Basics of Electricity
The basics of electricity involve the study of electric charge, current, voltage, and resistance. Electric charge is the fundamental property of matter that creates electric fields, while current is the flow of electric charge. Voltage is the difference in electric potential between two points, and resistance is the opposition to the flow of electric current in a material.
8 Key excerpts on "Basics of Electricity"
eBook - ePub- S. Bobby Rauf(Author)
- 2020(Publication Date)
- CRC Press(Publisher)
...1 Fundamental Electrical Engineering Concepts and Principles Introduction In this first chapter of the Electrical Engineering Fundamentals text, we will explore fundamental electrical engineering terms, concepts, principles, and analytical techniques and impart knowledge that is considered elemental in the discipline of electrical engineering. Readers who invest time and effort in studying this text are likely to do so for the key purpose of gaining an introduction into the field of electricity. In this chapter, we will lay the foundations in the electrical engineering realm by covering basic electrical engineering terms, concepts, and principles, without the understanding of which, discussion and study of terms that bear important practical significance, such as power factor, real power, reactive power, apparent power, and load factor, would be untenable. Most of the material in this chapter pertains to DC, or direct current, electricity. However, some entities discussed in this chapter such as capacitive reactance, inductive reactance, and impedance are fundamentally entrenched in the AC, alternating current, realm. This text affirms that electrical engineering is rooted in the field of physics and chemistry. Physics, chemistry, and electrical engineering, as most other subject matters in science, depend on empirical proof of principles and theories. Empirical analysis and verification require tools and instruments for measurement of various parameters and entities. Hence, after gaining a better understanding of the basic electrical concepts, we will conclude this chapter with an introduction to three of the most common and basic electrical instruments, namely, multi-meter, clamp-on ammeter, and a scope meter or oscilloscope. Voltage or EMF (Electromotive Force) Voltage can be defined as a “force” that moves or pushes electrically charged particles like electrons, holes, negatively charged ions, or positively charged ions by forming an electric field...
- S. Bobby Rauf(Author)
- 2021(Publication Date)
- River Publishers(Publisher)
...Chapter 1 Electrical Engineering Basics and Direct Current Introduction In this chapter, we will explore the basics of electrical engineering terms, concepts, principles, and analytical techniques. Many readers who embark on investing time and effort in studying this text are likely to do so for the key purpose of gaining an introduction into the field of electricity. Many others, on the other hand, might be interested in refurbishing prior knowledge of electrical engineering terms, concepts, principles, and basic analytical techniques. Regardless of whether you belong to one of these two groups —or are simply in pursuit of electrical engineering at the intermediate or associate degree level — in this chapter we will lay the foundations in the electrical engineering realm by covering basic electrical engineering terms, concepts, and principles, without the understanding of which, discussion and study of terms that bear important practical significance, such as power factor, real power, reactive power, apparent power, load factor, etc. would not be feasible. Most of the material in this chapter pertains to DC, or Direct Current, electricity. However, some entities we will discuss in this chapter, such as capacitive reactance, inductive reactance, and impedance are fundamentally premised in the AC, Alternating Current, realm. Electrical engineering is largely rooted in the field of physics. Physics, and electrical engineering, as most other fields in science, depend on empirical proof of principles and theories. Empirical analysis and verification require measurement tools or instrumentation...
eBook - ePubInstrumentation
An Introduction for Students in the Speech and Hearing Sciences
- T. Newell Decker, Thomas D. Carrell(Authors)
- 2004(Publication Date)
- Psychology Press(Publisher)
...1 Introduction to Basic Electricity Almost without exception, when a person decides to use an instrument, it must first be connected to an electrical outlet. Because electricity is almost always available for our use, we tend to take it for granted, never questioning what it is or from where it comes. There are, however, some fundamental electrical concepts that are important to the overall understanding of clinical and laboratory equipment as it is discussed in later chapters of this book. But even more important, these concepts should be understood in order to operate instruments safely. This chapter contains a simplified discussion of where electricity comes from, what its basic parameters are, and how it can be used safely. Some simple equations and formulas illustrate the basic concepts, and you are encouraged to study them. ELECTRICAL FIELDS AND CHARGES Atoms are no longer thought of as the smallest particle of an element. We now know that atoms are made up of much smaller particles, some of which are: electrons, protons, and neutrons. Electrons and protons are the stuff of which electrical energy is made. Electrons have an electrical charge with a negative value, whereas protons have an electrical charge with a positive value. Both protons and electrons are of fundamental importance to the presence of electricity. Because neutrons have a neutral or zero charge, we will not be concerned with them in this chapter. Figure 1.1 demonstrates a basic characteristic of electrical charges. Charges that are of the same value or sign will repel each other; charges that are of dif- FIG. 1.1. Polarity of electrical charges showing that different charges attract and similar charges repel. ferent values or signs attract. Most of us have demonstrated an analogous property to ourselves with magnets. If we hold the south poles of two magnets together and then release them, the magnets jump apart...
