OSHA Electrical Safety Quiz — 29 CFR 1926.400-449 Practice (Construction) — Page 3 of 4
Free OSHA 30-Hour Construction electrical safety practice test with 40 realistic scenarios. GFCI, AEGCP, temporary wiring, overhead line clearance, lockout/tagout, hazardous locations, and portable generator safety with 29 CFR 1926 Subpart K references. (Page 3 of 4)
0 / 10
Q21/ 40
A portable generator (5kW) is being used to power tools during the framing phase. The generator does NOT have GFCI outlets. Instead, the employer implements an Assured Equipment Grounding Conductor Program (AEGCP). What does the AEGCP require?
✅ Correct Answer: B
1926.404(b)(1)(iii)(B-F): the AEGCP must include: written description, competent person designation, daily visual inspection, and electrical testing for equipment grounding conductor continuity at intervals not exceeding 3 months (and before first use, after repair, after suspected damage). Tests must be recorded. The AEGCP is an alternative to GFCI protection — both achieve similar protection through different means.
Q22/ 40
A scissor lift is being repositioned inside a warehouse with exposed overhead bus bars at 480V, 20 feet above the floor. The lift's platform, when raised, reaches 19 feet. The operator raises the platform to adjust a light fixture 2 feet horizontally from the bus bars. What clearance is required?
✅ Correct Answer: B
1926.416(a)(1): no employee shall work in proximity to energized power circuits at a distance where accidental contact is possible. A scissor lift's metal platform at 19 feet, only 2 feet from 480V bus bars, is critically dangerous — platform sway, operator movement, or joystick error could bridge the gap. 480V arc flash can cause fatal burns. The bus bars should be de-energized and locked out before work within 10 feet, or barriers installed.
Q23/ 40
A worker using a portable circular saw notices the blade guard is sticking. The worker continues using the saw, holding the guard open manually when needed. Is this a violation?
✅ Correct Answer: B
1926.302(a)(1): electric power-operated tools shall be maintained in safe operating condition. 1926.302(a)(2): guards shall be in good working order and properly maintained. The blade guard is a required safety device. A guard that sticks open leaves the spinning blade exposed after the cut. Deliberately holding a guard open (defeating it) is a serious violation that can result in amputation.
Q24/ 40
A construction electrician is installing a temporary light string for job-site illumination. The string has 10 Edison-base sockets with bare bulbs, hung at 9 feet above the floor along a hallway where workers carry sheetrock. Is this compliant?
✅ Correct Answer: B
1926.405(a)(2)(ii)(E): temporary lights shall be equipped with guards to prevent accidental contact. 1926.405(a)(2)(ii)(C): temporary lighting strings shall not be supported by their conductors. Workers carrying 4×8 sheetrock at 9 feet height could easily strike a bare bulb, breaking it (flying glass, exposed energized filament).
Q25/ 40
A warehouse renovation requires cutting into an existing wall. The foreman tells a laborer to use a reciprocating saw to cut a 2×4-foot opening. The laborer does not know what is inside the wall. There is a live 120V circuit 6 inches behind the drywall. The saw blade contacts the cable, causing a short and flash. What should have been done?
✅ Correct Answer: B
1926.416(a)(1): no employee shall be permitted to work in proximity to electric power circuits unless protected. 1926.416(a)(2): where the exact location of energized circuits is unknown, employees shall be protected by insulating protective equipment or by the circuit being de-energized and grounded. The employer knew this was an existing building with live circuits. A circuit tracer or de-energizing the area before cutting are standard safe practices.
Advertisement
Google AdSense — Responsive In-Article Ad
Q26/ 40
Workers are using a 240V arc welder on a steel bridge project. The welder's metallic case has a 3-prong plug. During welding, a ground fault inside the welder energizes the case. A worker leaning against the bridge steel touches the welder case. What protection does the worker have?
✅ Correct Answer: B
1926.404(f)(3): the equipment grounding conductor shall provide a continuous, low-impedance path to ground for fault current. 1926.351(c)(3): welding machine frames shall be grounded. For a 240V fault to the case, the equipment ground provides a low-resistance path, allowing fault current (potentially hundreds of amps) to flow and trip the breaker via the magnetic trip mechanism in milliseconds. Without the equipment ground, the case stays energized at 240V.
Q27/ 40
A job-site temporary power pole has a 200A main breaker feeding multiple 20A receptacle circuits. One worker replaces a 20A breaker with a 30A breaker 'to stop the tripping.' The wiring is 12-gauge (rated for 20A). What is the hazard?
✅ Correct Answer: B
1926.405(a)(2)(ii)(A): all conductors shall be of sufficient size to carry the load. NEC Article 240.4(D): 12 AWG copper is limited to 20A overcurrent protection. Installing a 30A breaker on 20A-rated wiring means the wire can carry 30A before the breaker trips, potentially overheating to dangerous temperatures and causing insulation breakdown and fire.
Q28/ 40
An electrician is working on energized 277/480V bus bars with insulated tools, wearing no arc-flash PPE other than safety glasses. The electrician is a licensed journeyman. Is this compliant with OSHA?
✅ Correct Answer: B
1926.416(a)(1): employees must be protected against electric shock. NFPA 70E requires an Energized Electrical Work Permit for work within the limited approach boundary. 277/480V equipment has significant arc-flash hazard — an accidental short can produce an arc flash of 5+ cal/cm², causing second-degree burns. Safety glasses are inadequate for arc-flash protection. De-energizing and LOTO must be the first choice.
Q29/ 40
A construction worker is using a hammer drill outdoors on a bridge deck. The drill has a 3-prong plug and the worker is using a 50-foot, 14-gauge extension cord labeled for 'indoor use only.' It has recently rained. Is the extension cord acceptable?
✅ Correct Answer: B
1926.405(a)(2)(ii)(J): extension cords used on construction sites must be of the hard-service or junior hard-service type. Cords for indoor use only typically have lighter insulation not designed for moisture, abrasion, or UV exposure. Using an indoor cord in wet conditions can allow moisture to permeate the insulation, creating leakage current and shock hazard. The 'W' designation indicates moisture-resistant insulation.
Q30/ 40
On a multi-story construction project, temporary wiring for upper floors is run through a 12-inch × 12-inch floor opening. The cables contact the concrete edge. Workers step near this hole regularly. What protection is required?
✅ Correct Answer: B
1926.405(a)(2)(ii)(H): conductors passing through holes in floors or walls shall be protected from damage by enclosures, raceways, or other means. Concrete edges will eventually cut through cable insulation from vibration and movement. Additionally, the floor opening must be protected — 1926.501(b)(4) requires covers or guardrails.