Cathodic Protection Tester Practice Exam

How is an ammeter connected to take a reading?

1. In free air

2. In series with the circuit

3. In parallel with the circuit

4. Across the load

The correct answer is: In series with the circuit

To accurately take a reading with an ammeter, it must be connected in series with the circuit. This method allows the ammeter to measure the current flowing through the circuit because it becomes part of the path that the current travels. As a result, the ammeter senses the entire amount of current that is passing through the circuit at that point. Connecting an ammeter in series ensures that all of the current flowing through the circuit also flows through the ammeter, providing an accurate measurement of the current. If it were connected in parallel, which is often the case with voltmeters, the ammeter would create a short circuit, potentially damaging the meter and providing meaningless readings since it would not measure the current in the desired circuit. This design principle is crucial for electrical safety and measurement accuracy in any circuit analysis.