Cathodic Protection Tester Practice Exam

What does an ammeter measure, and in which units?

1. Voltage in Volts

2. Resistance in Ohms

3. Current in Amperes

4. Power in Watts

The correct answer is: Current in Amperes

An ammeter is a specialized instrument designed to measure the flow of electric current in a circuit. It quantifies the current in terms of amperes, which is the basic unit of electric current in the International System of Units (SI). The ammeter is connected in series with the circuit to ensure that all the current flowing through the circuit also passes through the ammeter, allowing for an accurate measurement. The choice of amperes as the unit is significant because it directly reflects the movement of electric charge. A higher number of amperes indicates a stronger flow of electric current, making it an essential tool for evaluating electrical systems, including those used in cathodic protection. The other choices pertain to different electrical measurements: voltage is measured in volts, resistance in ohms, and power in watts. Each of these measurements serves unique purposes and requires different instruments for accurate evaluation, thus highlighting the specific functionality of an ammeter in measuring current accurately in amperes.