EMf of a cell
It is defined as the work done by the cell force in moving a unit positive charge inside the cell from the negative to the positive terminal against the potential difference between the cell terminals when no current is drawn from it. i.e. mathematically
EMF of a cell depends upon Nature & concentration of the electrolyte, temperature of the electrolyte, nature of the electrodes. But is independent of size of electrodes, Distance between the electrodes, area of electrodes immersed in the electrolyte & quantity of electrolyte.