Compare a voltmeter and an ammeter.

Explanation

(i) Voltmeter is a high resistance device which is used to measure potential difference.
Ammeter is a low resistance device which is used to measure the current in electric circuit.
(ii) Voltmeter is obtained by using a high resistance of suitable value in series of the galvanometer.
Ammeter is obtained by using a low resistance shunt in parallel with a galvanometer.
(iii) Voltmeter is always connected in parallel to the conductor in circuit across which potential difference is to be determined.
Ammeter is always used in series of circuit to measure the current.
(iv) The range of voltmeter can be increased or decreased.
The range of ammeter, can be increased but cannot be decreased.
(v) Ideal voltmeter has infinite resistance.
Ideal ammeter has zero resistance.