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Electromotive Force
In electromagnetism and electronics, electromotive force (also electromotance, abbreviated emf, denoted \mathcal) is an energy transfer to an electric circuit per unit of electric charge, measured in volts. Devices called electrical ''transducers'' provide an emf by Energy transformation, converting other forms of energy into electrical energy. Other types of electrical equipment also produce an emf, such as Battery (electricity), batteries, which convert chemical energy, and Electric generator, generators, which convert mechanical energy. This energy conversion is achieved by Force, physical forces applying Work (physics), physical work on electric charges. However, electromotive force itself is not a physical force, and ISO/International Electrotechnical Commission, IEC standards have deprecated the term in favor of source voltage or source tension instead (denoted U_s). An Hydraulic analogy, electronic–hydraulic analogy may view emf as the mechanical work done to water by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetism
In physics, electromagnetism is an interaction that occurs between particles with electric charge via electromagnetic fields. The electromagnetic force is one of the four fundamental forces of nature. It is the dominant force in the interactions of atoms and molecules. Electromagnetism can be thought of as a combination of electrostatics and magnetism, which are distinct but closely intertwined phenomena. Electromagnetic forces occur between any two charged particles. Electric forces cause an attraction between particles with opposite charges and repulsion between particles with the same charge, while magnetism is an interaction that occurs between charged particles in relative motion. These two forces are described in terms of electromagnetic fields. Macroscopic charged objects are described in terms of Coulomb's law for electricity and Ampère's force law for magnetism; the Lorentz force describes microscopic charged particles. The electromagnetic force is responsible for ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Analogy
Electronic–hydraulic analogies are the representation of electronic circuits by hydraulic circuits. Since electric current is invisible and the processes in play in electronics are often difficult to demonstrate, the various electronic components are represented by hydraulic equivalents. Electricity (as well as heat current, heat) was originally understood to be a kind of fluid, and the names of certain electric quantities (such as current) are derived from hydraulic equivalents. The ''electronic–hydraulic analogy'' (derisively referred to as the ''drain-pipe theory'' by Oliver Lodge) is the most widely used analogy for "electron fluid" in a metal Electrical conductor, conductor. As with all analogies, it demands an intuitive and competent understanding of the baseline paradigms (electronics and hydraulics), and in the case of the hydraulic analogy for electronics, students often have an inadequate knowledge of hydraulics. The analogy may also be reversed to explain or mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Circuit
An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or Conductive trace, traces through which electric current can flow. It is a type of electrical circuit. For a circuit to be referred to as ''electronic'', rather than ''electrical'', generally at least one active component must be present. The combination of components and wires allows various simple and complex operations to be performed: signals can be amplified, computations can be performed, and data can be moved from one place to another. Circuits can be constructed of discrete components connected by individual pieces of wire, but today it is much more common to create interconnections by photolithographic techniques on a laminated Substrate (semiconductor), substrate (a printed circuit board or PCB) and solder the components to these interconnections to create a finished circuit. In an integrated circuit or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Current
An electric current is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is defined as the net rate of flow of electric charge through a surface. The moving particles are called charge carriers, which may be one of several types of particles, depending on the Electrical conductor, conductor. In electric circuits the charge carriers are often electrons moving through a wire. In semiconductors they can be electrons or Electron hole, holes. In an Electrolyte#Electrochemistry, electrolyte the charge carriers are ions, while in Plasma (physics), plasma, an Ionization, ionized gas, they are ions and electrons. In the International System of Units (SI), electric current is expressed in Unit of measurement, units of ampere (sometimes called an "amp", symbol A), which is equivalent to one coulomb per second. The ampere is an SI base unit and electric current is a ISQ base quantity, base quantity in the International System of Qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-circuit Voltage
Open-circuit voltage (abbreviated as OCV or VOC) is the voltage, difference of electrical potential between two Terminal (electronics), terminals of an electronic device when disconnected from any Electric Circuit, circuit. There is no External electric load, external load connected. No external electric current flows between the terminals. Alternatively, the open-circuit voltage may be thought of as the voltage that must be applied to a solar cell or a Electric battery, battery to stop the current. It is sometimes given the symbol Voc. In network analysis (electrical circuits), network analysis this voltage is also known as the Thévenin's theorem, Thévenin voltage. The open-circuit voltages of batteries and solar cells are often quoted under particular conditions (state-of-charge, illumination, temperature, etc.). The potential difference mentioned for batteries and cells is usually the open-circuit voltage. The value of the open-circuit voltage of a transducer equals its e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thévenin's Theorem
