Electricity is one of the most widely used forms of energy. Electricity can be defined as the flow of electrons or charge. Electric power is the amount of work done by an electric current in a unit time. When a current flows in a circuit with resistance, it does work. Devices can be made that convert this work into heat (electric heaters), light (light bulbs and neon lamps), or motion, i.e. kinetic energy (electric motors).
Electricity is a secondary source of energy, and is generated by the conversion of other sources of energy, such as coal, natural gas, oil, nuclear power and other natural sources, called as primary sources. The generation of electricity began approximately more than 100 years ago. It was Benjamin Franklin who suspected that lightning was an electrical current in nature, and wanted to check if his assumption was correct. He tested his idea to see if the lightning would pass through metal. He used a kite, to prove that lightning is a stream of electrified air, today known as plasma. His famous stormy kite flight in June of 1752 led him to develop many of the terms that we still use today when we talk about electricity: battery, conductor, condenser, charge, discharge, uncharged, negative, minus, plus, electric shock, and electrician. In the mid eighteenth century, i.e. 1879 Thomas Edison changed everyone’s life – inventing the first commercially practical incandescent electric light bulb. Thomas Edison in 1883 – 84, introduced the world’s first economically viable system of centrally generating and distributing electric light, heat, and power. Prior to 1879, electricity had been used in arc lights for outdoor lighting. Edison’s invention used electricity to bring indoor lighting to our homes.
The electro-mechanical approach described here (which uses electromagnetic induction to generate an alternating current) is just one way of producing electricity. There are also photoelectric, electro-chemical, electro-mechanical, and thermoelectric phenomena (just to name a few), which can be used to produce an electric charge or direct-current electricity.
Types of Electricity
There are two types of Electricity, Static Electricity and Current Electricity. Static Electricity is made by rubbing together two or more objects and making friction while Current electricity is the flow of electric charge across an electrical field.
Static electricity is when electrical charges build up on the surface of a material. It is usually caused by rubbing materials together. The result of a build-up of static electricity is that objects may be attracted to each other or may even cause a spark to jump from one to the other. For Example rub a baloon on a wool and hold it up to the wall.
Before rubbing, like all materials, the balloons and the wool sweater have a neutral charge. This is because they each have an equal number of positively charged subatomic particles (protons) and negatively charged subatomic particles (electrons). When you rub the balloon with the wool sweater, electrons are transferred from the wool to the rubber because of differences in the attraction of the two materials for electrons. The balloon becomes negatively charged because it gains electrons from the wool, and the wool becomes positively charged because it loses electrons.
Current is the rate of flow of electrons. It is produced by moving electrons and it is measured in amperes. Unlike static electricity, current electricity must flow through a conductor, usually copper wire. Current with electricity is just like current when you think of a river. The river flows from one spot to another, and the speed it moves is the speed of the current. With electricity, current is a measure of the amount of energy transferred over a period of time. That energy is called a flow of electrons. One of the results of current is the heating of the conductor. When an electric stove heats up, it’s because of the flow of current.
There are different sources of current electricity including the chemical reactions taking place in a battery. The most common source is the generator. A simple generator produces electricity when a coil of copper turns inside a magnetic field. In a power plant, electromagnets spinning inside many coils of copper wire generate vast quantities of current electricity.
There are two main kinds of electric current. Direct (DC) and Alternating (AC). It’s easy to remember. Direct current is like the energy you get from a battery. Alternating current is like the plugs in the wall. The big difference between the two is that DC is a flow of energy while AC can turn on and off. AC reverses the direction of the electrons.