Which statement concerning the electromotive force (e.m.f.) of a cell is always true?
- AThe e.m.f. is the energy converted from electrical to other forms in the cell.
- BThe e.m.f. is the energy provided by the cell per unit charge passing through it.
- CThe e.m.f. is the potential difference across the internal resistance of the cell.
- DThe e.m.f. is the potential difference across the terminals of the cell.