What does a voltmeter measure in an electrical circuit?

A voltmeter measures voltage in an electrical circuit. Voltage, often referred to as electric potential difference, is the measure of the energy per unit charge available to move electric charge between two points in the circuit. Essentially, it tells us how much energy is provided to charge carriers (like electrons) as they move around the circuit.

When you connect a voltmeter across two points in a circuit, it provides a reading that reflects this potential difference, showcasing how much energy is available to push the charges through resistors and other components. Understanding voltage is crucial for analyzing how an electrical circuit operates, as it helps determine how much current will flow given the resistance in the circuit.

Other options relate to aspects of electrical circuits but do not pertain to what a voltmeter measures. Thus, the relevance of voltage in this context is paramount for anyone studying electrical concepts.