Deep Dive: G0B05
The correct answer is B: Current flowing from one or more of the hot wires directly to ground. The condition that will cause a ground fault circuit interrupter (GFCI) to disconnect AC power is current flowing from one or more of the hot wires directly to ground. GFCIs detect current imbalance (current going to ground instead of returning through neutral) and trip. For amateur radio operators, this is critical electrical safety. Understanding this helps ensure safe electrical operation.
Why Other Answers Are Wrong
Option A: Incorrect. Current flowing from hot to neutral is normal operation - GFCI doesn't trip on normal current flow. Hot to neutral is normal. Option C: Incorrect. Overvoltage on hot wires doesn't cause GFCI to trip - GFCIs detect current imbalance, not overvoltage. Overvoltage isn't detected. Option D: Incorrect. Since A and C are not correct, 'all of the above' cannot be correct. Only current to ground causes GFCI to trip.
Exam Tip
GFCI trips = current flowing from hot wires directly to ground. Think 'G'FCI = 'G'round 'F'ault 'C'urrent 'I'mbalance. GFCIs detect current imbalance (current going to ground instead of returning through neutral) and trip. Not hot to neutral (normal), not overvoltage - just current to ground.
Memory Aid
GFCI trips = current flowing from hot wires directly to ground. Think 'G'FCI = 'G'round 'F'ault. GFCIs detect current imbalance (current going to ground instead of returning through neutral) and trip. Critical electrical safety protection.
Real-World Example
A GFCI: It monitors current flow. If current flows from a hot wire directly to ground (instead of returning through neutral), the GFCI detects the imbalance and trips, disconnecting AC power. This protects against electric shock - if you touch a hot wire, current flows through you to ground, and the GFCI trips. Current to ground causes GFCI to trip.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G0B
Reference: National Electrical Code
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G0B topic.