NRJC: /* Formulae */

2024-05-28T10:37:02Z

‎Formulae

NRJC: Created page with "==Key Stage 5== ===Meaning=== '''Electromotive force''' (emf) is the amount of work produced per unit charge by a Power Supply|source..."

2024-05-28T10:36:44Z

Created page with "==Key Stage 5== ===Meaning=== '''Electromotive force''' (emf) is the amount of work produced per unit charge by a Power Supply|source..."

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==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{𝑊}{𝑄}</math>
Where:
*<math>\varepsilon</math> is the '''emf'''
*𝑊 is the [[Work Done|work done]] to move the [[Electrical Charge|charge]]
*𝑄 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>𝑉=𝐸−𝐼𝑟</math>
Where:
*𝑉 is the [[Terminal voltage|terminal voltage]]
*𝐼 is the [[Electrical Current|current]] through between the terminals
*𝑟 is the [[Internal Resistance|internal resistance]] of the [[Power Supply|power supply]]

@@ Line 19: / Line 19: @@
 The [[Terminal Voltage|terminal voltage]] of an [[Electrical Cell|electrical cell]] or [[battery]] is related to '''emf''' by the following formula:
-*<math>𝑉=𝐸−𝐼𝑟</math>
+*<math>𝑉=\varepsilon−𝐼𝑟</math>
 Where:
 *𝑉 is the [[Terminal voltage|terminal voltage]]
 *𝐼 is the [[Electrical Current|current]] through between the terminals
 *𝑟 is the [[Internal Resistance|internal resistance]] of the [[Power Supply|power supply]]

Electromotive Force - Revision history

NRJC: /* Formulae */

NRJC: Created page with "==Key Stage 5== ===Meaning=== '''Electromotive force''' (emf) is the amount of work produced per unit charge by a Power Supply|source..."