Electromotive Force (EMF)
Key points
- EMF is the work done per unit charge, in moving a charge across battery terminals.
- The device (usually a battery) does work on the electric charge being transferred within itself.
- Energy supply to the charge by battery cell.
- EMF is the potential difference across battery terminals when the battery has no internal resistance, and the power provided by the battery per unit current.
Electromotive Force is what batteries use to give charges energy in order to move. It is defined as the work done per unit charge, in moving a charge across battery terminals.
- Measured in Volts.
- In a battery:
- Negative ions go from the negative to the positive terminal, and positive ions go vice versa.
- This requires work to be done, provided by the EMF.
- This process also creates a potential difference.
- Negative ions go from the negative to the positive terminal, and positive ions go vice versa.
- EMF is the potential difference across the battery terminals when the battery has no internal resistance.
- It is also the power provided by the battery per unit current.
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