Define a limit switch
• Describe a mercury switch
• Describe a relay

Duration: 0.25 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Electrical components are in many things we use on a daily basis, from lights, to computers, to electronic toothbrushes. Each of these devices includes one or more circuits. The basic components of a circuit are an energy source, a conducting material, and a load. In order for a circuit to be useful, it needs a method of control. This module will discuss circuits and how they can be controlled.

#### Learning Objectives

By the end of this course, you will be able to:

• List and describe the basic components of a circuit
• Differentiate between series and parallel circuits
• Explain the purpose of a switch
• Describe different types of switches

Duration: 0.25 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

This course covers the four parts of an electrical circuit, as well as the differences between common circuit types including series, parallel, and combination circuits. This course illustrates electrical power and how to calculate it. Finally, it discusses power rating and power conversion and efficiency.

Duration: 0.25 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Electricity is a form of energy, and when considering circuits, electricity is defined as a flow of electrons. The flow of electrons is called current. Current flow occurs under the influence of a charge difference that is called voltage. Resistance is the tendency of a component to hinder the flow of current. This course briefly reviews the aspects of atomic structures that allow the flow of electricity and then describes the relationship between current, voltage and resistance in an electrical circuit.

#### Learning Objectives

• Describe what makes up electricity
• Describe how electrical current is created
• Define voltage
• List different sources of voltage
• Describe electrical resistance
• Describe the meaning of Ohm’s Law
• Identify the difference between direct and alternating current

Duration: 0.50 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

A digital multimeter is a single instrument that is capable of measuring voltage, current, and resistance, so it is useful for troubleshooting electrical circuits and equipment. Voltage measurements can be made between any two arbitrary points in a circuit or relative to a single absolute ground point. Either method can be used to isolate component performance problems within a circuit. Current measurements with a multimeter require incorporating the meter into a circuit, so they are more difficult to make. Voltage and current measurements require that a circuit be energized. Resistance measurements require that the power be off and the tested component isolated from the rest of the circuit.

#### Learning Objectives

• List precautions to be taken when making electrical measurements
• Describe a digital multimeter
• List what quantities can be measured with a multimeter
• Explain two methods of measuring voltage
• Describe how voltage can be used to detect bad components in a circuit
• Describe how resistance can be used to detect bad components

Duration: 0.50 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

A diode is simply the main building block of semiconductors. It’s a small electronic device that limits current flow to one direction. This course covers types of diodes, how to identify diodes, transistor construction, types of transistors, and atomic theory of semiconductors.

#### Learning Objectives

• Definition of a diode, a transistor, and a PN junction
• Types of diodes
• Identifying diodes
• Transistor construction
• Types of transistors
• Atomic theory of semiconductors

Duration: 0.50 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

A digital multimeter is a single instrument that is capable of measuring voltage, current and resistance. A digital multimeter is an indispensable general-purpose tool for troubleshooting electrical problems. There are other dedicated test instruments, which in various ways, go beyond the capabilities of the multimeter. This module describes the typical features and usage of digital multimeters, as well as those of voltage detectors, clamp ammeters, megohmeters, digital thermometers and oscilloscopes.

#### Learning Objectives

• List precautions to be taken when making electrical measurements
• Describe a digital multimeter
• List what can be measured with a multimeter
• Describe how voltage, current and resistance are measured
• Describe the advantages of a voltage detector
• Describe a clamp ammeter
• Describe what is unique about a megohmmeter
• Describe how an oscilloscope can be used

Duration: 0.50 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

One of the greatest benefits of electricity is its ability to transfer energy from where it is generated to where it is needed. Electrical wires, cables and cords are used to accomplish the transfer. Electrical wiring consists of a conductive material such as copper surrounded by an insulating material such as thermoplastic. The primary dangers associated with the distribution of electric power are electrocution and the generation of heat. These hazards must be considered when laying out and connecting all types of wiring.

#### Learning Objectives

• Define electricity
• List the major dangers of electricity
• List the factors which affect the resistance of a wire
• Differentiate between the terms wire, cable, and cord
• Explain the AWG wire sizing system
• Describe the factors that go into selecting an insulation material
• Describe the purpose of a raceway
• Describe the correct and incorrect uses of flexible cords

Duration: 0.25 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Voltage applied to a conductor creates a magnetic field around that conductor. It is possible to reverse this process and for a magnetic field to generate a voltage in a conductor. For this to occur, there must be some relative motion between the conductor and the magnetic field. Electromagnetic induction takes place whenever a conductor moves through a magnetic field or when a magnetic field moves across a conductor. The voltage inducted in the conductor is called electromotive force. If the conductor is connected in a complete circuit, a current will flow. This module covers the definition of electromagnetic induction, voltage generators, the left hand rule, solenoids, relays, and transformers.

