1. “Electricity”

2. Index: What is electricity ? ……………………… 1 Electicity ………………………………………. 2 How is electricity measured ………….. 3 How is electricity generated ………….. 4

3. Electricity is a form of energy. Electricity is the flow of electrons. All matter is made up of atoms, and an atom has a center, called a nucleus. The nucleus contains positively charged particles called protons and uncharged particles called neutrons. The nucleus of an atom is surrounded by negatively charged particles called electrons. The negative charge of an electron is equal to the positive charge of a proton, and the number of electrons in an atom is usually equal to the number of protons. When the balancing force between protons and electrons is upset by an outside force, an atom may gain or lose an electron. When electrons are "lost" from an atom, the free movement of these electrons constitutes an electric current. Electricity is a basic part of nature and it is one of our most widely used forms of energy. We get electricity, which is a secondary energy source, from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. Many cities and towns were built alongside waterfalls (a primary source of mechanical energy) that turned water wheels to perform work. Before electricity generation began slightly over 100 years ago, houses were lit with kerosene lamps, food was cooled in iceboxes, and rooms were warmed by wood-burning or coal-burning stoves. Beginning with Benjamin Franklin's experiment with a kite one stormy night in Philadelphia, the principles of electricity gradually became understood. In the mid- 1800s, everyone's life changed with the inventionof the electric light bulb. Prior to 1879, electricity had been used in arc lights for outdoor lighting. The lightbulb's invention used electricity to bring indoor lighting to our homes.Benjamin Franklin'slight bulb 1

4. Electricity is the set of physical phenomena associated with the presence and flow of electric charge. Electricity gives a wide variety of well-known effects, such as lightning, static electricity, electromagnetic induction and the flow of electrical current. In addition, electricity permits the creation and reception of electromagnetic radiation such as radio waves.electric chargelightningstatic electricityelectromagnetic inductionelectrical current electromagnetic radiationradio waves In electricity, charges produce electromagnetic fields which act on other charges. Electricity occurs due to several types of physics:electromagnetic fields electric charge: a property of some subatomic particles, which determines their electromagnetic interactions. Electrically charged matter is influenced by, and produces, electromagnetic fields. electric chargesubatomic particleselectromagnetic interactions electric current: a movement or flow of electrically charged particles, typically measured in amperes. electric currentamperes electric field (see electrostatics): an especially simple type of electromagnetic field produced by an electric charge even when it is not moving (i.e., there is no electric current). The electric field produces a force on other charges in its vicinity. Moving charges additionally produce a magnetic field. electric fieldelectrostaticselectric currentmagnetic field electric potential: the capacity of an electric field to do work on an electric charge, typically measured in volts. electric potentialworkelectric charge volts electromagnets: electrical currents generate magnetic fields, and changing magnetic fields generate electrical currents electromagnets In electrical engineering, electricity is used for:electrical engineering electric power where electric current is used to energise equipment electric power electronics which deals with electrical circuits that involve active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies. electronicselectrical circuitsactive electrical componentsvacuum tubestransistorsdiodesintegrated circuits Electrical phenomena have been studied since antiquity, though advances in the science were not made until the seventeenth and eighteenth centuries. Practical applications for electricity however remained few, and it would not be until the late nineteenth century that engineers were able to put it to industrial and residential use. The rapid expansion in electrical technology at this time transformed industry and society. Electricity's extraordinary versatility as a means of providing energy means it can be put to an almost limitless set of applications which include transport, heating, lighting, communications, and computation. Electrical power is the backbone of modern industrial society, and is expected to remain so for the foreseeable future. [1]engineerstransportheatinglightingcommunications computation [1] The word electricity is from the New Latin ēlectricus, "amber-like" [a], coined in the year 1600 from the Greek ήλεκτρον (electron) meaning amber, because electrical effects were produced classically by rubbing amber.New Latin [a]amber 2

5. Electricity is measured in units of power called watts. It was named to honor James Watt, the inventor of the steam engine. One watt is a very small amount of power. It would require nearly 750 watts to equal one horsepower. A kilowatt represents 1,000 watts. A kilowatt-hour (kWh) is equal to the energy of 1,000 watts working for one hour. The amount of electricity a power plant generates or a customer uses over a period of time is measured in kilowatthours (kWh). Kilowatthours are determined by multiplying the number of kW's required by the number of hours of use. For example, if you use a 40-watt light bulb 5 hours a day, you have used 200 watts of power, or.2 kilowatthours of electrical energy.James Watt steam engine 3

6. An electric generator is a device for converting mechanical energy into electrical energy. The process is based on the relationship between magnetism and electricity. When a wire or any other electrically conductive material moves across a magnetic field, an electric current occurs in the wire. The large generators used by the electric utility industry have a stationary conductor. A magnet attached to the end of a rotating shaft is positioned inside a stationary conducting ring that is wrapped with a long, continuous piece of wire. When the magnet rotates, it induces a small electric current in each section of wire as it passes. Each section of wire constitutes a small, separate electric conductor. All the small currents of individual sections add up to one current of considerable size. This current is what is used for electric power. 4

7. Reference sources: http://en.wikipedia.org/wiki/Electricity http://www.mcwdn.org/Physics/Electricity.htm lhttp://www.mcwdn.org/Physics/Electricity.htm l http://www.energyquest.ca.gov/story/chapter0 2.htmhttp://www.energyquest.ca.gov/story/chapter0 2.htm http://inventors.about.com/library/inventors/bl electric1.htmhttp://inventors.about.com/library/inventors/bl electric1.htm

8. Conclusion: Electrcity helps us in lots of ways, It helps us watch television, play computer games and bathe. Without electrcity a lot of things we take for granted wouldn't be here today. Imagine living inn the dark with no central heating or television or computer? How bad would that be? It would be the middle ages all over again.