Would you prefer a vlotmeter or a potentiomer to measure the emf of a battery?

Why do we prefer a potentiometer to measure emf of a cell rather than a voltmeter ?

The length of a wire of a potentiometer is 100 cm, and the emf of its stand and cell is E volt. It is employed to measure the emf of a battery whose internal resistance is 0.5Omega. If the balance point is obtained at l= 30 cm from the positive end, the emf of the battery is

Assertion A potentiometer is preferred over that of a voltmeter for measurement of emf of a cell Reason potentiometer does not draw any current from the cell.

Volymeter can not be used to measure emf to a cell potentiometer can be used to measure emf of a cell because

Why do you prefer the theatre than the cinema ?

State the uses of a potentiometer. Why is a potentiometer preferred over a voltmeter for measuring emf?