Which device is used to measure voltage values?

A voltmeter is the device specifically designed to measure voltage values in an electrical circuit. It functions by connecting in parallel with the circuit component across which the voltage is to be measured. The voltmeter displays the potential difference between the two points, allowing users to assess the voltage in various applications, such as checking battery voltage or troubleshooting electrical systems.

In contrast, an ammeter measures current, which is the flow of electric charge through a circuit, and it is typically connected in series. An ohmmeter measures resistance, providing information about the opposition to current flow in a circuit, and is used to test the integrity of components. A transformer, on the other hand, is utilized to change the voltage levels within an electric power system but does not measure voltage itself. Each of these devices has a distinct purpose in electrical measurements, making the voltmeter the correct choice for measuring voltage values.