What does an ammeter connected in a circuit measure?

An ammeter is specifically designed to measure electric current flowing through a circuit. It operates based on the principle that the amount of charge (in coulombs) passing through the meter per second reflects the current in amperes. When connected in series within a circuit, the ammeter reads the total current, providing a direct measurement of this important parameter. Current is a fundamental concept in electrical circuits, influencing the functioning of various components.

Understanding that other devices are used for measuring different characteristics is important. For example, a voltmeter measures voltage and is connected in parallel, while an ohmmeter measures resistance, often when a circuit is de-energized. Similarly, power, which is the product of voltage and current, requires a different approach for accurate measurement. Thus, the key role of an ammeter in measuring current distinguishes it from these other functionalities.