"Thermal inductance Thermal inductance refers to the phenomenon wherein a thermal change of an object surrounded by a fluid will induce a change in convection currents within that fluid, thus inducing a change in the kinetic energy of the fluid. It is considered the thermal analogue to electrical inductance in system equivalence modeling; its unit is the ""thermal henry"". Thus far, few studies have reported on the inductive phenomenon in the heat-transfer behaviour of a system. In 1946, Bosworth demonstrated that heat flow can have an inductive nature through experiments with a fluidic system. He claimed that the measured transient"
"Siemens (unit) The siemens (symbol: S) is the derived unit of electric conductance, electric susceptance and electric admittance in the International System of Units (SI). Conductance, susceptance, and admittance are the reciprocals of resistance, reactance, and impedance respectively; hence one siemens is redundantly equal to the reciprocal of one ohm, and is also referred to as the ""mho"". The 14th General Conference on Weights and Measures approved the addition of the siemens as a derived unit in 1971. The unit is named after Ernst Werner von Siemens. In English, the same form ""siemens"" is used both for the singular and"
"Admittance In electrical engineering, admittance is a measure of how easily a circuit or device will allow a current to flow. It is defined as the reciprocal of impedance. The SI unit of admittance is the siemens (symbol S); the older, synonymous unit is mho, and its symbol is ℧ (an upside-down uppercase omega Ω). Oliver Heaviside coined the term ""admittance"" in December 1887. Admittance is defined as where Resistance is a measure of the opposition of a circuit to the flow of a steady current, while impedance takes into account not only the resistance but also dynamic effects (known"
"(). Its symbol is usually , and it may be represented by writing its magnitude and phase in the form . However, cartesian complex number representation is often more powerful for circuit analysis purposes. The reciprocal of impedance is admittance, whose SI unit is the siemens, formerly called mho. The term ""impedance"" was coined by Oliver Heaviside in July 1886. Arthur Kennelly was the first to represent impedance with complex numbers in 1893. In addition to resistance as seen in DC circuits, impedance in AC circuits includes the effects of the induction of voltages in conductors by the magnetic fields"
"y – shunt admittance per unit length l – length of line C – capacitance of line Admittance In electrical engineering, admittance is a measure of how easily a circuit or device will allow a current to flow. It is defined as the reciprocal of impedance. The SI unit of admittance is the siemens (symbol S); the older, synonymous unit is mho, and its symbol is ℧ (an upside-down uppercase omega Ω). Oliver Heaviside coined the term ""admittance"" in December 1887. Admittance is defined as where Resistance is a measure of the opposition of a circuit to the flow of"
"blocks it. The inductor is a conductor, usually a coil of wire, that stores energy in a magnetic field in response to the current through it. When the current changes, the magnetic field does too, inducing a voltage between the ends of the conductor. The induced voltage is proportional to the time rate of change of the current. The constant of proportionality is termed the inductance. The unit of inductance is the henry, named after Joseph Henry, a contemporary of Faraday. One henry is the inductance that will induce a potential difference of one volt if the current through it"
"Susceptance In electrical engineering, susceptance (""B"") is the imaginary part of admittance, where the real part is conductance. The inverse of admittance is impedance, where the imaginary part is reactance and the real part is resistance. In SI units, susceptance is measured in siemens. Oliver Heaviside first defined this property in June 1887. The general equation defining admittance is given by where, The admittance (formula_2) is the inverse of the impedance (formula_7) or where Note: The susceptance formula_5 is the imaginary part of the admittance formula_2. The magnitude of admittance is given by: Reactance is defined as the imaginary part"
"of the geometry of the design (e.g. area of the plates and the distance between them) and the permittivity of the dielectric material between the plates of the capacitor. For many dielectric materials, the permittivity and thus the capacitance, is independent of the potential difference between the conductors and the total charge on them. The SI unit of capacitance is the farad (symbol: F), named after the English physicist Michael Faraday. A 1 farad capacitor, when charged with 1 coulomb of electrical charge, has a potential difference of 1 volt between its plates. The reciprocal of capacitance is called elastance."
