Electrical element
Electrical elements, also known as circuit elements, are fundamental components in electrical circuits, connected by wires to form closed loops. There are two main categories: active elements, like batteries and generators, which can generate energy, and passive elements, such as resistors, which do not generate energy but instead dissipate it. The flow of electric current in these circuits is driven by the movement of charged particles, primarily electrons, which can be influenced by electrostatic forces. In conductive materials, free electrons can move through the atomic structure, creating a flow of electricity.
These electrical elements can be either real, measurable devices used in actual systems, or ideal, theoretical models used for simulation. Common passive elements include resistors, capacitors, and inductors. Resistors limit current and can help manage voltage levels, while capacitors store electrical energy and regulate voltage fluctuations. Inductors, on the other hand, create magnetic fields and resist changes in current flow. Together, these components play crucial roles in the functionality of various electrical devices and appliances, balancing the use of large and small currents for efficient operation.
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Electrical element
Electrical elements, or circuit elements, are devices connected by wires in closed paths, or complete loops. Both active and passive elements exist. Active elements, such as batteries and generators, are capable of generating energy. Passive elements, such as resistors, cannot generate energy and often use up energy. Many electric devices have both types of elements.
Electricity
A current of electricity is the flow of electric charge. Charge is a measurable property of matter and can be either positive or negative. Electricity originates at the atomic level with electrons (negatively charged) and protons (positively charged). Opposites attract, and likes repel; this is known as electrostatic force, or Coulomb's law. Charges that are close together will have greater electrostatic force than those farther away from one another. Electrons repel other electrons but are attracted to protons.
To create electricity, an electron must be freed from an atom and forced elsewhere. Valence electrons, electrons in the outermost layer of an atom, are easiest to free. In a conductive wire—for example copper—an electron can be removed from an atom using electrostatic force. This free electron is affected by the charges of other atoms and is pulled into another atom's valence layer. Millions of other copper atoms in the wire go through the same cycle, gaining and losing electrons. The movement of these free electrons is the flow of electric current. Conductivity refers to the ease of freeing up electrons. Insulators are elements with low conductivity. Because they prevent the flow of electrons, insulators can be used to control the current.
Circuits, as their name suggests, are circular paths. An active element such as a battery provides the force to move electrons through these paths and provides power for electrical devices. This force is called voltage. The electrons must have a complete circuit to travel and eventually return to the source. Most circuits have an off switch, which opens a gap in the circuit and halts the electron movement, turning off the current.
Batteries have positive and negative terminals, indicating the charges located there. Batteries connect to the circuit so they can simultaneously push electrons out from the negative terminal and pull them back to the positive terminal. Electricity and electrical appliances use large currents for power. Electronics use tiny currents to power things. These coexist in many modern appliances, such as when a small current powers the electronic components of an electric washing machine. The electronic component controls the large current and the actions it powers, such as agitation and spinning.
Circuit Elements
Electrical devices are either real or ideal. Real devices are parts of the hardware of a real system and can be measured. Ideal devices are models or mathematically defined elements, such as simulations. They are theoretical and therefore perfect. Idealized electrical elements include resistors, capacitors, and inductors, which are passive elements.
Resistors, as the name suggests, provide electrical resistance, which limits the electron current through a circuit and remains steady. Resistors do not generate power; they are passive components but often are paired with active components. In addition to limiting current, they may also divide voltages. Resistors are made of conductive materials such as carbon, metal, or metal-oxide film, and may be covered by or wrapped around an insulating material. As an example, resistors limit the current flowing into a light-emitting diode (LED), protecting it so it does not blow up. To limit the current flow, the minimum current needed to light up the LED must be known, as well as the maximum current it can handle. A resistor must keep the current within the acceptable range. A voltage divider is another type of resistor, which can take a large voltage and convert it to a smaller voltage output.
Capacitors have two terminals and are able to store energy like a battery. They can store energy locally, suppress voltage spikes, and filter complex signals. Capacitors are sandwiches of an insulating material called a dielectric between two metal plates. A dielectric can be ceramic, glass, plastic, rubber, or any other insulating material. The conductive plates may be aluminum, silver, or other metals connected to a terminal wire. The current cannot bridge the gap made by the dielectric, so one plate captures and holds the free electrons and becomes negatively charged. The other plate becomes positively charged because the negative charge on the first plate pushes away the like charge. In keeping with Coulomb's law, the charges of the plates now attract each other, but they remain stationary because the dielectric plate blocks them. This standoff creates an electric field, which can be held by the capacitor. Capacitors have many uses, including regulating power supply. For example, if a power supply voltage drops slightly, the capacitor's charge could be diverted to maintain the proper voltage level.
Inductors are tightly wound coils of wire that resist a change in the flow of electrons. When a current passes through an inductor coil, it creates a magnetic field. The inductor can briefly store some electrical energy. When put into a varying magnetic field, the coil conducts current. Because the wire is an excellent conductor, the coil readily takes the current and builds up a magnetic field. When the current is interrupted (turned off), the magnetic field keeps the current flowing briefly until the field collapses. The capacity of a conductor is decided by the number of coils, the material used for its core, the area or cross-section, and the coil length.
Bibliography
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