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?
A$(i), (iii), (iv)$
B$(i), (iii), (iv)$
C$(i), (ii)$
D$(i), (ii), (iii), (iv)$
AIEEE 2012, Diffcult
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C$(i), (ii)$
c 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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