"to distinguish the symbol ""S"" from the lower-case ""s"" where ""second"" is meant, potentially causing confusion. So, for example, a pentode’s transconductance of 2.2 mS might alternatively be written as or (most common in the 1930s) or 2.2 mA/V. A handwritten ""S"" can also be misread as the frequency space variable ""s"", commonly used in transfer functions. Siemens (unit) The siemens (symbol: S) is the derived unit of electric conductance, electric susceptance and electric admittance in the International System of Units (SI). Conductance, susceptance, and admittance are the reciprocals of resistance, reactance, and impedance respectively; hence one siemens is redundantly"
"susceptance materials are used in susceptors built into microwavable food packaging for their ability to convert microwave radiation into heat. Susceptance In electrical engineering, susceptance (""B"") is the imaginary part of admittance, where the real part is conductance. The inverse of admittance is impedance, where the imaginary part is reactance and the real part is resistance. In SI units, susceptance is measured in siemens. Oliver Heaviside first defined this property in June 1887. The general equation defining admittance is given by where, The admittance (formula_2) is the inverse of the impedance (formula_7) or where Note: The susceptance formula_5 is the"
"may derive valuable and fertile methods."" The SI unit of capacitance is named in his honour: the farad. Albert Einstein kept a picture of Faraday on his study wall, alongside pictures of Isaac Newton and James Clerk Maxwell. Physicist Ernest Rutherford stated, ""When we consider the magnitude and extent of his discoveries and their influence on the progress of science and of industry, there is no honour too great to pay to the memory of Faraday, one of the greatest scientific discoverers of all time."" Michael Faraday was born on 22 September 1791 in Newington Butts, which is now part"
"a bell that could be rung at a distance via an electric wire, 1831) and electric relay (1835). The SI unit of inductance, the henry, is named in his honor. Henry's work on the electromagnetic relay was the basis of the practical electrical telegraph, invented by Samuel F. B. Morse and Sir Charles Wheatstone, separately. Henry was born in Albany, New York, to Scottish immigrants Ann Alexander Henry and William Henry. His parents were poor, and Henry's father died while he was still young. For the rest of his childhood, Henry lived with his grandmother in Galway, New York. He"
"to energy, namely time. In 1843, James Prescott Joule independently discovered the mechanical equivalent in a series of experiments. The most famous of them used the ""Joule apparatus"": a descending weight, attached to a string, caused rotation of a paddle immersed in water, practically insulated from heat transfer. It showed that the gravitational potential energy lost by the weight in descending was equal to the internal energy gained by the water through friction with the paddle. In the International System of Units (SI), the unit of energy is the joule, named after James Prescott Joule. It is a derived unit."
"von Siemens, and his children from second marriage were Hertha von Siemens (1870 - 5 January 1939), married in 1899 to Carl Dietrich Harries, and Carl Friedrich von Siemens. Siemens was an advocate of social democracy, and he hoped that industrial development would not be used in favour of capitalism, stating: He also rejected the claim that science lead to materialism, stating instead: Werner von Siemens Ernst Werner Siemens (von Siemens from 1888; 13 December 1816 – 6 December 1892) was a German inventor and industrialist. Siemens's name has been adopted as the SI unit of electrical conductance, the siemens."
"Transconductance Transconductance (for transfer conductance), also infrequently called mutual conductance, is the electrical characteristic relating the current through the output of a device to the voltage across the input of a device. Conductance is the reciprocal of resistance. Transadmittance (or transfer admittance) is the AC equivalent of transconductance. Transconductance is very often denoted as a conductance, ""g"", with a subscript, m, for ""mutual"". It is defined as follows: For small signal alternating current, the definition is simpler: The SI unit, the siemens, with the symbol, S; 1 siemens = 1 ampere per volt replaced the old unit of conductance, having"
"Ampere The ampere (; symbol: A), often shortened to ""amp"", is the base unit of electric current in the International System of Units (SI). It is named after André-Marie Ampère (1775–1836), French mathematician and physicist, considered the father of electrodynamics. The International System of Units defines the ampere in terms of other base units by measuring the electromagnetic force between electrical conductors carrying electric current. The earlier CGS measurement system had two different definitions of current, one essentially the same as the SI's and the other using electric charge as the base unit, with the unit of charge defined by"
