Construction Coordinator Practice Exam

What can lead to false information during a resistive type of test?

1. Excessive signal strength

2. An impedance mismatch

3. Signal interference

4. Insufficient power supply

The correct answer is: An impedance mismatch

An impedance mismatch can indeed lead to false information during a resistive type of test. In electrical testing, the term impedance refers to the total opposition that a circuit presents to the passing of alternating current. When the impedance of the test device and the circuit being tested do not match, it can result in inaccurate measurements. This occurs because an impedance mismatch can cause reflections and losses in the signal, distorting the results you receive. Other factors, like excessive signal strength or insufficient power supply, may affect signal quality, but they do not inherently cause false reporting as directly as an impedance mismatch does. Signal interference can also contribute to noise in measurements, but the underlying reason for false information tied to resistive tests is primarily the relationship between impedances in the system. Thus, recognizing and managing impedance is crucial for obtaining accurate and reliable test results in electrical testing.