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Kirchhoff's Laws (other)
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Kirchhoff's laws, named after Gustav Kirchhoff, may refer to: * Kirchhoff's circuit laws in electrical engineering * Kirchhoff's law of thermal radiation * Kirchhoff equations in fluid dynamics * Kirchhoff's three laws of spectroscopy * Kirchhoff's law of thermochemistry See also * Kerckhoffs's principle, of Auguste Kerckhoffs * List of scientific laws named after people * Ohm's law Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gustav Kirchhoff
Gustav Robert Kirchhoff (; 12 March 1824 – 17 October 1887) was a German physicist who contributed to the fundamental understanding of electrical circuits, spectroscopy, and the emission of black-body radiation by heated objects. He coined the term black-body radiation in 1862. Several different sets of concepts are named "Kirchhoff's laws" after him, concerning such diverse subjects as black-body radiation and spectroscopy, electrical circuits, and thermochemistry. The Bunsen–Kirchhoff Award for spectroscopy is named after him and his colleague, Robert Bunsen. Life and work Gustav Kirchhoff was born on 12 March 1824 in Königsberg, Prussia, the son of Friedrich Kirchhoff, a lawyer, and Johanna Henriette Wittke. His family were Lutherans in the Evangelical Church of Prussia. He graduated from the Albertus University of Königsberg in 1847 where he attended the mathematico-physical seminar directed by Carl Gustav Jacob Jacobi, Franz Ernst Neumann and Friedrich Julius Ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirchhoff's Circuit Laws
Kirchhoff's circuit laws are two equalities that deal with the current and potential difference (commonly known as voltage) in the lumped element model of electrical circuits. They were first described in 1845 by German physicist Gustav Kirchhoff. This generalized the work of Georg Ohm and preceded the work of James Clerk Maxwell. Widely used in electrical engineering, they are also called Kirchhoff's rules or simply Kirchhoff's laws. These laws can be applied in time and frequency domains and form the basis for network analysis. Both of Kirchhoff's laws can be understood as corollaries of Maxwell's equations in the low-frequency limit. They are accurate for DC circuits, and for AC circuits at frequencies where the wavelengths of electromagnetic radiation are very large compared to the circuits. Kirchhoff's current law This law, also called Kirchhoff's first law, or Kirchhoff's junction rule, states that, for any node (junction) in an electrical circuit, the sum of currents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirchhoff's Law Of Thermal Radiation
In heat transfer, Kirchhoff's law of thermal radiation refers to wavelength-specific radiative emission and absorption by a material body in thermodynamic equilibrium, including radiative exchange equilibrium. It is a special case of Onsager reciprocal relations as a consequence of the time reversibility of microscopic dynamics, also known as microscopic reversibility. A body at temperature radiates electromagnetic energy. A perfect black body in thermodynamic equilibrium absorbs all light that strikes it, and radiates energy according to a unique law of radiative emissive power for temperature (Stefan–Boltzmann law), universal for all perfect black bodies. Kirchhoff's law states that: Here, the dimensionless coefficient of absorption (or the absorptivity) is the fraction of incident light (power) that is absorbed by the body when it is radiating and absorbing in thermodynamic equilibrium. In slightly different terms, the emissive power of an arbitrary opaque body ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirchhoff Equations
In fluid dynamics, the Kirchhoff equations, named after Gustav Kirchhoff, describe the motion of a rigid body in an ideal fluid In physics, a perfect fluid is a fluid that can be completely characterized by its rest frame mass density \rho_m and ''isotropic'' pressure ''p''. Real fluids are "sticky" and contain (and conduct) heat. Perfect fluids are idealized models in whi .... : \begin & = \times \vec \omega + \times \vec v + \vec Q_h + \vec Q, \\ 0pt & = \times \vec \omega + \vec F_h + \vec F, \\ 0ptT & = \left( \vec \omega^T \tilde I \vec \omega + m v^2 \right) \\ 0pt\vec Q_h & =-\int p \vec x \times \hat n \, d\sigma, \\ 0pt\vec F_h & =-\int p \hat n \, d\sigma \end where \vec \omega and \vec v are the angular and linear velocity vectors at the point \vec x, respectively; \tilde I is the moment of inertia tensor, m is the body's mass; \hat n is a unit normal to the surface of the body at the point \vec x; p is a pressure at this point; \vec Q_h and \vec F_h are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerckhoffs's Principle
Kerckhoffs's principle (also called Kerckhoffs's desideratum, assumption, axiom, doctrine or law) of cryptography was stated by Dutch-born cryptographer Auguste Kerckhoffs in the 19th century. The principle holds that a cryptosystem should be secure, even if everything about the system, except the key, is public knowledge. This concept is widely embraced by cryptographers, in contrast to security through obscurity, which is not. Kerckhoffs's principle was phrased by American mathematician Claude Shannon as "the enemy knows the system", i.e., "one ought to design systems under the assumption that the enemy will immediately gain full familiarity with them". In that form, it is called Shannon's maxim. Another formulation by American researcher and professor Steven M. Bellovin is: In other words — design your system assuming that your opponents know it in detail. (A former official at NSA's National Computer Security Center told me that the standard assumption there was that ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Scientific Laws Named After People
This is a list of scientific laws named after people ( eponymous laws). For other lists of eponyms, see eponym. See also * Eponym * Fields of science * List of eponymous laws (overlaps with this list but includes non-scientific laws such as Murphy's law) * List of legislation named for a person * List of laws in science * Lists of etymologies * Scientific constants named after people * Scientific phenomena named after people * Stigler's law of eponymy Further reading * {{cite book, title=A dictionary of named effects and laws in chemistry, physics, and mathematics, last1=Ballentyne, first1=D. W. G., last2=Lovett, first2=D. R., publisher=Chapman and Hall, year=1980, isbn=978-0-412-22380-8, edition=4th scientific laws named after people Scientific laws Scientific laws or laws of science are statements, based on repeated experiments or observations, that describe or predict a range of natural phenomena. The term ''law'' has diverse usage in many cases (approximate, accu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
