A. Voltage potential at the earth mat increases due to earthing
B. Voltage potential at the earth mat decreases due to earthing
C. Voltage potential at the earth mat remains zero irrespective of fault
D. None of the above
Answer: A. Voltage potential at the earth mat increases due to earthing
Explanation:
Increase in voltage potential at the earth mat caused by electrical faults that occur at electrical substations, power plants, or high voltage transmission lines.
When fault occurs, short circuit current flows through the equipment and into the grounding electrode.
The resistance of the Earth is non-zero, so current injected into the earth at the grounding electrode produces a potential rise with respect to a distant reference point.