Which of the following instrument is used to measure amount of current in an electrical circuit?

Ammeter

The correct answer is Option 3: Ammeter

Electric current: If a net charge Q, flows across any cross-section of a conductor in time t, then the current I, through the cross-section is

I = \(\frac{Q}{t}\)

The electric current is expressed by a unit called ampere (A).

An instrument called ammeter measures electric current in a circuit. It is always connected in series in a circuit through which the current is to be measured.

Why not the others?

• Voltmeter: Measures voltage (potential difference), not current.

• Galvanometer: Detects small electric currents and shows their direction, but not suitable for measuring larger currents accurately.

• Potentiometer: Measures voltage precisely and can compare e.m.f., but does not directly measure current.