What is the primary difference between a voltmeter and an ammeter?

The primary difference lies in the functions that these two instruments serve in an electrical circuit. A voltmeter is specifically designed to measure the electrical potential difference, or voltage, between two points in a circuit. This measurement indicates how much electrical force is available to drive current through a component. It is connected in parallel with the component whose voltage is being measured, allowing it to detect the voltage drop effectively.

On the other hand, an ammeter is used to measure the current (the flow of electric charge) flowing through a circuit. It is connected in series, which allows it to measure the amount of current passing through the circuit at any given moment.

This differentiation in function is crucial for properly diagnosing and understanding circuit behavior. For instance, knowing the voltage helps assess if components are operating within their specified parameters, while current measurement is essential for understanding how much power is consumed by the circuit.

Therefore, the choice that states a voltmeter measures voltage while an ammeter measures current accurately captures the fundamental role of each instrument in electrical measurements.