Sensitivity of a potentiometer can be increased by:A) Increasing the emf of the cell.B) Increasing the length of the potentiometer.C) Decreasing the length of the potentiometer wire.D) None of these.

The sensitivity of a potentiometer can be increased by option B) Increasing the length of the potentiometer.

A potentiometer is a device used to measure electrical potential difference (voltage) in a circuit. It consists of a uniform resistance wire, a sliding contact called the "jockey," and a galvanometer (a sensitive current-measuring device). The length of the wire determines the range of the potentiometer, while the jockey position determines the specific potential difference being measured.

By increasing the length of the potentiometer wire, the overall resistance of the potentiometer increases. This results in a larger potential difference across the potentiometer, allowing for more precise voltage measurements. As a result, the sensitivity of the potentiometer is increased.

Therefore, the correct answer is B) Increasing the length of the potentiometer.