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364:, for example, might have 2% efficiency at emitting light yet still be 98% efficient at heating a room (In practice it is nearly 100% efficient at heating a room because the light energy will also be converted to heat eventually, apart from the small fraction that leaves through the windows). An
460:, against the cost of attaining greater efficiency. Efficiency can usually be improved by choosing different components or by redesigning the system. Inefficiency probably produces extra heat within the system, which must be removed if it is to remain within its
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360:: a system that wastes most of its input power but produces exactly what it is meant to is effective but not efficient. The term "efficiency" makes sense only in reference to the wanted effect. A
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used in the electrical grid may have efficiency of more than 99%. Early 19th century transformers were much less efficient, wasting up to a third of the energy passing through them.
417:, devices transfer maximum power to a load when running at 50% electrical efficiency. This occurs when the load resistance (of the device in question) is equal to the internal
319:. Where it is not customary or convenient to represent input and output energy in the same units, efficiency-like quantities have units associated with them. For example, the
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range. In a climate-controlled environment, like a home or office, heat generated by appliances may reduce heating costs or increase air conditioning costs.
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4E - International Energy Agency
Implementing Agreement to promote energy efficiency and standards for electrical products worldwide
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Electric kettle: more than 90% (comparatively little heat energy is lost during the 2 to 3 minutes a kettle takes to boil water).
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of a light source expresses the amount of visible light for a certain amount of power transfer and has the units of
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305:{\displaystyle \mathrm {Efficiency} ={\frac {\mathrm {Useful\ power\ output} }{\mathrm {Total\ power\ input} }}}
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Conversion: Energy efficiency in percent of passive loudspeakers to sensitivity in dB per watt and meter
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resistance of the power source. This is valid only for non-reactive source and load impedances.
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International vocabulary of metrology — Basic and general concepts and associated terms (VIM)
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372:), while drawing 20 watts of power from a power source is 50% efficient. (10/20 × 100 = 50%)
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Load Power
Sources for Peak Efficiency, EDN 1979 October 5
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Efficiency of devices at point of maximum power transfer
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that delivers 10 watts of power to its load (e.g., a
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System for the Peak
Efficiency detection, IEEE TPEL
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16:Useful power output per electrical power consumed
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439:Diagram of efficiency for various types of lamps
448:High efficiency is particularly relevant in
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51:introducing citations to additional sources
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499:Index of electronics articles
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545:quantity of dimension one
425:Efficiency of light bulbs
547:dimensionless quantity"
325:fossil fuel power plant
62:"Electrical efficiency"
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509:Mechanical efficiency
462:operating temperature
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429:Further information:
415:maximum power theorem
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514:Performance per watt
489:Efficient energy use
366:electronic amplifier
327:may be expressed in
317:dimensionless number
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47:improve this article
419:Thevenin equivalent
413:As a result of the
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519:Thermal efficiency
484:Antenna efficiency
468:Impedance bridging
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383:Premium efficiency
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431:Luminous efficacy
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398:steam power plant
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559:. Retrieved
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402:electricity
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370:loudspeaker
141:(η – ήτα).
120:electronics
603:Categories
561:2011-03-22
525:References
444:Discussion
362:light bulb
352:Efficiency
343:per watt.
131:expression
128:fractional
116:efficiency
73:newspapers
454:batteries
321:heat rate
103:July 2024
43:talk page
478:See also
472:signals
450:systems
87:scholar
557:. 2008
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