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Created page with "==Key Stage 5== ===Meaning=== '''Electromotive force''' (emf) is the amount of work produced per unit charge by a Power Supply|source..."
==Key Stage 5==
===Meaning===
'''Electromotive force''' (emf) is the amount of [[Work Done|work]] produced per [[unit]] [[Electrical Charge|charge]] by a [[Power Supply|source of electric power]].
===About Electromotive Force (emf)===
*'''Emf''' is given by the symbol <math>\varepsilon</math>
*'''Emf''' is [[measure]]d in [[volt]]s (V).
*'''Emf''' is not actually a force, but a [[Potential Difference|potential difference]] that drives [[Electrical Current|current]] around a [[circuit]].
*In a circuit, the '''emf''' is equal to the [[Potential Difference|potential difference]] across the terminals of the [[Power Supply|power source]] when no [[Electrical Current|current]] is flowing.
*The [[Internal Resistance|internal resistance]] of the [[Power Supply|power source]] causes the terminal [[Potential Difference|voltage]] to be less than the '''emf''' when [[Electrical Current|current]] is flowing.
===Formulae===
The '''electromotive force''' is given by the formula:
*<math>\varepsilon=\frac{π}{π}</math>
Where:
*<math>\varepsilon</math> is the '''emf'''
*π is the [[Work Done|work done]] to move the [[Electrical Charge|charge]]
*π is the [[Electrical Charge|charge]]
The [[Terminal Voltage|terminal voltage]] of an [[Electrical Cell|electrical cell]] or [[battery]] is related to '''emf''' by the following formula:
*<math>π=πΈβπΌπ</math>
Where:
*π is the [[Terminal voltage|terminal voltage]]
*πΌ is the [[Electrical Current|current]] through between the terminals
*π is the [[Internal Resistance|internal resistance]] of the [[Power Supply|power supply]]
===Meaning===
'''Electromotive force''' (emf) is the amount of [[Work Done|work]] produced per [[unit]] [[Electrical Charge|charge]] by a [[Power Supply|source of electric power]].
===About Electromotive Force (emf)===
*'''Emf''' is given by the symbol <math>\varepsilon</math>
*'''Emf''' is [[measure]]d in [[volt]]s (V).
*'''Emf''' is not actually a force, but a [[Potential Difference|potential difference]] that drives [[Electrical Current|current]] around a [[circuit]].
*In a circuit, the '''emf''' is equal to the [[Potential Difference|potential difference]] across the terminals of the [[Power Supply|power source]] when no [[Electrical Current|current]] is flowing.
*The [[Internal Resistance|internal resistance]] of the [[Power Supply|power source]] causes the terminal [[Potential Difference|voltage]] to be less than the '''emf''' when [[Electrical Current|current]] is flowing.
===Formulae===
The '''electromotive force''' is given by the formula:
*<math>\varepsilon=\frac{π}{π}</math>
Where:
*<math>\varepsilon</math> is the '''emf'''
*π is the [[Work Done|work done]] to move the [[Electrical Charge|charge]]
*π is the [[Electrical Charge|charge]]
The [[Terminal Voltage|terminal voltage]] of an [[Electrical Cell|electrical cell]] or [[battery]] is related to '''emf''' by the following formula:
*<math>π=πΈβπΌπ</math>
Where:
*π is the [[Terminal voltage|terminal voltage]]
*πΌ is the [[Electrical Current|current]] through between the terminals
*π is the [[Internal Resistance|internal resistance]] of the [[Power Supply|power supply]]