Which of the following is typically used for grounding in electrical systems?

Grounding in electrical systems is essential for safety, as it provides a path for electric current to return to the ground in case of a fault, preventing electric shock or fire hazards. Metal pipes are a common choice for grounding because metals are excellent conductors of electricity. When a metal pipe is connected to ground, it can effectively carry fault current away from electrical equipment, ensuring that the system is safe and stable.

Wood, while widely used in construction, is an insulator and does not conduct electricity, making it unsuitable for grounding purposes. Plastic conduit also serves as a protective pathway for electrical wiring but lacks the conductive properties required for effective grounding. Flexible cable, while it may conduct electricity, is not typically used as a grounding method due to its lack of direct and stable contact with the earth, which is crucial for effective grounding.

In summary, metal pipes are favored in electrical systems for grounding due to their excellent conductive properties and their ability to safely redirect fault currents away from sensitive equipment and personnel.