Final answer:
Ground rods in engineering are typically 8 feet long, but depth and diameter guidelines can vary.
Step-by-step explanation:
In engineering, ground rods are used to establish an electrical connection with the earth. The minimum length allowed for driven ground rods under normal conditions is 8 feet. This ensures that the rod can effectively dissipate electrical charges into the ground.
To provide further context, the recommended depth and diameter of a ground rod can vary. An older guideline suggested 5 diameters in the side-to-side direction and 7-8 diameters in the depth direction. However, newer work suggests using as much as 8 diameters side-to-side and 15 diameters deep.
It is important to properly install ground rods to prevent electrical hazards and ensure safety in electrical systems.