Electrical Systems & Wiring Flashcards

When teaching students about branch circuit protection, which device is specifically designed to protect against both overloads AND arc faults?

Answer: AFCI breaker

Arc Fault Circuit Interrupters (AFCIs) detect dangerous arcing conditions that standard breakers miss, reducing fire risk from damaged wiring.

A student measures 120V between the hot and neutral terminals but 0V between the hot and ground. What does this indicate?

Answer: Open ground

An open ground means the ground wire is disconnected or missing, which is a shock hazard since the ground path is broken.

In a CTE electrical lab, the NEC requires GFCI protection for all 125V, 15A and 20A receptacles in which location?

Answer: All areas within 6 feet of a sink

NEC 210.8 requires GFCI protection for receptacles within 6 feet of a sink regardless of room type.

Which wiring method uses individual insulated conductors pulled through a metal or PVC conduit, offering the most protection and flexibility?

Answer: Conduit with THHN wire

THHN conductors in conduit allow individual wire replacement, offer mechanical protection, and can be rerouted by pulling new wires.

A student is sizing a conductor for a 240V, 30A clothes dryer circuit. What is the minimum wire gauge required by NEC?

Answer: 10 AWG

NEC requires 10 AWG copper conductors for 30A circuits, as 12 AWG is only rated for 20A.

When demonstrating conduit bending to students, what is the maximum number of degrees of bends allowed between pull points in a conduit run?

Answer: 360 degrees

NEC 358.26 limits conduit bends to 360 degrees total between pull boxes to prevent damage to conductors during wire pulling.

In teaching Ohm's Law applications, if a circuit has 120V source and a 24-ohm resistive load, what is the current?

Answer: 5A

Using I = V/R: 120V ÷ 24Ω = 5A.