Cathodic Protection Tester Practice Exam

Typical sources of stray currents include which of the following?

1. Cathodic protection systems

2. DC transit systems

3. Telluric currents

4. All of the above

The correct answer is: All of the above

Stray currents are unintended electrical currents that can flow through conductive materials and structures in the ground or other mediums, and they can lead to corrosion or other complications in engineering contexts. Cathodic protection systems can generate stray currents when they are improperly installed or when there is a failure in the system. These currents can seep into the soil around a structure and influence surrounding systems. DC transit systems, which use direct current for their operations, are another common source of stray currents. When these systems operate, they can induce currents in the surrounding earth and metal structures, particularly in urban areas where the infrastructure may be closely interconnected. Telluric currents are natural electrical currents that flow through the Earth and can also influence the electrical environment around buried structures. These currents can be generated by various natural phenomena, such as geomagnetic storms or variations in the Earth's magnetic field. Each of these sources can contribute to stray currents in different ways, highlighting the diverse origins of this phenomenon. Therefore, recognizing that all these options represent potential sources of stray currents makes the choice of "All of the above" the correct answer.