Which of the following must have at least 2 square feet of surface area exposed to the surrounding earth?

• A. Grounding electrode conductor
• B. Plate electrode
• C. Ground rod
• D. Bonding jumper

Answer: (B)

The correct answer is the plate electrode because it is specifically designed to be in contact with the earth in a way that allows for efficient grounding. A plate electrode needs to have a minimum surface area of 2 square feet exposed to the surrounding earth to effectively dissipate electrical energy into the ground. This exposure is critical for reducing electrical resistance and achieving proper grounding, which helps protect people and equipment from electrical faults or surges.

In contrast, grounding electrode conductors, ground rods, and bonding jumpers have different requirements and functions in grounding systems. Grounding electrode conductors are the wires that connect grounding electrodes to the grounding system but do not need to have a specific surface area exposed. Ground rods also serve as grounding electrodes but do not have a surface area requirement as large as that of plate electrodes; they are driven into the ground and rely on length rather than surface area for grounding effectiveness. Bonding jumpers are used to connect different parts of a grounding system and do not have a surface area requirement either. Thus, the plate electrode is the only option that specifically mandates having at least 2 square feet exposed to the earth.