Question

A ground ring encircling the building or building in direct contact with the earth at a depth below the earth's surface not below 2 1/2 ft and consisting of a minimum of 20 ft of bare copper sire will NOT be smaller than?

Answer 1

The question pertains to the minimum gauge of copper wire required for a grounding conductor in electrical grounding for a building. The NEC typically requires a grounding wire to be at least 4 AWG for safety and efficacy, though the exact requirement may vary with service size.

Step-by-step explanation:

The subject at hand is clearly related to Physics, specifically electrical grounding principles and requirements. According to National Electrical Code (NEC) regulations and common electrical practices, the specification for a grounding conductor surrounding a building involves using a copper wire. The characteristics of this wire must comply with certain minimum standards to ensure proper grounding and safety. The question seems to be inquiring about the minimum size (gauge) of copper wire that is acceptable for use as a grounding conductor. In general, when referring to grounding in electrical installations, the NEC specifies a minimum size based on the type of service and grounding needs. For a 20 ft (approximately 6.1 meters) length of copper wire, a common minimum is 4 AWG (American Wire Gauge) for copper, considering both the current-carrying capacity and corrosion resistance. Without additional context about the electrical service, for most residential services, 6 or 8 AWG is usually sufficient, but for larger services and for the sake of this question, not smaller than 4 AWG copper wire would be a conservative and safe choice.