Which device is used to measure voltage in an electrical circuit?

The device specifically designed to measure voltage in an electrical circuit is a voltmeter. A voltmeter is connected in parallel with the circuit component across which the voltage is to be measured. This configuration allows it to experience the same potential difference as the component, providing an accurate measurement of voltage.

While a galvanometer can indicate voltage indirectly by measuring small currents, it is not intended for direct voltage measurement. An ammeter, on the other hand, measures current and is connected in series with the circuit, which would not give an accurate voltage reading. A multimeter, while it can measure voltage, current, and resistance, is a versatile tool that combines functions of both a voltmeter and ammeter. However, the primary device established as a standard for directly measuring voltage is the voltmeter.