#### Learning Objectives

• Definition of electromagnetic induction
• Voltage generators
• Left hand rule
• Solenoids
• Relays
• Transformers

Duration: 0.25 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

All workplaces depend on high quality lighting. In addition to providing illumination of workspaces, good lighting also plays a role in enhancing employee satisfaction and performance, as well as providing general comfort and safety. It reduces the risk of eye strain and any of the physical symptoms that accompany it, including headaches or neck pain. In the industrial setting, lighting does all this, plus it provides clear visual indication of functions, and control of various processes. This module will describe different types of lights and their common uses.

#### Learning Objectives

• Identify ways of classifying light bulbs
• Identify main lighting components
• Differentiate between incandescent, fluorescent, HID, LED, and neon lights
• Understand the function of high voltage components

Duration: 0.25 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

A magnet is a material that attracts other metals. About 4,000 years ago, it was found that a stone called magnetite attracted pieces of iron. It was later found that a long piece of magnetite would align itself with the north and south poles of the earth. Experimentation showed that one end would always align with the North Pole and the other end with the South Pole. This module will discuss the principles of magnets, magnetic fields, and types of magnets.

#### Learning Objectives

• Principles of magnets
• Magnetic fields
• Magnetic units
• Types of magnets
• Magnetic conductors
• Electric coils

Duration: 0.25 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

When a relay is used to switch a large amount of electrical power through its contacts, it is designated by a special name: contactor or starter. This course covers contactors, incoming and auxiliary contacts, overload heaters, starter construction, starter operation, using heater elements in troubleshooting, and typical starter configurations.

Duration: 0.25 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Photoswitches, proximity sensors, and feedback devices are all used to detect objects or information. They are useful in industrial and manufacturing environments to sense product or personnel in the line of machinery or equipment. This module discusses the operation of the different types of each of these.

#### Learning Objectives

• Describe the purpose of a photoswitch and its general operating principles
• Differentiate between the five basic types of photoswitches (retroreflective, thru-beam, polarized, diffuse, and convergent beam)
• Match the three basic types of proximity sensors (inductive, capacitive, and ultrasonic) with their principles of operation
• Describe the purpose of a proximity sensor
• Explain the operation of three feedback devices (incremental encoders, absolute encoders, and Hall effect sensors)
• Describe the purpose of a feedback device

Duration: 2.00 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Alternating Current is a course designed to familiarize participants with how alternating current (AC) circuits work, and how voltage and current can change depending on the load, the source, and how the load and source are connected together. After completing this course, participants should be able to determine current and voltage values for an AC sine wave; explain how resistance, inductance, and capacitance affect AC circuits; explain how to calculate power in AC circuits and how to adjust power by correctly selecting and sizing circuit components; and describe the construction, operation, and use of various types of transformers.

#### Learning Objectives

• Explain why voltage rises and falls in an AC circuit.
• Determine the voltage values for any theta of an AC sine wave.
• Calculate the peak, effective, and root mean square (rms) voltage values for a given AC sine wave.
• Identify the phase relationships between two AC waveforms.
• Identify leading and lagging waveforms.
• Create a vector diagram describing the phase relationships between two AC waveforms.
• Describe the phase relationship between voltage and current in a resistive AC circuit.
• Calculate the voltage, current, resistance, and power in an AC resistive circuit.
• Describe the voltage and current transients that occur in an inductive AC circuit.
• Identify factors that can affect the inductive reactance in an AC circuit.
• Recognize a vector diagram for an AC inductive circuit.
• Calculate the inductive reactance in an AC circuit.
• Describe the voltage and current transients that occur in a capacitive AC circuit.
• Identify factors that can affect the capacitance of an AC circuit.
• Recognize a vector diagram for an AC capacitive circuit.
• Calculate the capacitive reactance in an AC circuit.
• Describe the voltage and current relationships in circuits that contain resistance, inductance, and capacitance.
• Create vector diagrams that describe the impedance of AC circuits that contain resistance, inductance, and capacitance.
• Calculate the impedance, voltage, and current through AC circuits that contain resistance, inductance, and capacitance.
• Describe the effect of resonant frequencies in series and parallel circuits.
• Describe how bandwidth is affected by resistance in series and parallel circuits.
• Describe the relationship between true power, apparent power, and reactive power in an AC circuit.
• Calculate the true power, apparent power, reactive power, and power factor of an AC circuit.
• Determine whether the power factor of a circuit is leading or lagging.

Duration: 2.00 Hrs

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Grounding is a course designed to familiarize participants with both system grounding and equipment grounding. After completing this course, participants should be able to describe different types of grounding, describe National Electrical Code® (NEC®) requirements associated with system grounding, and describe how to size and install grounding electrode conductors. They should also be able to describe NEC requirements associated with equipment grounding, describe how to size equipment grounding conductors and bonding jumpers, and explain how to make sure that a grounding system is effective.

