Sun May 13, 2012 By:

what is emf and how it is calculated

Expert Reply
Sun May 13, 2012

Flow of current in a wire is produced and maintained only if 
- potential difference is applied across the ends of a wire.
- a constant potential difference is maintained across the two ends of a wire.

The chemical reactions inside the cell generate a difference in potential between the electrodes.

when no current is drawn from the cell ie the cell is not connected in a closed circuit then the potential difference between the electrodes is called emf of the cell.
It is measured by voltmeter.
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