Question

In the question given below, a statement of Assertion (A) is given followed by a corresponding statement of Reason (R) just below it. Of the statements mark the correct answer.

Assertion (A): Potentiometer is much better than a voltmeter for measuring emf of cell.

Reason (R): A potentiometer draws no current while measuring emf of a cell.

• A. Both 'A' and 'R' are true and 'R' is the correct explanation of 'A'.
• B. Both 'A' and 'R' are true and 'R' is not the correct explanation of 'A'
• C. 'A' is true and 'R' is false
• D. 'A' is false and 'R' is true

Answer 1

The correct option is A Both 'A' and 'R' are true and 'R' is the correct explanation of 'A'.

Because voltmeter draws a small current from the main circuit, where the Potential difference between the two points is to be measured, the reading shown by the voltmeter is not accurate.

But in potentiometer, it draws no current while measuring either emf/Potential difference. So, it is more accurate in measuring the emf.