Question

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.

Answer 1

Hint: To find the answer for the given question, first we need to know what a potentiometer is and also we need to know the sensitivity of the potentiometer. Then we find the solution why the sensitivity of the potentiometer increases.

Complete answer:
A potentiometer has three terminal resistors with sliding or in rotating which contact in form as an adjustable voltage divider. If there are only two terminals used at one end and the output it acts as a variable resistor or rheostat.
A potentiometer is used to measure the instrument and it is essential a voltage divider is used for measuring an electric potential. It is used to control electrical devices such as a volume control on the audio equipment. Potentiometer can be operated by the mechanism of position transducer.
If we increase the current through the potentiometer then the sensitivity will decrease. The smallest potentiometer difference can be measured using a potentiometer and so it is called sensitivity of potentiometer. Sensitivity of the potentiometer is increased only when increasing the length of the potentiometer wire.
If reducing the current in circuit by the rheostat. The both of the above two methods are used in decreasing the potential gradient and by increasing the resistivity.
Hence, the sensitivity of the potentiometer can be increased by increasing the length of the potentiometer.

So therefore option (B) is correct.

Note: Potentiometer is used to measure the $EMF$. It is a kind of an electrical instrument and also used to compare the $EMFs$ of the different cells and use as a variable resistor in many of the applications. Potentiometers can be classified into two important parameters like resistance and power.