JEE Main 2012 — Current Electricity Question with Solution
JEE Main 2012 (12 May Online)
Question
It is preferable to measure the e.m.f. of a cell by potentiometer than by a voltmeter because of the following possible reasons.
(i) In case of potentiometer, no current flows through the cell.
(ii) The length of the potentiometer allows greater precision.
(iii) Measurement by the potentiometer is quicker.
(iv) The sensitivity of the galvanometer, when using a potentiometer is not relevant.
Which of these reasons are correct?
Choose an option
Show full solutionCorrect option: C
Correct answer
C(i),(ii)
Step-by-step explanation
To measure the emf of a cell we prefer potentiometer rather than voltmeter because
(i) the length of potentiometer which allows greater precision.
(ii) in case of potentiometer, no current flows through the cell.
(iii) of high sensitivity.
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