Final answer:
The potentiometer measures the voltage of the cell.
Step-by-step explanation:
The potentiometer measures the Voltage of the cell.
A potentiometer is a null measurement device for measuring voltages. It is a variable resistor connected in series with the unknown emf. By making contact at varying locations along the wire, a variable potential can be obtained. The voltages are measured using a galvanometer.
Therefore, the correct option is Voltage.