What percentage of the resistance surrounding an electrode is found within a radius of 6 feet to 10 feet?

The correct percentage of the resistance surrounding an electrode that is found within a radius of 6 feet to 10 feet is indeed 90%. This concept relates to the principle of ground resistance and how electric fields disperse in soil around electrodes, such as grounding rods.

When an electrical charge is introduced into the ground through an electrode, the current spreads out from the electrode in a spherical manner. The majority of the current, and thus the ground resistance, is concentrated within a certain distance from the electrode, usually noted as 6 to 10 feet. It is observed that approximately 90% of the resistance encountered by the electrode occurs within this radius, indicating that the ground's resistive characteristics are concentrated close to the source of the electrical charge.

Understanding this helps in effectively designing grounding systems, ensuring safe electrical operations, and minimizing the potential for electric shock or equipment malfunction. Recognizing that most resistance is encountered near the electrode can guide linemen in selecting proper grounding strategies and measuring equipment to ensure the electrical safety of installations.