The term current refers to the simple flow of electrons in a circuit or electrical system. You can also liken electrical current to the quantity, or volume, of water flowing through a water pipe. Electrical current is measured in amperage or amps. Electrical current exists in two types: alternating current AC and direct current DC. Technically, DC current flows in one direction only, while AC current reverses direction.
In everyday terms, AC is the form of generator-created electricity that operates lights, appliances, and outlets in your home, while DC is the form of power provided by batteries. For example, your flashlights are DC systems, while your home's outlets use an AC system.
Many renewable energy sources such as solar and wind generators, produce DC electricity that is converted to AC for use in the home. An automobile's battery is a DC system used to start the engine, but once the engine is started, the automobile's electrical system has an alternator that begins to create AC current to run the various systems. Voltage, also known as electromotive force , is often defined as the pressure of the electrons in a system. It can be likened to the water pressure in a pipe.
The standard circuits in your home carry either about volts the actual voltage can vary between about to volts or volts actual range: about to volts. Most light fixtures and outlets are fed by volt circuits, while dryers, ranges, and other large appliances typically use volt circuits. The term wattage refers to the rate at which electrical energy is dissipated, or consumed.
The total amount of power consumed by the electrical system in your home is read through the utility company's electric meter. It is measured in kilowatt-hours or 1, watt-hours, and that is how you are billed. Each electrical device, such as a light fixture or appliance, has a rate of usage measured in watts. For example, a watt light bulb burning for 10 hours uses one kilowatt-hour of electricity.
Ohms are the measurement of resistance to the flow of electrons through a conductive material. The higher the resistance, the lower the flow of electrons. This resistance causes a certain amount of heat to be generated in the circuit. Generators can be powered by steam turbines heated by coal, natural gas, oil or a nuclear reactor. They can also be powered by wind turbines or water turbines in hydroelectric dams. From the generator, the current goes through a series of transformers , where it is stepped up to a much higher voltage for transmission.
The reason for this is that the diameter of the wires determines the amount of current, or amperage, they can carry without overheating and losing energy, but the voltage is limited only by how well the lines are insulated from the ground. It is interesting to note that the current is carried by only one wire and not two. The two sides of direct current are designated as positive and negative. However, because the polarity of AC changes 60 times per second, the two sides of alternating current are designated as hot and ground.
In long-distance power transmission lines, the wires carry the hot side, and the ground side travels through the Earth to complete the circuit. Since power equals voltage times amperage, you can send more power down the line at the same amperage by using higher voltage. The high voltage is then stepped down as it is distributed through a network of substations until it gets to the transformer near your house, where it is finally stepped down to V. In the United States, wall sockets and lights run on V at 60 Hz.
In Europe, nearly everything runs on V at 50 Hz. Once the current gets to the end of the line, most of it is used one of two ways: either to provide heat and light through electrical resistance, or mechanical motion through electrical induction. A hair dryer, for example, uses both at the same time. This brings us to an important feature of electric current: it can do work.
It can light your home, wash and dry your cloths, and even raise your garage door at the flip of the switch. What is becoming more and more important, though, is the ability for electric current to convey information, most notably in the form of binary data.
Although the Internet connection to your computer uses only a tiny fraction of the electric current of, say, an electric heater, it is becoming more and more important to modern life.
Site Map Employee Directory. Nearly everything we know about in our everyday life tends to wear out. It seems natural for someone to wonder if the wires that carry electricity wear out as electricity flows through them. To answer this, first think of a wire as a conduit that has something flowing through it. If the conduit is absolutely full, whenever a quantity of material flows in one end an equal amount of material must flow out the other end. Such is the case with electricity.
The material flowing in wires carrying electricity is electrons and when a given number of electrons flow into a wire, an equal number must flow out. The wire is simply a pathway for the electrons to travel. Wires are made of metals, which are conductors. Conductors have some electrons that are rather free to move.
Electric current electricity is a flow or movement of these electrons through the conductor. The amount of current flowing is given in units called amperes. These electrons are forced to move by an electrical potential difference between two points in the wire. This potential difference can be created by a battery, generator, solar cell, or similar device and is expressed in units called volts. Consider a wire connected to the terminals of a battery with a given potential difference voltage.
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