eBook - ePub- Gilbert M. Masters(Author)
- 2013(Publication Date)
- Wiley-IEEE Press(Publisher)
...CHAPTER 2 BASIC ELECTRIC AND MAGNETIC CIRCUITS 2.1 INTRODUCTION TO ELECTRIC CIRCUITS In elementary physics classes, you undoubtedly have been introduced to the fundamental concepts of electricity and how real components can be put together to form an electrical circuit. A very simple circuit, for example, might consist of a battery, some wire, a switch, and an incandescent lightbulb as shown in Figure 2.1. The battery supplies the energy required to force electrons around the loop, heating the filament of the bulb, and causing the bulb to radiate a lot of heat and some light. Energy is transferred from a source, the battery, to a load, the bulb. You probably already know that the voltage of the battery and the electrical resistance of the bulb have something to do with the amount of current that will flow in the circuit. From your own practical experience you also know that no current will flow until the switch is closed. That is, for a circuit to do anything, the loop has to be completed so that electrons can flow from the battery to the bulb and then back again to the battery. And finally, you probably realize that it does not matter much whether there is one foot of wire connecting the battery to the bulb, or 2 ft; but that it probably would matter if there is a mile of wire between itself and the bulb. FIGURE 2.1 (a) A simple circuit. (b) An idealized representation of the circuit. Also shown in Figure 2.1 is a model made up of idealized components. The battery is modeled as an ideal source that puts out a constant voltage, V B, no matter what amount of current, i, is drawn. The wires are considered to be perfect conductors that offer no resistance to current flow. The switch is assumed to be open or closed. There is no arcing of current across the gap when the switch is opened, nor is there any bounce to the switch as it makes contact on closure...
eBook - ePub- Howard W. Penrose(Author)
- 2014(Publication Date)
- Success By Design(Publisher)
...Chapter 2 Basic Electricity and Electro-Magnetism In order to understand the operation of an electric motor and its insulation system, a study of basic electricity and electric motor operation is necessary. For this, we will start with the makeup of the classical atom, or the Bohrs Model. For the purpose of this book, a full study of electricity and electro-magnetism is not necessary, just an understanding of the principles. Figure 9: Bohrs Model of the Atom In this model, the atom is represented as protons (positive charge) and neutrons (no charge) of equal numbers being orbited by electrons (negative charge). Some atoms have more electrons than protons and are considered negatively charged ions while some have fewer electrons than protons and are considered positively charged ions. Electrons can be gained and lost by some types of atoms easily. When an electron is emitted from an atom, a photon of light is also emitted at a specific frequency relating to the atom. When enough are emitted, they can be seen in the visible or invisible light spectrum. The number of protons and neutrons determine the atom’s atomic weight and what element it represents. How the atoms of materials act will determine if the material is a conductor, a dielectric or an insulator: Conductors: Have free electrons in the material that are easily directed. They are usually metals such as copper, aluminum, gold or platinum. Semi-Conductors: Also referred to as dielectrics have four valence electrons and will polarize when an electrical field is applied. Insulators: No free electrons and are inert when an electrical field is applied. Insulators include ceramics, glass and mica. Current, Voltage and Resistance Whether discussing the topic in terms of direct or alternating current, the basic elements of electricity include current, voltage and resistance. Current (I) is the flow of electricity much like the flow of water in a pipe...
