Just as there are a variety of technologies available in conventional vehicles, plugin electric vehicles also known as electric cars or evs have different capabilities that can accommodate different drivers needs. This video explains electricity as the flow of atomic particles called electrons. This electric current can be direct or alternating. On the other hand, insulators or dielectrics, like plastics and polymers, have low conductivity values.
Define resistivity of a material and apply formulas for its calculation. Thats the principle of the electric motor, but for the next 50 years, motors were toys. Define and apply the concept of temperature coefficient of resistance. If you want to break it down to electrical basics, electricity is essentially the flow of electrical current, power or charge. Apr 20, 2015 a video describing the electricity for better understanding. When beginning to explore the world of electricity and electronics, it is vital to start by understanding the basics of voltage, current, and resistance. Fundamentals of electricity there is a definite relationship between the three primary electrical characteristics. This singledirection flow of current is called a direct current, or dc. Current electricity notes class 12th pdf download physics.
The current in a circuit is directly proportional to the applied voltage and inversely proportional to the amount of resistance. Distribution line a line that carries electricity at lower voltages of 12kv to 44kv and is used to distribute power. Electric basics electrical fundamentals and terms explained. The flow of free electrons in the same general direction from atom to atom is referred to as current and it is measured in amperes amps or a. Write and apply ohms law s law to circuits containing resistance and emf. See these pictures of early electric motors, only the latest of which are commercial. Such current is used in your household to run the air conditioner, refrigerator, washing machine, and other electric. Direct current dc electric current flows continuously in the same direction as contrasted with alternating current. The history of electricity starts more than two thousand years ago, with the greek philosopher thales being the earliest known researcher into electricity.
From the power plant, the electric current travels on highvoltage. Either way, current is what happens when the random exchange of electrons that occurs constantly in a conductor becomes organized and begins to move in the same direction. Ohms law is the relationship between power, voltage, current and resistance. A major feature of evs is that drivers can plug them in to. Let us now see what happens to such a piece of conductor if an electric field is applied.
Micrologic trip systems use a set of current transformers called cts or sensors to sense current, an electronic trip unit to evaluate the current, and a tripping solenoid to trip the circuit breaker. A german mathematician, george simon ohm, formulated this relationship in the 19th century. Electric current refers to the flow of the electric charge carried by electrons as they jump from atom to atom. Essentially, flow of electrons in an electric circuit leads to the establishment of current.
The number of electrons that flow through a conductor s crosssection in one second determines amps. An introduction to electric power transmission presentation. The first phenomenon used in transformers is that when a wire carries an electric current, it generates a. Jun 08, 2016 this video in hindi is explaining the fundamentals of electric current. Highvoltage lines carry the current to substations on the power grid. Electronic trip circuit breaker basics schneider electric. The strength of an electric current is measured with a unit called the ampere, sometimes used in the short form amp or abbreviated a. About the tutorial current affairs 2018, apache commons. It is measured in amperes or simply amps, and denoted by the letter i or lower case i. Resistors allow current to flow to some degree in proportion to their resistance in ohms. When you turn on a light switch, electric current flows from the switch through the wire to the light, and the room is instantly illuminated.
Electric current is a measure of the flow of charge, as, for example, charge flowing through a wire. Never connect any component or lead to electrical outlets in any way. While operating principles of transformers remain the same, the challenges of maintaining and testing transformers have evolved along with transformer design and construction. It occurs both naturally in our environment in the form of lightening and is also produced from the conversion of other primary sources of energy, such as coal, nuclear or solar energy. In an electrical circuit, the current flows from the point where the electrical potential is highest to the point where it is lowest.
When electrons leave their orbits, they are referred to as free electrons. Electrical current flows from a region of high charge or potential to a region of low potential. The current in electronic circuits is usually much smaller than current in electrical devices like light bulbs and hair dryers. By knowing this simple law, you understand the concept that is the basis for the analysis of any electrical circuit. As such, current is analogous to the number of gallons of water flowing into, along, and out of a slide per unit of time.
Inverters and ac converters based on completely controllable switches. Refer to sections 1, 2 and 3 in chapter 1 of your text electric circuit. Also, as the resistance goes up, the current goes down, and vice versa. This current varying in parallel circuits brought about kirchoffs next big law in basic electrical engineering, kirchoffs current law kcl. His law ohms law stated that current is directly proportional to voltage and inversely proportional to. Basics on electricity and electrical generation ej moyer, u. Define electric current electric current and electromotive force. Power, in watts, is a measure of electrical energy. Electricity basics electrical charge voltage current resistance ohms law an ohms law experiment resources and going further electricity basics when beginning to explore the world of electricity and electronics, it is vital to start by understanding the basics of voltage, current, and resistance. Practical implementation of fundamental theory concepts. An alternating currentac is a current that varies sinusoidally with time. The substances which have a large number of free electrons and offer a low resistance are called. This conversion is usually obtained through the generation of a magnetic field by means of a current flowing into one or more coils. Tlc recommends that you download and save this pdf document and.
Bee basic electric engineering is common to first year branches of ug engineeringexpect bt. Electrical fundamentals general electricity is a form of. In the next sections, we shall study the steady current that results from a steady electric field in conductors. Know the fundamental of electrical engineering and practical. Electric current is the rate at which electric charge flows past a point on the electric circuit. The ampere is nothing more than a measurement of how many charge carriers in most cases, electrons flow past a certain point in one second.
