Voltage Definition in Physics

Voltage Definition in Physics Voltage is a representation of the electric potential energy per unit charge. If a unit of electrical charge were placed in a location, the voltage indicates the potential energy of it at that point. In other words, it is a measurement of the energy contained within an electric field, or an electric circuit, at a given point. It is equal to the work that would have to be done per unit charge against the electric field to move the charge from one point to another. Voltage is a scalar quantity; it does not have direction. Ohms Law says voltage equals current times resistance. Units of Voltage The SI unit of voltage is the volt, such that 1 volt 1 joule/coulomb. It is represented by V. The volt is named after Italian physicist Alessandro Volta who invented a chemical battery. This means that one coulomb of charge will gain one joule of potential energy when it is moved between two locations where the electric potential difference is one volt. For a voltage of 12 between two locations, one coulomb of charge will gain 12 joules of potential energy. A six-volt battery has a potential for one coulomb of charge to gain six joules of potential energy between two locations. A nine-volt battery has a potential for one coulomb of charge to gain nine joules of potential energy. How Voltage Works A more concrete example of voltage from real life is a water tank with a hose extending from the bottom. Water in the tank represents stored charge. It takes work to fill the tank with water. This creates a store of water, as separating charge does in a battery. The more water in the tank, the more pressure there is and the water can exit through the hose with more energy. If there were less water in the tank, it would exit with less energy. This pressure potential is equivalent to voltage. The more water in the tank, the more pressure. The more charge stored in a battery, the more voltage. When you open the hose, the current of water then flows. The pressure in the tank determines how fast it flows out of the hose. Electrical current is measured in Amperes or Amps. The more volts you have, the more amps for the current, same as the more water pressure you have, the faster the water will flow out of the tank. However, the current is also affected by resistance. In the case of the hose, it is how wide the hose is. A wide hose allows more water to pass in less time, while a narrow hose resists the water flow. With an electrical current, there can also be resistance, measured in ohms. Ohms Law says voltage equals current times resistance. V I * R. If you have a 12-volt battery but your resistance is two ohms, your current will be six amps. If the resistance were one ohm, your current would be 12 amps.

Definition and Examples of Diachronic Linguistics

Definition and Examples of Diachronic Linguistics Diachronic linguistics is the study of a language through different periods in history. Diachronic linguistics is one of the two main temporal dimensions of language study identified by Swiss linguist Ferdinand de Saussure in his Course in General Linguistics (1916). The other is synchronic linguistics. The terms diachrony  and synchrony  refer, respectively, to an evolutionary phase of language and to a language state.  In reality, says  Thà ©ophile Obenga, diachronic and synchronic linguistics interlock (Genetic Linguistic Connections of Ancient Egypt and the Rest of Africa, 1996). Observations Diachronic literally means across-time, and it describes any work which maps the shifts and fractures and mutations of languages over the centuries. In gross outline, it is similar to evolutionary biology, which maps the shifts and transformations of rocks. Synchronic literally means with-time, though etymology is misleading here, since Saussures term describes an atemporal linguistics, linguistics which proceeds without time, which abstracts away from the effects of the ages and studies language at a given, frozen moment.(Randy Allen Harris, The Linguistic Wars. Oxford University Press, 1993) Diachronic Studies of Language vs. Synchronic Studies - Diachronic linguistics is  the historical study of language, whereas synchronic linguistics is the geographic study of language. Diachronic linguistics refers to the study of how a language evolves over a period of time. Tracing the development of English from the Old English period  to the twentieth century is a diachronic study. A synchronic study of language is a comparison of languages or dialects- various spoken differences of the same language- used within some defined spatial region and during the same period of time. Determining the regions of the United States in which people currently say pop rather than soda and idea rather than idear are examples of the types of inquiries pertinent to a synchronic study.(Colleen Elaine Donnelly,  Linguistics for Writers. State University of New York Press, 1994)-  Most of Saussures successors accepted the synchronic-diachronic distinction, which still survives robustly in twenty-first-century linguistics. In practice, what this means is that it is accounted a violation of principle or linguistic method to include in the same synchronic analysis evidence related to diachronically different states. So, for example, citing Shakespearean forms would be regarded as inadmissible in support of, say, an analysis of the grammar of Dickens. Saussure is particularly severe in his strictures upon linguists who conflate synchronic and diachronic facts.(Roy Harris, Linguists After Saussure. The Routledge Companion to Semiotics and Linguistics, ed. by Paul Cobley. Routledge, 2001) Diachronic Linguistics and Historical Linguistics   Ã¢â‚¬â€¹Language change is one of the subjects of historical linguistics, the subfield of linguistics that studies language in its historical aspects. Sometimes the term  diachronic linguistics is  used instead of historical linguistics, as a way of referring to the study of language (or languages) at various points in time and at various historical stages. (Adrian Akmajian, Richard A. Demer, Ann K. Farmer, and Robert M. Harnish,  Linguistics: An Introduction to Language and Communication, 5th ed. The MIT Press, 2001)     For many scholars who would describe their field as historical linguistics, one legitimate target of research involves a focus not on change(s) over time but on the synchronic grammatical systems of earlier language stages. This practice can be called (not unrevealingly) old-time synchrony, and it has made its mark in the form of numerous studies providing synchronic analyses of particular syntactic constructions, word-formation processes, (morpho)phonological alternations, and the like for individual earlier (pre-modern or at least early modern) stages of languages. . . . Gaining as much synchronic information as possible about an earlier stage of a language must surely be viewed as a necessary prerequisite for doing serious work on the diachronic development of a language . . .. Nonetheless, pursuing the synchrony of earlier language states solely for the sake of (synchronic) theory-building.., as worthy a goal as it may be, does not count as doing historical linguistics in the literally dia-chronic (through-time) sense that we wish to develop here. At least in a technical sense, then, diachronic linguistics and historical linguistics are not synonymous, because only the latter includes research on old-time synchrony for its own sake, without any focus on language change. (Richard D. Janda and Brian D. Joseph, On Language, Change, and Language Change. The Handbook of Historical Linguistics, ed. by B. D. Joseph and R. D. Janda. Blackwell, 2003)