Cathodic Protection Tester Practice Exam

If the external circuit resistance of a constant voltage rectifier increases by two times, what will happen to the current?

1. The current will increase by two times

2. The current will remain the same

3. The current will be reduced by one-half

4. The current will double

The correct answer is: The current will be reduced by one-half

In a constant voltage rectifier, the relationship between voltage, current, and resistance can be understood through Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R). When the external circuit resistance increases by two times, the total effective resistance in the circuit increases. Since the voltage remains constant in a constant voltage system, according to Ohm's Law, this increased resistance leads to a decrease in current. Specifically, if resistance is doubled while maintaining the same voltage, the current will be halved. This inverse relationship demonstrates how increasing resistance affects current within the constraints of a fixed voltage source. Thus, when resistance doubles, the current does indeed reduce by one-half, making this the correct outcome in the scenario described.