As originally stated in terms of direct-current resistance (electricity), resistive circuits only, Thévenin's theorem states that ''"Any linear circuit, linear electrical network containing only voltage source, voltage sources, current source, current sources and resistance (electricity), resistances can be replaced at terminals by an equivalent combination of a voltage source in a series and parallel circuit, series connection with a resistance ."'' * The equivalent voltage is the voltage obtained at terminals of the network with terminals open-circuit voltage, open circuited. * The equivalent resistance is the resistance that the circuit between terminals and would have if all ideal voltage sources in the circuit were replaced by a short circuit and all ideal current sources were replaced by an open circuit (i.e., the sources are set to provide zero voltages and currents). * If terminals and are connected to one another (short), then the current flowing from and wil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal (electronics)
A terminal is the point at which a electrical conductor, conductor from a electrical component, component, device or electrical network, network comes to an end. ''Terminal'' may also refer to an electrical connector at this endpoint, acting as the reusable interface to a conductor and creating a point where external electronic circuit, circuits can be connected. A terminal may simply be the end of a wire or it may be fitted with a Electrical connector, connector or fastener. In network analysis (electrical circuits), network analysis, ''terminal'' means a point at which connections can be made to a network in theory and does not necessarily refer to any physical object. In this context, especially in older documents, it is sometimes called a pole. On circuit diagrams, terminals for external connections are denoted by empty circles. They are distinguished from node (circuits), nodes or Electrical junctions, junctions which are entirely internal to the circuit and are denoted by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up quark, up and down quark, down quarks. Electrons are extremely lightweight particles that orbit the positively charged atomic nucleus, nucleus of atoms. Their negative charge is balanced by the positive charge of protons in the nucleus, giving atoms their overall electric charge#Charge neutrality, neutral charge. Ordinary matter is composed of atoms, each consisting of a positively charged nucleus surrounded by a number of orbiting electrons equal to the number of protons. The configuration and energy levels of these orbiting electrons determine the chemical properties of an atom. Electrons are bound to the nucleus to different degrees. The outermost or valence electron, valence electrons are the least tightly bound and are responsible for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elementary Charge
The elementary charge, usually denoted by , is a fundamental physical constant, defined as the electric charge carried by a single proton (+1 ''e'') or, equivalently, the magnitude of the negative electric charge carried by a single electron, which has charge −1 . In SI units, the coulomb is defined such that the value of the elementary charge is exactly or 160.2176634 zeptocoulombs (zC). Since the 2019 revision of the SI, the seven SI base units are defined in terms of seven fundamental physical constants, of which the elementary charge is one. In the centimetre–gram–second system of units (CGS), the corresponding quantity is . Robert A. Millikan and Harvey Fletcher's oil drop experiment first directly measured the magnitude of the elementary charge in 1909, differing from the modern accepted value by just 0.6%. Under assumptions of the then-disputed atomic theory, the elementary charge had also been indirectly inferred to ~3% accuracy from blackb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Work (physics)
In science, work is the energy transferred to or from an Physical object, object via the application of force along a Displacement (vector), displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the Product (mathematics), product of the force strength and the distance traveled. A force is said to do ''positive work'' if it has a component in the direction of the displacement of the point of application. A force does ''negative work'' if it has a component opposite to the direction of the displacement at the point of application of the force. For example, when a ball is held above the ground and then dropped, the work done by the gravitational force on the ball as it falls is positive, and is equal to the weight of the ball (a force) multiplied by the distance to the ground (a displacement). If the ball is thrown upwards, the work done by the gravitational force is negative, and is equal to the weight multiplied by the dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Conductor
In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge (electric current) in one or more directions. Materials made of metal are common electrical conductors. The flow of negatively charged electrons generates electric current, positively charged holes, and positive or negative ions in some cases. In order for current to flow within a closed electrical circuit, one charged particle does not need to travel from the component producing the current (the current source) to those consuming it (the loads). Instead, the charged particle simply needs to nudge its neighbor a finite amount, who will nudge ''its'' neighbor, and on and on until a particle is nudged into the consumer, thus powering it. Essentially what is occurring is a long chain of momentum transfer between mobile charge carriers; the Drude model of conduction describes this process more rigorously. This momentum transfer model makes metal an ideal choice f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Induction
Electromagnetic or magnetic induction is the production of an electromotive force, electromotive force (emf) across an electrical conductor in a changing magnetic field. Michael Faraday is generally credited with the discovery of induction in 1831, and James Clerk Maxwell mathematically described it as Faraday's law of induction. Lenz's law describes the direction of the induced field. Faraday's law was later generalized to become the Maxwell–Faraday equation, one of the four Maxwell's equations, Maxwell equations in his theory of electromagnetism. Electromagnetic induction has found many applications, including electrical components such as inductors and transformers, and devices such as electric motors and electric generator, generators. History Electromagnetic induction was discovered by Michael Faraday, published in 1831. It was discovered independently by Joseph Henry in 1832. In Faraday's first experimental demonstration, on August 29, 1831, he wrapped two wires aro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
