Practice Test GeeksNCCER (National Center for Construction Education & Research) Practice Test
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Electrical Flashcards

7 cards from real NCCER practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Electrical flashcards as text

  1. What is the minimum working clearance required in front of an electrical panel operating at 0–150 volts to ground, per NEC 110.26?

    Answer: 36 inches

    NEC 110.26 requires a minimum of 36 inches of clear working space in front of electrical equipment for voltages of 0–150V to ground.

  2. Which wire insulation designation is rated for use in both wet and dry locations?

    Answer: THWN

    THWN (Thermoplastic Heat-resistant Water-resistant Nylon-coated) insulation is approved for installation in both wet and dry locations.

  3. What is the correct sequence of steps for lockout/tagout (LOTO) before working on electrical equipment?

    Answer: De-energize, lock out the energy source, tag it, and verify zero energy state

    Proper LOTO requires de-energizing the equipment, applying a lockout device, attaching a warning tag, and verifying zero energy before work begins.

  4. What is the purpose of a bonding jumper in an electrical system?

    Answer: To ensure electrical continuity between metal parts for safe fault current flow

    A bonding jumper connects metal parts of an electrical system to ensure continuity and allow fault current to travel safely back to the source.

  5. What is the primary function of a transformer in an electrical distribution system?

    Answer: To change voltage levels using electromagnetic induction

    A transformer uses electromagnetic induction between primary and secondary windings to step voltage up or down as needed.

  6. What minimum safe distance must unqualified workers maintain from overhead power lines up to 50kV, per OSHA 1926.416?

    Answer: 10 feet

    OSHA 1926.416 requires unqualified workers to stay at least 10 feet away from overhead power lines energized up to 50kV.

  7. Which type of circuit breaker is specifically designed to detect and interrupt arc faults that could cause electrical fires?

    Answer: AFCI (Arc-Fault Circuit Interrupter) breaker

    An AFCI breaker detects the electrical signature of dangerous arc faults — a leading cause of electrical fires — and trips to interrupt the circuit.