| In the Philippines, teachers focus more on the definition of electricity and the people who discovered it than on how it is produced in the first place. We know that Benjamin Fraklin, the greatest American statesman and inventor, was the one who discovered the nature of electricity through his experiments with lightning in 1740s. Thomas Edison applied electricity to light a bulb in 1879 while Nikola Tesla developed a system of generating and transmitting alternating current (AC) electricity in the 19th Century. James Watt, on the other hand, invented the steam engine, which remains the basic structure of most engines and power generators to this day. But the real challenge for Filipino educators is to explain to their students how electricity is generated. Our crude interpretation is that electricity is a reaction from the process of rubbing two objects. Others call electricity as a form of energy or a force, but this remains debatable. The fact is we need to apply energy or force to release electricity. Lightning is electricity, which is produced by force - the violent movement of winds in the sky. When we rub two stones for a certain period, a spark is produced, and the two objects become hot. Electricity is released. A more precise definition could be electricity is the surge of electrons. Every object is composed of atoms. In every atom there is the nucleus or the center which is surrounded by negatively charged particles called electrons. Inside the nucleus are positively charged particles called protons and uncharged particles called neutrons. Now, a balance between the number of protons and electrons exists in most atoms, but when this balance is disrupted by a force such as the rubbing of two objects, some electrons are released - a process called electric current. To release electricity, we need to apply force first to drive electrons from an object. The most common force applied to achieve this is magnetism which is also known as electromotive force. Here, the spinning of a copper coil within a magnetic field will produce a force that will push the electrons through a circuit. This push is called voltage. Most power generators are built this way, with a copper coil spinning within a magnetic field to generate electricity. A coil serves as a conductor. By rotating a magnetic field around the conductor or the conductor within the magnet, electricity is produced and each time the conductor travels through the magnetic field, a voltage is created. The mechanical energy of the spinning coil transforms to electrical energy in the wire. In other words, electricity generation is based on the relationship between magnetism and electricity. When a wire moves across a magnetic field, an electric current occurs in the wire. Put it simply, a power generator needs magnets, coiled copper wire and spinning motion to generate electric current. But to enable the magnetic field to spin, a force is needed. Most power generators have turbines that are connected to the magnet, so that the spinning will be caused first by the blades of the turbine. What will cause the spinning motion depends on the type of energy source: coal-fired, diesel oil, wind-powered, hydroelectric, gas turbine, nuclear (uranium), geothermal, solar or others. We can use actual motion or steam to spin the turbine. Wind-mills use the spinning motion to push the turbine blades and turn the copper coil in the generator and eventually generate electric current. The same principle applies to hydroelectric turbine or wheel, where water flows provide the force to move the turbine blades. In case of fuel-powered plants, a boiler is set up to burn fuel and produce heat, which will transform water stored in long vertical tubes into steam. As the water begins to boil, the highly pressurized steam rises through the pipes and blows against the turbine blades, causing the spinning motion. Fuel includes natural gas, coal and diesel. The same principle of spinning the turbine blades through steam pressures applies to plants powered by nuclear, geothermal, solar and biomass energy. Steam turbines spin at about 3,600 revolutions per minute. With the spinning motion of the turbine and the copper coil, electricity is generated and runs through the wires or electric circuit which is connected to our homes via transformers. When electricity flows through a light bulb's filament, the electricity appears as light. Power plants' transformers increase the voltage of the electricity to make it travel through the distribution lines more efficiently until the electricity reaches to substations where separate transformers reduce the voltage again for consumer use. Electricity travels at lightning speed. Households regulate the use of electricity by switches, which open or close the electricity circuit. Basically, electricity consumption is measured by a unit of power called watts. A kilowatt is equal to 1,000 watts. The unit kilowatthour, on the other hand, represents the use of electricity for a certain number of hours. |
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