Electric power - Revision history

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Jmdonev at 03:12, 18 May 2018

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	[[Category:Done ~~2015~~-06-11]]		[[Category:Done 2018-05-18]]
	<onlyinclude>'''Electric power''' is a transfer of [[energy]] over time, just like un-prefixed [[power]], specifically it refers to energy transfer in the form of [[electricity]], sending [[current]] through [[conductor]]s. </onlyinclude>		[[File:Incandescent Light Bulb.png\|thumbnail\|250px\|right\|Figure 1. A typical incandescent light bulb. The filament is the thin wire stretched between the vertical contact wires and held up by two other support wires. The electric power is given by the electric current times the voltage drop across the light bulb.]]
			<onlyinclude>'''Electric power''' is a transfer of [[energy]] over time (just like un-prefixed [[power]]), however, it specifically refers to energy transfer in the form of [[electricity]], sending [[electric current]] through [[conductor]]s. </onlyinclude>

	'''Power = Current x Voltage'''		'''Power = [[Current]] x [[Voltage]]'''

	[[Power]] tools, vacuum cleaners, and wall chargers all have an "[[ampere\|amps]]" rating on them. The [[amperage]] (A) of a normally operating industrial circular saw is 15 A. With this amperage rating, it is possible to determine the total power output of the tool, simply by multiplying the amperage by the [[voltage]] of the current it is drawing. For example, running a 15 A circular saw off of a 120 V [[circuit]] would lead to a power draw of 1800 [[watt]]s (W).		[[Power]] tools, vacuum cleaners, and wall chargers all have an "[[ampere\|amps]]" rating on them. The [[amperage]] (A) of a normally operating industrial circular saw is 15 A. With this amperage rating, it is possible to determine the total power output of the tool, simply by multiplying the amperage by the [[voltage]] of the current it is drawing. For example, running a 15 A circular saw off of a 120 V [[circuit]] would lead to a power draw of 1800 [[watt]]s (W).

	==Power==		==Power==
	Electric power is how fast an electrical component, [[circuit]] or system uses [[energy]].		Electric power is how fast an electrical component, [[electric circuit]] or system uses [[energy]].

	*Power units are the [[Watt]] (W), 1 watt is equivalent to 1 [[Joule]]/[[second]] (J/s).		*Power units are the [[Watt]] (W), 1 watt is equivalent to 1 [[Joule]]/[[second]] (J/s).

	The following relationship emerges between power, [[current]] and applied [[voltage]].<~~br /~~>		The following relationship emerges between power, [[current]] and applied [[voltage]]:
	''P=IV~~'' where ''~~P'' is the power, ''I'' is the circuit current and ''V'' is the ~~applied~~ voltage.
	*With the help of [[Ohm's law]] the power equation can be manipulated to be put in terms of different variables as described in the table below.<ref name=B>R.T. Paynter, “Basic Electric Components and Meters,” in ''Introduction to Electricity'', 1rst ed. NJ: Prentice-Hall, 2011, ch. 4, sec. 4.2, pp. 144-154.</ref>		<math>P=IV</math>

			Where <math>P</math> is the power, <math>I</math> is the circuit current and <math>V</math> is the voltage change across the component. With the help of [[Ohm's law]] the power equation can be manipulated to be put in terms of different variables as described in the table below.<ref name=B>R.T. Paynter, “Basic Electric Components and Meters,” in ''Introduction to Electricity'', 1rst ed. NJ: Prentice-Hall, 2011, ch. 4, sec. 4.2, pp. 144-154.</ref>
	{\| class="wikitable"		{\| class="wikitable"
	\|-		\|-
	! In terms of !! Formula		! In terms of !! Formula
	\|-		\|-
	\| circuit current and applied voltage \|\| ''P=IV''		\| circuit current and applied voltage \|\| <math>P=IV</math>
	\|-		\|-
	\| circuit current and circuit [[resistance]] \|\| ''P=I~~<sup>2~~</~~sup~~>~~R''~~		\| circuit current and circuit [[resistance]] \|\| <math>P=I^2R</math>
	\|-		\|-
	\| applied voltage and resistance \|\| ''P=V~~<sup>~~2</~~sup~~>~~/R''~~		\| applied voltage and resistance \|\| <math>P=\frac{V^2}{R}</math>
	\|}		\|}

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	===Power rating===		===Power rating===
	The power rating is the maximum rate at which an electronic device (for example a [[transducer]]) can convert energy into [[energy#Types of energy\|some other form]], similar to [[ampacity]] for electric current. Any device which is capable of converting one form of energy to another is referred to as a transducer. For example, resistors have the ability to absorb energy and transform it into heat~~, the~~ rate at which it absorbs energy must be equal to the rate at which it dissipates heat. If the rate at which the resistor absorbs heat is exceeded the resistor will melt, and be destroyed. The power rating for the resistor thus describes its ability to dissipate heat.		The power rating is the maximum rate at which an electronic device (for example a [[transducer]]) can convert energy into [[energy#Types of energy\|some other form]], similar to [[ampacity]] for electric current. Any device which is capable of converting one form of energy to another is referred to as a transducer. For example, resistors have the ability to absorb energy and transform it into heat. The rate at which it absorbs energy must be equal to the rate at which it dissipates heat. If the rate at which the resistor absorbs heat is exceeded the resistor will melt, and be destroyed. The power rating for the resistor thus describes its ability to dissipate heat.

