# What Does an Electrical Circuit Mean? Definition and Parts

Electrical circuits consist of a system formed by a set of connected electrical elements. It has one or more closed paths that can be traversed by an electric current.

An electric current is the movement of free electric charges in an orderly manner. Usually, these charges are electrons that move from the negative terminal to the positive terminal. Depending on the movement that the electric charges describe, we distinguish two types of currents: direct current and alternating current.

The current intensity indicates the number of electrons that will circulate through a conductor section during a specific time.

Electrical circuits can be open or closed. In open circuits, the electrons flowing are stopped for any reason, for example, an interrupter. On the other hand, an electrical circuit is called a closed circuit when the current can flow around a closed loop.

## What Are the Components of an Electrical Circuit?

The primary electric components that electrical circuits include are the following:

• Generator: The electric generator is the element in charge of generating the electric current by maintaining a potential difference between the ends of the circuit. For example, a battery or a photovoltaic panel.

• Conductor: the current conductor is where the electrons that have driven the electrical generator move. The material used must be electrically conductive. The most conductive elements in the periodic table are silver, copper, and gold.

• Resistors: resistors are elements that oppose the passage of electric current. According to Joule's law, they are the elements of the circuit that lose more useful energy in the form of heat.

• Receptors: Receptors convert electricity into another type of energy. Light bulbs and electric motors are examples of receivers.

• Control elements: the function of these elements is to cut or direct the flow of current within the circuit. Some examples are pushbuttons, switches, and switches.

• Capacitors: A capacitor is an element with the ability to store electrical energy and that it can later release.

All these elements must be adequately protected using electrical insulators to prevent damage, such as short circuits.

Circuit diagrams represent these circuit elements using standardized electronic symbols. Be can draw any kind of electrical circuit by connecting wires to these symbols.

In some circuits, protection elements are used to avoid problems derived from an overvoltage, among others.

Resistors, capacitors, inductors, and other circuit components can be connected in parallel or connected in series.

In series circuits, the current intensity is identical in all elements. However, in parallel circuits in which a current is flowing, the currents add up.

## What Are the Primary Laws of Electrical Circuits?

Some laws apply to all electrical circuits. These include:

• Kirchhoff's law of current (Kirchhoff's first law): The algebraic sum of the electrical currents that enter and leave any node in an electrical circuit is zero at any point or junction.

• Kirchhoff's law of tension (Kirchhoff's second law): In any electrical network, the algebraic sum of all electromotive forces and the algebraic sum of all voltage jumps are the same.

• Ohm's law: electrical resistance during the electric current passing, between the extremes of their potential difference, is directly proportional to the intensity of the opposition to go through.

• Norton's theorem: Any linear circuit with only voltage and current sources and resistors, if points A and B are available, is electrically equivalent to a single current source Iand a single resistor R parallel to it.

• Thévenin's theorem refers to any linear circuit with only voltage and current sources and resistors. If points A and B are available, they are electrically equivalent to a single voltage source V and a single resistor R connected in series.

• Overlap theorem: it refers to a linear circuit with more than one independent source. In this case, the effect of all sources on an impedance is the sum of the impact of each source, replacing other voltage sources with a short circuit and replacing all other current sources with an open circuit.

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Published: September 10, 2021
Last review: September 10, 2021