The purpose of the grounding prong on a three-prong plug is to provide what?

• A. A safe path to earth
• B. To carry current to the load
• C. To reduce voltage
• D. To switch off the device

Answer: (A)

Grounding provides a safe path for fault current to earth, reducing the risk of electric shock. In a three-prong plug, the third prong connects to the equipment grounding conductor that ties the device’s metal parts (like the chassis) to the building’s grounding system. If insulation fails and a hot conductor contacts the metal case, the fault current travels through this grounding path to earth. Because this path is designed to be low resistance, the fault current is enough to trigger the circuit breaker or blow a fuse, disconnecting power quickly. The grounding path is not meant to carry normal operating current and does not set or reduce voltage; that’s the job of the hot and neutral conductors. The ground helps keep metal enclosures at earth potential, preventing shock if someone touches the device during a fault.