Which meter is used to measure voltage?

• A. Voltmeter
• B. Ammeter
• C. Ohmmeter
• D. Wattmeter

Answer: (A)

Voltage is the electric potential difference between two points, and the instrument designed to measure that quantity is the voltmeter. It is connected across the two points (in parallel with the element under test) so it can sense the potential difference without drawing significant current from the circuit. A voltmeter is built with high internal resistance to minimize loading the circuit. The reading is in volts.

An ammeter measures current and is placed in series to measure the flow of charge; an ohmmeter measures resistance by injecting a small current and observing the response; a wattmeter measures power, typically using both voltage and current. Therefore, the voltmeter is the best choice for measuring voltage.