What is the typical distance associated with measuring step voltage?

Measuring step voltage typically involves evaluating the potential difference that occurs across a person's body when they are in contact with the ground under short-circuit conditions, such as during an electrical fault. The distance of 3 feet is commonly used in calculations and guidelines regarding step voltage because it represents an average stride length for an adult. This distance is significant because when an individual stands with their feet apart, the voltage can vary across their body due to the ground potential gradient created by fault conditions.

Utilizing 3 feet as a standard measurement allows for a practical assessment of the risk involved in an electrical fault scenario, providing insights into safe distances and potential hazards. This specific distance helps ensure that safety protocols are based on a realistic range of human interaction with electrical systems. Other distances provided in the choices may not align with standard guidelines or could represent either too short or too long a distance to accurately assess the risks associated with step voltage.