"and its definition, was deprecated in favor of the Avogadro constant and its definition. Based on measurements made through the middle of 2017 which calculated a value for the Avogadro constant of ""N"" = , the redefinition of SI units is planned to take effect on 20 May 2019. The value of the constant will be fixed to exactly . The Avogadro constant is named after the early 19th-century Italian scientist Amedeo Avogadro, who, in 1811, first proposed that the volume of a gas (at a given pressure and temperature) is proportional to the number of atoms or molecules regardless"
"Gauss (unit) The gauss, abbreviated as G or Gs, is the cgs unit of measurement of magnetic flux density (or ""magnetic induction"") (B). It is named after German mathematician and physicist Carl Friedrich Gauss. One gauss is defined as one maxwell per square centimeter. The cgs system has been superseded by the International System of Units (SI), which uses the tesla (symbol T) as the unit of magnetic flux density. One gauss equals 1 tesla (100 μT), so 1 tesla = 10,000 gauss. As with all units whose names are derived from a person's name, the first letter of its"
"power in a given period is equal to zero. Due to its dependence on frequency, magnetic inductance is mainly observable in magnetic circuits which operate at VHF and/or UHF frequencies. The notion of magnetic inductivity is employed in analysis and computation of circuit behavior in the gyrator–capacitor model in a way analogous to inductance in electrical circuits. Magnetic impedance (SI unit: Ω) is the ratio of a sinusoidal magnetic tension formula_11 to a sinusoidal magnetic current formula_12 in a gyrator–capacitor model. Analogous to electrical impedance, magnetic impedance is likewise a complex variable. Magnetic impedance is also called the ""full"" magnetic"
"Typical circuit breakers will provide 16 A. The current drawn by a number of typical appliances are: Ampere The ampere (; symbol: A), often shortened to ""amp"", is the base unit of electric current in the International System of Units (SI). It is named after André-Marie Ampère (1775–1836), French mathematician and physicist, considered the father of electrodynamics. The International System of Units defines the ampere in terms of other base units by measuring the electromagnetic force between electrical conductors carrying electric current. The earlier CGS measurement system had two different definitions of current, one essentially the same as the SI's"
"symbol is uppercase (""G""), but when the unit is spelled out, it should be written in lowercase (""gauss""), unless it begins a sentence. Gauss (unit) The gauss, abbreviated as G or Gs, is the cgs unit of measurement of magnetic flux density (or ""magnetic induction"") (B). It is named after German mathematician and physicist Carl Friedrich Gauss. One gauss is defined as one maxwell per square centimeter. The cgs system has been superseded by the International System of Units (SI), which uses the tesla (symbol T) as the unit of magnetic flux density. One gauss equals 1 tesla (100 μT),"
"Poynting vector In physics, the Poynting vector represents the directional energy flux (the energy transfer per unit area per unit time) of an electromagnetic field. The SI unit of the Poynting vector is the watt per square metre (W/m). It is named after its discoverer John Henry Poynting who first derived it in 1884. Oliver Heaviside also discovered it independently. In Poynting's original paper and in many textbooks, the Poynting vector is defined as where bold letters represent vectors and This expression is often called the ""Abraham form"". The Poynting vector is usually denoted by S or N. In the"
"physicist and mathematician who discovered the principle of the barometer in 1644. The unit's name ""torr"" is written in lower case, while its symbol (""Torr"") is always written with upper-case initial; including in combinations with prefixes and other unit symbols, as in ""mTorr"" (millitorr) or ""Torr⋅L/s"" (torr-litres per second). The symbol (uppercase) should be used with prefix symbols (thus, mTorr and millitorr are correct, but mtorr and milliTorr are not). The torr is sometimes incorrectly denoted by the symbol ""T"", which is the SI symbol for the tesla, the unit measuring the strength of a magnetic field. Although frequently encountered,"
"Conductivity (electrolytic) Conductivity (or specific conductance) of an electrolyte solution is a measure of its ability to conduct electricity. The SI unit of conductivity is siemens per meter (S/m). Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring the ionic content in a solution. For example, the measurement of product conductivity is a typical way to monitor and continuously trend the performance of water purification systems. In many cases, conductivity is linked directly to the total dissolved solids (T.D.S.). High quality deionized water has a conductivity of about 5.5"
"Electrostatic induction Electrostatic induction, also known as ""electrostatic influence"" or simply ""influence"" in Europe and Latin America, is a redistribution of electrical charge in an object, caused by the influence of nearby charges. In the presence of a charged body, an insulated conductor develops a positive charge on one end and a negative charge on the other end. Induction was discovered by British scientist John Canton in 1753 and Swedish professor Johan Carl Wilcke in 1762. Electrostatic generators, such as the Wimshurst machine, the Van de Graaff generator and the electrophorus, use this principle. Due to induction, the electrostatic potential"