At least one of the two magnetic field is generated by a solenoid carrying a current. Printable science worksheets on current electricity, circuits, consudtors and insulators, and static electricity. Intro to electricity nyu tandon school of engineering. In this article we will learn about the basics of electric current, sources and uses. Voltage and current are not measurements of electric power and work. Lesson 7 december 8th, 2011 the class will be split into two groups one group will take a note the other group will conduct a lab half way through the class the two. This means that if the voltage goes up, the current flow will go up, and vice versa. At the end of the course the student is expected to 1. This video in hindi is explaining the fundamentals of electric current. Work, in wattseconds or watthours, is a measure of the energy used in a period of time. Test each object to determine if it is a conductor of electricity or an insulator. The electric motor operation is based on the following points.
You will learn the basics of electrical principles, distribution and. Current flow in a circuit is normally designated by the letter i, and this letter is used in equations like ohms law where vi. Similarly, a coil of wire with a current passing through it generates a magnetic field. Mechanical energy what is an electric motor an electric motor is a device converting electrical energy into mechanical energy usually a torque. Electric current in reality in metallic conductors current is. Introduction to dc circuits electric voltage and current. A video describing the electricity for better understanding. In practical, no current source can be ideal, practical current source is always shown with resistance in parallel. Electricity basics electrical charge voltage current resistance ohms law an ohms law experiment resources and going further. Current i current is the quantity of electrons passing a given point. The phase relation between the rotor and stator magnetic field i. The rate of flow of chrge through the conductor is called electric current. The direct current dc flows in a unidirectional way and generally it is produced by batteries, solar cells, thermocouples, etc.
But for now, well just concern ourselves with dc circuits. Electric theory, quantities and circuit elements current typical current levels. Labview package and driver installation tutorial for engr 190. The basic concept of current is that it is the movement of electrons within a substance.
Basics of electric current and their uses engineering portal. A common form of timevarying current is the sinusoidal current or alternating current ac. Current electricity 95 number of electrons travelling in any direction will be equal to the number of electrons travelling in the opposite direction. This module will cover the fundamentals of electricity in a practical way, and will not be complicated by complex theory and mathematical calculations. A system that converts electric energy to an electric load through a control circuit is known as a power electronic system. Ppt current electricity and electric circuits powerpoint. Water current is the rate at which water flows past a point on the water circuit.
Now you should understand the concepts of voltage, current, resistance, and how the three are related. A circuit is an interconnection of electrical components. Thick wires carry the electric current from the generator to a transformer, which increases the voltage of the electric current to 500,000 volts or more, before electricity can be sent to the power grid. Electric circuits electricity means the flow of electric current. Download principles of electric machines and power electronics pdf. I direct current dc modern life could not exist if it were not for electricity and electronics. This module describes the basic concepts of direct current dc electrical circuits. In the second volume of this book series, electric circuits are explored where the direction of current switches back and forth. A timevarying current is represented by the symbol i. So now we know that a current can create a magnetic field.
Electric vehicles just as there are a variety of technologies available in conventional vehicles, plugin electric vehicles also known as electric cars or evs have different capabilities that can accommodate different drivers needs. Current current moves through a circuit element through variable. Current flow in a conductor wire or any element is specified by two indicators. Define and apply the concept of temperature coefficient of. Aims by the time you have finished with this chapter you should have a good understanding of the nature of electric current and its effects, including the processes of energy transfer and mass transfer. When you turn on a light switch, electric current flows from the switch. Current electricity notes class 12th pdf download physics tutoria. By the late 1880s, power demand for electric motors required 24hour service and dramatically raised electricity demand for transportation and other industry needs.
A convention is a standard way of describing something so that others in. If a magnetic field can create a current then we have a means of generating electricity. It then goes on to define an electric current and describe the basic principles of generating electricity from chemical reaction and then finally from. An electric current is produced when free electrons move from one atom. Cell phone battery charger 5 amps 5ma 5 milliamps sensation. An electrical current is the movement of negative electrical charges electrons through a conductor electrical wire, metal foil, etc. The size of the current learn why coppers low resistance makes it an excellent conductor of electrical currentsthe relationship between current and resistance in an electric circuit. The electrical science fundamentals handbook was developed to assist. So the electric charges can travel through them very easily, with a high speed and in large amounts.
Micrologic trip units allow the user to set the proper overcurrent or ground current protection required in the electrical system. The majority of equations and laws for analyzing circuits can be derived directly from ohms law. An alternating current ac is a current that varies sinusoidally with time. Conductors allow electrical current to easily flow because of their free electrons. Some atoms have one or two electrons in the outer shell and on application of energy, these electrons are free electrons. An ideal current source is one which delivers a current of constant magnitude, totally independent of the external network connected.
The edison tech centers diverse material covers the engineering and applications side of electricity the fun part. A free powerpoint ppt presentation displayed as a flash slide show on id. Flow of electric current through a conductor experiences a certain amount of resistance. An electric circuit is a complete path through which electricity travels circuits are made up of wires and electrical parts such as batteries, light bulbs, resistors, motors and switches a circuit diagram is a shorthand method of describing a working circuit. Current is rate of flow of negativelycharged particles, called electrons, through a predetermined crosssectional area in a conductor. Electric current is defined as the rate of flow of electric charge through a conductor. Thats the principle of the electric motor, but for the next 50 years, motors were toys and laboratory demonstrations only.
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