Electrical sources and internal resistance. Finding the EMF and internal resistance of a cell. A voltmeter and variable resistor. Watch this video to see how the EMF and internal resistance The EMF or electromotive force is the energy supplied by a battery or a cell per coulomb (Q) of charge passing through it. The magnitude of emf is equal to V ( potential difference ) across the cell terminals when there is no current flowing through the circuit.

EMF or electromotive force is equal to the potential difference across the terminals of the cell when no current is present. EMF is the energy provided by a cell or battery per coulomb of charge passing through it and it is measured in volts(V).

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