"across the inductor's terminals. This is the reason that measurements with a voltmeter across an inductor are often reasonably independent of the placement of the test leads. The volt (symbol: ) is the derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honour of the Italian physicist Alessandro Volta (1745–1827), who invented the voltaic pile, possibly the first chemical battery. A simple analogy for an electric circuit is water flowing in a closed circuit of pipework, driven by a mechanical pump. This can be called a ""water circuit"". Potential difference between two points"
"1 Ω⋅m. Electrical conductivity or specific conductance is the reciprocal of electrical resistivity, and measures a material's ability to conduct an electric current. It is commonly represented by the Greek letter σ (sigma), but κ (kappa) (especially in electrical engineering) or γ (gamma) are also occasionally used. Its SI unit is siemens per metre (S/m). In an ideal case, cross-section and physical composition of the examined material are uniform across the sample, and the electric field and current density are both parallel and constant everywhere. Many resistors and conductors do in fact have a uniform cross section with a uniform"
"(V). Two additional unit conversions for watt can be found using the above equation and Ohm's Law. Where ohm (formula_4) is the SI derived unit of electrical resistance. The ""watt"" is named after the Scottish inventor James Watt. This unit was proposed initially by C. William Siemens in August 1882 in his President's Address to the Fifty-Second Congress of the British Association for the Advancement of Science. Noting that units in the practical system of units were named after leading physicists, Siemens proposed that ""Watt"" might be an appropriate name for a unit of power. Siemens defined the unit consistently"
"stress–energy tensor, shows that the above-given expression for the Poynting vector is unique. Poynting vector In physics, the Poynting vector represents the directional energy flux (the energy transfer per unit area per unit time) of an electromagnetic field. The SI unit of the Poynting vector is the watt per square metre (W/m). It is named after its discoverer John Henry Poynting who first derived it in 1884. Oliver Heaviside also discovered it independently. In Poynting's original paper and in many textbooks, the Poynting vector is defined as where bold letters represent vectors and This expression is often called the ""Abraham"
"Immittance In electrical engineering and acoustics, immittance is a concept combining the impedance and admittance of a system or circuit. The term ""immittance"" was invented by H. W. Bode. It is sometimes convenient to use ""immittance"" to refer to a complex number which may be either the impedance (ratio of voltage to current in electrical circuits, or sound pressure to volume velocity in acoustical systems) or the admittance (ratio of current to voltage, or volume velocity to sound pressure) of a system. In audiology, tympanometry is sometimes called ""immittance testing"". Immittance does not have units since it applies to both"
"Farad The farad (symbol: F) is the SI derived unit of electrical capacitance, the ability of a body to store an electrical charge. It is named after the English physicist Michael Faraday. One farad is defined as the capacitance across which, when charged with one coulomb, there is a potential difference of one volt. Equally, one farad can be described as the capacitance which stores a one-coulomb charge across a potential difference of one volt. The relationship between capacitance, charge and potential difference is linear. For example, if the potential difference across a capacitor is halved, the quantity of charge"
"Elastance Electrical elastance is the inverse of capacitance. The SI unit of elastance is the inverse farad (F). The concept is not widely used by electrical and electronic engineers. The value of capacitors is invariably specified in units of capacitance rather than inverse capacitance. However, it is used in theoretical work in network analysis and has some niche applications at microwave frequencies. The term ""elastance"" was coined by Oliver Heaviside through the analogy of a capacitor as a spring. The term is also used for analogous quantities in some other energy domains. It maps to stiffness in the mechanical domain,"
"He thought that the attraction and repulsion were due to different kinds of fluids. Charles-Augustin de Coulomb Charles-Augustin de Coulomb (; ; 14 June 1736 – 23 August 1806) was a French military engineer and physicist. He is best known for developing what is now known as Coulomb's law, the description of the electrostatic force of attraction and repulsion, but also did important work on friction. The SI unit of electric charge, the coulomb, was named in his honour in 1908. Charles-Augustin de Coulomb was born in Angoulême, Angoumois county, France, to Henry Coulomb, an inspector of the royal demesne"