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The "two-fluid" theory of electricity, created by Charles François de Cisternay du Fay, postulated that electricity was the interaction between two electrical 'fluids.' An alternate simpler theory was proposed by Benjamin Franklin, called the unitary, or one-fluid, theory of electricity. This theory claimed that electricity was really one ...
The mechanical power needed to assist in this production is provided by a number of different sources. These sources are called prime movers, and include diesel, petrol and natural gas engines. Coal, oil, natural gas, biomass and nuclear energy are energy sources that are used to heat water to produce super-heated steam. Non-mechanical prime ...
Electricity (as well as 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 ) [ 1 ] is the most widely used analogy for "electron fluid" in ...
In optics, optical power (also referred to as dioptric power, refractive power, focusing power, or convergence power) is the degree to which a lens, mirror, or other optical system converges or diverges light. It is equal to the reciprocal of the focal length of the device: P = 1/f. [1] High optical power corresponds to short focal length.
Electricity generation is the process of generating electric power from sources of primary energy.For utilities in the electric power industry, it is the stage prior to its delivery (transmission, distribution, etc.) to end users or its storage, using for example, the pumped-storage method.
Electricity is usually sold by the kilowatt hour (3.6 MJ) which is the product of power in kilowatts multiplied by running time in hours. Electric utilities measure power using electricity meters , which keep a running total of the electric energy delivered to a customer.
Electric power is the rate of transfer of electrical energy within a circuit.Its SI unit is the watt, the general unit of power, defined as one joule per second.Standard prefixes apply to watts as with other SI units: thousands, millions and billions of watts are called kilowatts, megawatts and gigawatts respectively.
The optical power of corrective lenses is measured in diopters, a value equal to the reciprocal of the focal length measured in metres; with a positive focal length corresponding to a converging lens and a negative focal length corresponding to a diverging lens. For lenses that correct for astigmatism as well, three numbers are given: one for ...