# Electromotive Force

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The electromotive force ($\epsilon$) of a source is the energy converted from other forms to electrical per unit charge delivered round a complete circuit.

$\epsilon = \frac{E}{Q}$

, where

• $\epsilon$ is electromotive force (Units: V),
• E is energy converted,
• Q is charge

Difference between electromotive force and potential difference

• Electromotive Force of a source is the ability of the source to generate electrical energy from other forms of energy and supply it to the circuit whereas potential difference across a part of a circuit or device, measures the ability of the device or part of a circuit at converting electrical energy to other forms of energy.
• There will be no potential difference without electromotive force, but electromotive force exists whether a current flows or not.