Final answer:
In electrical engineering, two grounding electrodes must be separated at least twice the maximum size of the largest electrode for effective grounding.
Step-by-step explanation:
In electrical engineering, when there is a requirement to add a second grounding electrode, the two electrodes must be separated at a distance equal to at least twice the maximum dimension of the largest electrode. This ensures that they are effectively independent and will provide adequate grounding.
For example, if one electrode has a length of 6 feet, the second electrode must be placed at least 12 feet away from it.
By following this separation requirement, the grounding electrodes will have a lower resistance to the earth, reducing the risk of electrical shock and providing safety in electrical systems.