Step potential is defined as the potential difference between which points?

• A. The voltage difference between two distant objects
• B. The potential difference between the feet of a person standing on the ground near an energized grounded object
• C. The voltage of the energized object
• D. The potential difference between the hands of a person standing on the ground near an energized grounded object

Answer: (C)

Step potential is the voltage difference between two points on the ground that are a step apart, such as the two feet of a person standing near an energized grounded object. When a fault raises the ground potential around the object, the surface of the earth near the fault becomes at a higher potential than further away. A person standing with two feet on different ground potentials can have current flow from one foot to the other through the legs, which is what creates the shock hazard. This concept focuses on the ground surface, not on the voltage of the energized object itself or on the potential difference between the hands. It’s the difference you’d measure between two points on the ground a short distance apart, typically where a person’s feet are placed.