eBook - ePubElectrical Engineering
Fundamentals
- Viktor Hacker, Christof Sumereder(Authors)
- 2020(Publication Date)
- De Gruyter Oldenbourg(Publisher)
...1 The basic physic principles and definitions 1.1 The simple circuit In everyday life, people do not distinguish between technically correct designations for electric quantities but abbreviate and incorrectly name it “electricity”. Colloquially, the expression “electricity bill” is used, when in reality the electrical energy consumption is meant; when an electrical accident happens, it is referred to as “electric shock”. A person with technical knowledge is aware that a flow of an electric charge is designated “electric current” and that the physical quantity of current (intensity) uses the unit ampere. Furthermore, an expert knows that it is the voltage (measured in volts) that drives the current and that resistance (measured in ohm) at constant voltage determines the current (Figure 1.1). To better understand the correlation between electric current, voltage and resistance, we look at the water cycle as analogue to the electric circuit. Figure 1.1: Correlation between current, voltage and resistance. Table 1.1: Water cycle as analogue to electric circuit. Water cycle (analogue) Electric circuit Figure 1.2: Closed water cycle. Figure 1.3: Closed circuit. The flow of water Q t is caused by the pressure difference Δ P generated by pump P. The current flow is caused by the potential difference (= voltage V) generated by the voltage source. The pressure difference Δ P determines the amount of water pumped via the load per time. The potential difference (voltage V) determines the electric charge per time (current I) flowing through the load. The pressure loss due to the resistance in the container C is as high as the pressure...
eBook - ePubEnergy Medicine - E-Book
The Scientific Basis
- James L. Oschman(Author)
- 2015(Publication Date)
- Churchill Livingstone(Publisher)
...Chapter 2 Basic Physics and Biophysics, Part I Electricity and Magnetism If you wish to understand the universe, think of energy, frequency, and vibration. Nikola Tesla Chapter Summary Every morning millions of people around the world awake to a tone or to music coming from an alarm clock or clock radio. In rural areas, the wake-up call may be the sound of a rooster or birds singing. Often the day begins with flipping a light switch, pressing a button on a coffee maker, turning on the stove to make breakfast, and starting the car. For some of us, starting the car takes place after we have unlocked the car door, either by turning the car key in the lock, or by pressing a button that unlocks the door with a radio signal. Each of these everyday events involves various forms of energy, conversions of energy from one type to another, the movement of energy from one place to another, and an incredible phenomenon called resonance. Resonance is the remarkable phenomenon that enables us to hear the rooster and see the light from a star – light that may have begun its journey to Earth long before we were born. Each of these events can teach us a piece of the story of energy medicine because the human body depends on electricity and resonant interactions, and all of these phenomena have profound medical implications. This chapter explores the basic physics that enables us to turn on a light and the biophysics that enables us to see that light. In discussing these events we will have to take a close look at such things as electrons, electric currents, and radio waves. If you are confused about these subjects, there is no reason for concern – some of the greatest minds in history have puzzled over what an electron really is, what magnetism is, how currents actually flow through wires, or how sound, light, and radio signals travel through space...
eBook - ePubElectromagnetics Explained
A Handbook for Wireless/ RF, EMC, and High-Speed Electronics
- Ron Schmitt(Author)
- 2002(Publication Date)
- Newnes(Publisher)
...A pump is connected to the water tank. The pump produces a pressure increase, which causes water to flow. The pump is like a voltage source. The water flows through the pipes, where frictional losses cause the pressure to drop back to the original “pressure potential.” The water then returns to the tank. From the perspective of energy flow, the pump sources energy to the water, and then in the pipes all of the energy is lost due to friction, converted to heat in the process. Keep in mind that this analogy is only an approximation, even at DC. Figure 1.2 A simple circuit demonstrating Kirchhoff’s voltage law (V= ν 1 + ν 2 + ν 3). Basic circuit theory can be thought of in the same manner. The current flows in a loop, or circuit, and is governed by Kirchhoff’s laws (as shown in Figures 1.2 and 1.3). Kirchhoff’s voltage law (KVL) says that the voltages in any loop sum to zero. In other words, for every voltage drop in a circuit there must be a corresponding voltage source. Current flows in a circle, and the total of all the voltage sources in the circle or circuit is always equal to the total of all the voltage sinks (resistors, capacitors, motors, etc.). KVL is basically a consequence of the conservation of energy. Kirchhoff’s current law (KCL) states that when two or more branches of a circuit meet, the total current is equal to zero. This is just conservation of current. For example, if 5amps is coming into a node through a wire, then 5amps must exit the node through another wire(s). In our water tank analogy, this law implies that no water can leave the system. Current can’t just appear or disappear. Additional rules of basic circuit theory are that circuit elements are connected through ideal wires. Wires are considered perfect conductors with no voltage drop or delay. The wires between components are therefore all considered to be at the same voltage potential and are referred to as a node. This concept often confuses the beginning student of electronics...
