Which of the following instrument is used to measure amount of current in an electrical circuit?
Answer & explanation
Correct answer: option 3
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?
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Voltmeter: Measures voltage (potential difference), not current.
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Galvanometer: Detects small electric currents and shows their direction, but not suitable for measuring larger currents accurately.
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Potentiometer: Measures voltage precisely and can compare e.m.f., but does not directly measure current.