Cathodic Protection Tester Practice Exam

What challenge does voltage difference present in resistance testing?

1. It introduces thermal variations

2. It can mislead resistance calculations

3. It elevates the energy consumption

4. It causes physical circuit failures

The correct answer is: It can mislead resistance calculations

Voltage difference presents a significant challenge in resistance testing because it can mislead resistance calculations. During resistance testing, the measured resistance is influenced by the voltage applied to the circuit. If there is a considerable voltage difference across the connection points, it can lead to inaccurate readings due to the potential for voltage drop and incorrect current flow through the circuit elements. Thus, the calculated resistance may not accurately reflect the true resistance of the component being tested. In high-resistance measurements, small variations in voltage can disproportionately affect the current, leading to errors in resistance calculations. This highlights the importance of controlling the voltage applied during testing to ensure accurate results and reliable assessment of the component's integrity.