(Essentially, two hot wires share a neutral wire.) This circuit is also known as the "Edison Circuit." common neutral circuit configuration. The term "common" refers to the fact that all the wires involved are connected to one side of a bus or circuit breaker. The opposite side of this bus or breaker serves as the second set of oppositely-connected wires for the other three legs of the power triode. These four wires are then bundled together and fed into the body of the radio where they are connected to the anode and cathodes of the vacuum tube.
In most homes, the black and white wires are part of a single circuit, while the red wire is separate. If you were to remove both the black and white wires from their respective outlets at home, there would be no way to supply power to any other devices because there are no other wires available to connect to. However, if you were to remove only the white wire, it would be possible to turn on the lights by using the black and red wires from another outlet instead. Lights would still work because these other two wires are part of the same circuit with the white one that was removed.
Thus, the channel of current flow is completed by two wires, and this path is referred to as an electric circuit. To halt the flow of current, an electric circuit must be closed. Such a circuit cannot conduct electricity. With two wires, an electric circuit is complete. Without these two wires, the circuit is not complete.
In electrical engineering, a circuit is any closed loop for transmitting or receiving electrical signals or currents. Circuits are used in communication systems, power distribution networks, and other devices that use electricity.
A circuit can be anything that connects two points together. For example, a circuit could be a metal wire between two terminals in a light fixture. The wire is connected at one end to one terminal and at the other end to the other terminal. In this case, the circuit is complete because it connects one side of the light bulb to the other side. Without the wire, there would be no connection and thus no circuit.
Electric circuits can be divided into two main categories: alternating-current (AC) circuits and direct-current (DC) circuits. Alternating-current circuits use a voltage that switches back and forth between two different levels. Direct-current circuits always have only a single level of voltage. Most circuits that you encounter will be alternating-current circuits. Electricity must be flowing through the circuit in order to transmit information, so all circuits require at least two connections for the transmission of signals.
In the United States, the common wire is often white and is referred to as the neutral wire. It's also known as common since all circuits in the home often have the white wires linked together, implying that every circuit shares that wire. The term "neutral" comes from the fact that early telephone systems were not complete networks - they had single wires running between each phone terminal or station. A third term, "ground", refers to a metal rod inside walls and floorboards used to link all other wires together so that current can flow in one direction only.
In older homes where there are no ground wires, people will sometimes connect the black and red wires together as well. While this does provide some limited electrical service, it's not recommended because if you ever have anyone come into contact with these wires while they're live, they could be injured by an electric shock.
The term "commons" comes from the old wiring system where all the wires ran up on posts and were tied together at certain points called commons. Today, most houses are wired using aluminum or steel cables with each cable carrying several pairs of wires: one pair for hot wires, another for neutral wires, and a third for ground. But even today, some older homes are still wired with copper wiring which feeds specific rooms with electricity.