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.
