It is preferable to measure the $e.m.f.$ of a cell by a potentiometer rather than by a voltmeter because of the following possible reasons.
$(i)$ In the case of a potentiometer,no current flows through the cell.
$(ii)$ The length of the potentiometer wire allows for 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
    $(i), (ii), (iii)$
  • C
    $(i), (ii)$
  • D
    $(i), (ii), (iii), (iv)$

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