#### Learning Objectives

• Explain what grounding is.
• Describe the different types of grounding.
• Describe the problems of short circuits and ground faults, which are commonly associated with grounding.
• Describe the parts of and the NEC® grounding requirements for various types of electrical systems.
• Describe NEC® requirements for grounding electrodes.
Describe how to size and install grounding electrode conductors.
• Describe NEC® requirements for grounding and bonding electrical equipment and enclosures.
• Describe how to size an equipment grounding conductor.
• Describe how to size the bonding jumpers for a variety of applications.
• Describe the importance of an effectively grounded system.
• Describe NEC® requirements for grounding in different types of systems.
• Describe what a ground resistance tester is.
• Describe how a ground resistance tester can be used to test for effective grounds.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English

Kirchhoff’s two laws reveal a unique relationship between current, voltage, and resistance in electrical circuits that is vital to performing and understanding electrical circuit analysis. This course introduces Kirchhoff’s voltage and current laws and explains how to use these laws to calculate the voltage and current of circuits.

#### Learning Objectives

• State Kirchhoff’s voltage law.
• Given a circuit, solve for voltage using Kirchhoff’s voltage law.
• State Kirchhoff’s current law.
• Given a circuit, solve for current using Kirchhoff’s current law.
• Given a complex circuit, solve for current and voltage using Kirchhoff’s voltage and current laws.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English

The components of an electrical or electronic circuit can be connected in many different ways. The two simplest of these are called series and parallel and occur very frequently. Components connected in parallel are connected so the same voltage is applied to each component. In this course, participants will learn about the fundamentals of parallel circuits as well as how to calculate current, voltage, and resistance in them.

#### Learning Objectives

• Define a parallel circuit.
• State the relationship between current and voltage in a parallel circuit.
• Calculate total resistance in a parallel circuit.
• Calculate total current in a parallel circuit.
• Calculate voltage drops across each resistor in a parallel circuit.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English

This course is designed to aid in the training process by introducing participants to the basic principles involved in using electrical test equipment. Anyone who uses test equipment should be capable of operating and maintaining that test equipment. This capability must be the result of formal training and demonstrated through on-the-job training. Completion of the training process allows a person to be “qualified.” A person who does not meet this requirement should work under the direct supervision of a qualified person.

#### Learning Objectives

After completing this course, you will be able to:

• Explain the operation and use of a voltage tester.
• Describe multimeter use.
• Explain the major steps involved in using a clamp-on ammeter.
• Describe the steps for the proper operation of a megohmmeter.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English
Capability: Audio, Video

This course introduces the fundamental principles of electrical theory as applied to electrical circuits and devices such as transformers, inductors, and capacitors. The general topics covered in this course include the nature of electricity, basic electrical quantities and their units of measurement, electrical circuits, and electromagnetism.

#### Learning Objectives

After completing this course, you will be able to:

• Define the following terms: electricity, conductor, insulator, direct current (DC), and alternating current (AC).
• State the meaning of the following electrical terms, including their units of measurement: current, resistance, voltage, energy, and power.
• Explain how Ohm’s law relates to current, voltage, and resistance.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Running cables and conductors is an integral part of electrical maintenance. The topics covered in this course include how cables and conductors are classified, the factors that must be considered in selecting a conductor or cable for a particular application, and procedures for installing, splicing and terminating cables and conductors used in low-voltage applications.

#### Learning Objectives

After completing this course, you will be able to:

• Define conductors and how they are constructed.
• Discuss how wire size and insulation type determine how conductors and cables are classified.
• Explain how ampacity and insulation voltage capacity determine conductor ratings.
• Identify factors to consider when selecting a conductor.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English
Capability: Audio, Video

The fundamental relationships between current voltage and resistance in direct current (DC) circuits are basic to understanding all types of electricity and electrical circuitry. This course is intended as a general review of basic electrical concepts and circuit analysis for participants already possessing some background in electrical theory.

#### Learning Objectives

After completing this course, you will be able to:

• Name the electrical quantities represented by l, E, and R.
• State Ohm’s Law in words and as a formula.
• Calculate the current, voltage, or resistance of a simple circuit when any two of the quantities are known.
• Calculate the total resistance of a series circuit when its individual series resistances are known.
• Calculate the resistance of a single series component when the total circuit resistance and the remaining series resistances are known.
• State Kirchhoff’s Voltage Law.
• Calculate the voltage drops across each component in a series circuit.
• Calculate the current through a series circuit when a single resistance and its voltage drop are known.
• State Kirchhoff’s Current Law.
• Calculate the branch currents in a parallel circuit when the source voltage and the individual branch resistances are known.
• Calculate the total current through a parallel circuit when the individual branch currents are known.
• Calculate the total resistance of a parallel circuit when the individual branch resistances are known.
• Calculate the total resistance of a series-parallel circuit.
• Calculate the voltage drops in a series-parallel circuit.
• Calculate the branch currents in a series-parallel circuit.
• Calculate the voltage drop across a series component by the proportional voltage drop method.
• Calculate the branch current through a parallel branch by the proportional branch current method.
• Calculate the total resistance of any two parallel branches by the product over-sum method.
• Calculate the resistance of a circuit with any number of equal parallel resistances by using the R/n formula.
• Calculate the branch currents of a circuit with any number of equal parallel resistances by using the It/n formula.
• Given the source voltage and resistance of a circuit, calculate the additional series resistance required to limit current through the circuit to a specified value.
• Given the schematic of an incandescent lighting circuit, calculate its total current and select the appropriate protective fuses.
• Describe the effects of opens and shorts in series and parallel circuits.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Most electric power is generated and consumed in the form of alternating current (AC), and most meters that measure energy consumption are designed to measure AC power. Many of the principles associated with direct current (DC) circuits also apply to AC circuits. This course describes variations that account for differences between DC power and AC power.

#### Learning Objectives

After completing this course, you will be able to:

• Define the terms “direct current” and “alternating current.”
• Explain the advantages and disadvantages of both direct current and alternating current.
• List the four ways to produce a DC voltage.
• Explain the development of a sine-wave output in an AC generator.
• Define the following terms in relation to AC generation: radians/second, hertz, and period.
• Define the effective value of an AC current relative to DC current.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Grounding is the chief means of protecting life and property from electrical hazards such as lightning, line surges, short circuits, and ground faults. Grounding also helps ensure the proper operation of a system. This course provides an overview of what grounding is, why it is necessary, and effective grounding techniques.

#### Learning Objectives

After completing this course, you will be able to:

• Define the term “grounding” and why it is necessary.
• Explain common problems that can occur in grounding systems.
• Describe the types of grounded electrical systems.
• Explain basic requirements for equipment grounding and bonding.
• Describe the importance of an effectively grounded system.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Insulators, or nonconductors, are materials with electrons that are tightly bound to their atoms and require large amounts of energy to free them from the influence of the nucleus. Examples of insulators are rubber, plastics, glass, and dry wood. This course introduces participants to electrical insulators and their physical properties. In addition, it describes the various uses of insulators as well as some of the materials that are used as insulators.

#### Learning Objectives

• Define an electrical insulator.
• Describe the physical properties of an insulator.
• Identify uses of insulators.
• Describe some of the materials used as insulators.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English
Capability: Audio, Video

The relationship between current, voltage, and resistance was described by George Simon Ohm in a form that is commonly referred to as Ohm’s Law. Ohm’s Law states that current is equal to voltage divided by resistance. This law is often expressed using symbols for each quantity. This course describes Ohm’s law; the units in which power is measured; and how to solve for power, voltage, current, and resistance using Ohm’s Law.

#### Learning Objectives

• State the simple form of Ohm’s Law as it applies to voltage, current and resistance.
• Given two of the three values of voltage, current, and resistance, solve for the remaining value using Ohm’s Law.
• Define the term “power” and the units in which it is measured.
• Discuss the more complex form of Ohm’s Law, which brings power into the equation.
• Solve for various values of power, voltage, current, and resistance using Ohm’s Law.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English
Capability: Audio, Video

Sources of electricity typically refer to the different types of fuel or power used to generate electricity. With the exception of solar power, these sources all involve spinning a copper wire between magnets. This course describes how electricity is produced through electrochemical production, magnetic induction, and the photoelectric effect.

#### Learning Objectives

• Describe the electrochemical production of electricity.
• Describe how magnetic induction produces electricity.
• Describe the photoelectric effect and how it produces electricity.
• Discuss thermoelectricity and its uses.

Duration: 1.00 Hr

Course Level: Intermediate
Languages: English
Capability: Audio, Video

The relationship between current, voltage, and resistance was described by George Simon Ohm in a form that commonly is referred to as Ohm’s law. Ohm’s law states that current is equal to voltage divided by resistance. This law is often expressed using symbols for each quantity. The letter I is used to represent current, E represents voltage, and R represents resistance. Using these symbols, Ohm’s law can be expressed as I=E/R. Kirchhoff’s two laws also reveal a unique relationship between current, voltage, and resistance in electrical circuits that is vital to performing and understanding electrical circuit analysis. In this course, participants will learn how to use these laws when working with direct current (DC) circuits.

#### Learning Objectives

• State the simple form of Ohm’s law as it applies to voltage, current, and resistance.
• Explain the more complex form of Ohm’s law, which brings power into the equation.
• Solve for various values of power, voltage, current, and resistance in a DC circuit using Ohm’s law.
• Discuss Kirchhoff’s voltage and current laws.
• Given a complex DC circuit, solve for current and voltage using Kirchhoff’s voltage and current laws.