Question

For measuring voltage of any circuit, potentiometer is preferred to voltmeter because
(A) The potentiometer is cheap and easy to handle
(B) Calibration in the voltmeter is sometimes wrong
(C) The potential draws no current during measurement
(D) Range of voltmeter is not as wide as that of the potentiometer

Answer 1

Hint
Potentiometer is one of the passive electronic devices. It works on a uniform resistance where we are varying the position by sliding through it. Thus we can come to the point why we are using this in measuring voltage.

Complete step by step answer
The voltage is applied to the entire length of the uniform resistance. And we are actually measuring the potential difference between the fixed position and sliding position. Thus it is acting like a voltage divider that can be adjusted.
And the potentiometer measures the voltage drop between two points without taking any current component from the circuit. This specialty of the potentiometer will help to measure the voltage more accurately. This is because we are considering a uniform resistance. And the voltage between the two points will balance induced current.
Using the potentiometer, we can compare the emf of a battery with a standard cell and we can measure the internal resistance of a battery cell. We are using mainly two types of potentiometers. They are rotary and linear potentiometers. The constructional features of them are varied.
For measuring voltage of any circuit, a potentiometer is preferred to voltmeter because the potentiometer will not draw any current during the measurement. Hence it will show more accurate value when measuring.
The answer is option (C).

Note
The sensitivity of the potentiometer can be increased if we increase the length of the potentiometer wire. Thus the resistance per unit voltage will be increased. Thus accuracy is increased.