basic commutator
11Glossary of group theory — A group ( G , •) is a set G closed under a binary operation • satisfying the following 3 axioms:* Associativity : For all a , b and c in G , ( a • b ) • c = a • ( b • c ). * Identity element : There exists an e ∈ G such that for all a in G , e •… …
12Electrical generator — In electricity generation, an electrical generator is a device that converts mechanical energy to electrical energy, generally using electromagnetic induction. The reverse conversion of electrical energy into mechanical energy is done by a motor …
13Baker-Campbell-Hausdorff formula — In mathematics, the Baker Campbell Hausdorff formula is the solution to:Z = log(e^X e^Y),for non commuting X and Y . It is named for Henry Frederick Baker, John Edward Campbell, and Felix Hausdorff. It was first noted in print by Campbell,… …
14British absolute block signalling — The principle of the British absolute block system of railway signalling is to facilitate the safe operation of a railway by preventing more than one train from occupying a defined section of route at the same time. This system is used on double… …
15Representation theory — This article is about the theory of representations of algebraic structures by linear transformations and matrices. For the more general notion of representations throughout mathematics, see representation (mathematics). Representation theory is… …
16electric generator — ▪ instrument Introduction also called dynamo, any machine that converts mechanical energy to electricity for transmission and distribution over power lines to domestic, commercial, and industrial customers. Generators also produce the… …
17Electric generator — U.S. NRC image of a modern steam turbine generator In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge (usually carried by electrons) to flow… …
18Alexander polynomial — In mathematics, the Alexander polynomial is a knot invariant which assigns a polynomial with integer coefficients to each knot type. James Waddell Alexander II discovered this, the first knot polynomial, in 1923. In 1969, John Conway showed a… …
19Armature reaction drop — is the effect of a magnetic field on the distribution of the flux under main poles of a generator. [cite book|title=Basic Electricity |author= A.Van Valkenburgh|year=1993|publisher=Thomson Delmar Learning|url=http://books.google.com/books?vid=ISBN… …
20Physics — (Greek: physis φύσις), in everyday terms, is the science of matter [R. P. Feynman, R. B. Leighton, M. Sands (1963), The Feynman Lectures on Physics , ISBN 0 201 02116 1 Hard cover. p.1 1 Feynman begins with the atomic hypothesis.] and its motion …
