What is the common use of a voltmeter in electrical schematics?

A voltmeter is primarily used in electrical schematics to measure voltage, which is the electric potential difference between two points in a circuit. This tool is crucial for understanding how much electrical energy is available to drive current through circuit components. By measuring voltage, technicians and engineers can diagnose circuit functionality, verify that components are working as intended, and ensure that power is distributed correctly throughout the system.

Measuring current, resistance, or power is the function of other specialized instruments such as ammeters and ohmmeters. Power can be calculated using voltage and current measurements, but the voltmeter's dedicated role is specifically to quantify voltage levels in a circuit. This direct relationship with voltage measurement underscores the importance of the voltmeter in circuit analysis and design.