ALTSM 22-2 Q-15

Dear student,

By using potentiometer, we wish to calculte the voltage of the cell used by finding the null point by sliding the jockey along the potentiometer wire. Then we could find two lengths of the potentiometer for which the respective cells have null point and thus compare them. To be able to find such a null point, the potential difference across the whole potentiometer wire should be greater than or equal to the voltage of battery with higher voltage, so that a null point could be obtained at some point along the length of potentiometer wire for each of the battery.

Hence correct answer is option 2.