What is an Electric Circuit?
A system of conducting elements that are designed to conduct electric current for a particular purpose is known as an electric circuit. An electric circuit consists of a source of electrical energy; elements that either transform, dissipate, or store this energy; connecting wires. To prevent power overload, circuits often include fuse or circuit breaker.
A Short History of Circuits and Systems
The first electric circuit was invented by Alessandro Volta in 1800. Volta discovered that he could produce a steady flow of electricity using bowls of salt solution connected by metal strips. Later, he used alternating discs of copper, zinc, and cardboard that had been soaked in a salt solution to create his voltaic pile (an early battery). He successfully made the electric current to flow through the circuit by attaching a wire running from top to bottom. The first practical use of electric current was employed in electrolysis, which further led to the development of new chemical elements.
Components of an Electric Circuit
Electric circuits are amazing. Have you ever seen the game of Steady Hands? It is a circuit with a twisty wire between two points. The point of the game is to move a metallic object from one end of the electric wire to the other. If you touch the wire while moving this metallic object, the circuit buzzes and you are out. It’s a really fun game that can be made with stuff you can find at home. Let’s analyse an electric circuit and dive deeper into its components.
Electric Circuit Components with Symbols
- The Electric Cell (Dry Cell): The electric cell also known as a dry cell is the main component of the electric circuit. This provides our tools and devices with electrical energy to do work. The cells have a positive and negative terminal. If you pick up a normal AA or an AAA cell, the end of the cell that is smooth is the negative pole and the end with a cylinder jutting out is positive. This is represented in an electric circuit as two parallel lines of unequal length.
In the representation, the longer line represents the positive end and the shorter line represents the negative terminal. You definitely must have heard the term Battery. Battery refers to a combination of cells and is used when a single cell cannot supply enough electrical energy by itself. It is important to remember that while connecting two cells, the opposite terminals should be connected together. Such connections can be seen in remotes where you have to put two cells. Other examples of batteries include the large ones used in lorries and cars.
- Electric Bulb: The electric bulb here represents the component of the electric circuit that is doing the work with the electrical energy of the cell. In this case, the bulb uses the electrons to heat up the filament in the bulb and create light. This bulb can be replaced in the circuit with a variety of things, such as fans, refrigerator depending on the electric circuit being discussed. The symbol for a bulb is;
- Electrical Switches: Electric circuits don’t need to be working constantly. You need the fan only when you are at home and when you are going out you switch it off. The on-off switching is possible because of electrical switches. For an electric circuit to do work, the electricity has to be flowing and it should be continuous. If there is a discontinuity in an electric circuit, no work is possible.
- Electrical Wiring: If electric circuits can be linked to cities, the electrons are the work force, the batteries supply the work force, the bulb is where the work force goes to work in the electric circuit. Here the electrical wiring plays the role of a highway. Electrical wiring consists of thin conducting wires that allow electrons to pass from one component to another and complete the circuit.
Electric switches are like bridges, in the ON position, the circuit is continuous and the electrons can pass over the bridge to the other side to do work. In the OFF position, the bridge is broken thereby not allowing electrons to pass through which means that the bulb is not getting any energy do work. When switch is off, electrical current cannot flow through the electric circuit.
Watch the video below to learn more about electricity and resistance,
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