Question

$\text{Statement}1$: A potentiometer is preferred over a voltmeter for the measurement of e.m.f. of a cell.
$\text{Statement}2$: A potentiometer is preferred, as it does not draw any current from the cell.

• A. $\text{Statement}1$ is True, $\text{Statement}2$ is True; $\text{Statement}2$ is a correct explanation for $\text{Statement}1$.
• B. $\text{Statement}1$ is True, $\text{Statement}2$ is True; $\text{Statement}2$ is not a correct explanation for $\text{Statement}1$.
• C. $\text{Statement}1$ is True, $\text{Statement}2$ is False.
• D. $\text{Statement}1$ is False, $\text{Statement}2$ is True.

Answer 1

The correct option is A $\text{Statement}1$ is True, $\text{Statement}2$ is True; $\text{Statement}2$ is a correct explanation for $\text{Statement}1$.

In a balanced condition, the potentiometer does not draw any current, and hence does not disturb the circuit, but voltmeter draws some amount of current from the main circuit.

Hence, option $\left(a\right)$ is correct.

Key concept- A potentiometer is an ideal voltmeter because it does not draw any current from circuit, at the balance point.