	===Power efficiency===		===Power efficiency===
	The power [[efficiency]] of a device is a measure of how well that device converts [[electricity]] into [[work]]. [[Electric motor]]s have extremely high power efficiency, usually over 90%, and often exceeding 96%. This is in stark contrast to [[internal combustion engine]]s, which have an efficiency of between 25% and 35%. This discrepancy in efficiency is why [[electric vehicle]]s achieve such high [[miles per gallon gasoline equivalent\|MPGe]] ratings. This is also why electricity is considered to be [[energy quality\|higher quality energy]].		The power [[efficiency]] of a device is a measure of how well that device converts [[electricity]] into [[work]]. [[Electric motor]]s have extremely high power efficiency, usually over 90%, and often exceeding 96%. This is in stark contrast to [[internal combustion engine]]s, which have an efficiency of between 25% and 35%. This discrepancy in efficiency is why [[electric vehicle]]s achieve such high [[miles per gallon gasoline equivalent\|MPGe]] ratings. This is also why electricity is considered to be [[energy quality\|higher quality energy]].

	Power efficiency cannot exceed 100% because energy cannot be created or destroyed as stated in the [[~~Energy#The first~~ law of thermodynamics:\|~~First law of thermodynamics~~]].		Power efficiency cannot exceed 100% because energy cannot be created or destroyed as stated in the [[First law of thermodynamics]].

			== For Further Reading ==
			For further information please see the related pages below:
			*[[Direct current]]
			*[[Electricity]]
			*[[Electrical grid]]
			*[[Electric generator]]
			* Or explore a [[Special:Random\| random page!]]

	==References==		==References==
	{{reflist}}		{{reflist}}
	[[Category:Uploaded]]		[[Category:Uploaded]]

J.williams: 1 revision imported

2015-08-26T21:30:42Z

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J.williams at 22:43, 11 August 2015

2015-08-11T22:43:54Z

New page

[[Category:Done 2015-06-11]]
<onlyinclude>'''Electric power''' is a transfer of [[energy]] over time, just like un-prefixed [[power]], specifically it refers to energy transfer in the form of [[electricity]], sending [[current]] through [[conductor]]s. </onlyinclude>

'''Power = Current x Voltage'''

[[Power]] tools, vacuum cleaners, and wall chargers all have an "[[ampere|amps]]" rating on them. The [[amperage]] (A) of a normally operating industrial circular saw is 15 A. With this amperage rating, it is possible to determine the total power output of the tool, simply by multiplying the amperage by the [[voltage]] of the current it is drawing. For example, running a 15 A circular saw off of a 120 V [[circuit]] would lead to a power draw of 1800 [[watt]]s (W).

==Power==
Electric power is how fast an electrical component, [[circuit]] or system uses [[energy]].

*Power units are the [[Watt]] (W), 1 watt is equivalent to 1 [[Joule]]/[[second]] (J/s).

The following relationship emerges between power, [[current]] and applied [[voltage]]. 
''P=IV'' where ''P'' is the power, ''I'' is the circuit current and ''V'' is the applied voltage.
*With the help of [[Ohm's law]] the power equation can be manipulated to be put in terms of different variables as described in the table below.<ref name=B>R.T. Paynter, “Basic Electric Components and Meters,” in ''Introduction to Electricity'', 1rst ed. NJ: Prentice-Hall, 2011, ch. 4, sec. 4.2, pp. 144-154.</ref>
{| class="wikitable"
|-
! In terms of !! Formula
|-
| circuit current and applied voltage || ''P=IV''
|-
| circuit current and circuit [[resistance]] || ''P=I2R''
|-
| applied voltage and resistance || ''P=V2/R''
|}

The [[#Power rating|power rating]] is crucial in electrical applications especially to [[transducer]]s.

===Power rating===
The power rating is the maximum rate at which an electronic device (for example a [[transducer]]) can convert energy into [[energy#Types of energy|some other form]], similar to [[ampacity]] for electric current. Any device which is capable of converting one form of energy to another is referred to as a transducer. For example, resistors have the ability to absorb energy and transform it into heat, the rate at which it absorbs energy must be equal to the rate at which it dissipates heat. If the rate at which the resistor absorbs heat is exceeded the resistor will melt, and be destroyed. The power rating for the resistor thus describes its ability to dissipate heat.

===Power efficiency===
The power [[efficiency]] of a device is a measure of how well that device converts [[electricity]] into [[work]]. [[Electric motor]]s have extremely high power efficiency, usually over 90%, and often exceeding 96%. This is in stark contrast to [[internal combustion engine]]s, which have an efficiency of between 25% and 35%. This discrepancy in efficiency is why [[electric vehicle]]s achieve such high [[miles per gallon gasoline equivalent|MPGe]] ratings. This is also why electricity is considered to be [[energy quality|higher quality energy]].

Power efficiency cannot exceed 100% because energy cannot be created or destroyed as stated in the [[Energy#The first law of thermodynamics:|First law of thermodynamics]].

==References==
{{reflist}}
[[Category:Uploaded]]