Pressure : Barometer :: Current : _______?_______
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Ammeter
A barometer is the instrument that measures pressure (of the atmosphere). In the same way, the instrument that measures electric current is the ammeter.
Why the other options are incorrect
Option (1) Thermometer — Incorrect. It measures temperature.
Option (2) Voltmeter — Incorrect. It measures the potential difference (voltage) between two points.
Option (3) Galvanometer — Incorrect. It detects the presence and direction of a small current; an ammeter is a galvanometer adapted to read amperes.