Which device is used to measure voltage?

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

Answer: (A)

Measuring voltage means sensing the electrical potential difference between two points in a circuit. The device used for this purpose is a voltmeter. It’s designed to be connected across the points where you want to know the voltage, effectively in parallel, and it has a high internal resistance so it doesn’t draw significant current from the circuit or alter the voltage being measured. The meter displays the value in volts, whether in analog or digital form.

In contrast, an ammeter measures current and is placed in series to read the flow of charge, an ohmmeter measures resistance and is used with the circuit powered off to determine how much resistance a component has, and a wattmeter measures electrical power, which depends on both voltage and current.