What does a voltmeter measure?

A voltmeter is specifically designed to measure the electrical potential difference between two points in a circuit, which is expressed in volts. This instrument is connected across the components or sections of the circuit where the voltage needs to be assessed. The primary function of the voltmeter is to determine how much potential energy is available to push electric charges through the circuit, often referred to as voltage.

Understanding the limitations and functionalities of a voltmeter is essential. For instance, it should be connected in parallel with the circuit component to ensure accurate readings, and it has a high internal resistance to minimize the current drawn from the circuit, preventing any significant impact on the circuit being tested. This makes it distinct from other measuring instruments, as it does not measure current, resistance, or power directly. Hence, the correct answer is that a voltmeter measures voltage.