California C-10 Electrical Contractor Practice Test

Answer choices

1. A. Leave the box recessed because a nonmetallic faceplate will cover the gap.
2. B. Fill the gap with ordinary caulk and install the device without changing the box position. This uses caulk to mask the setback but leaves the box edge recessed behind combustible material beyond the permitted condition.
3. C. Extend or reset the box so its front edge is flush with or projects from the combustible surface as required.
4. D. Install longer device screws so the receptacle can bridge the recessed box.

Wrong-answer review

• A. Leave the box recessed because a nonmetallic faceplate will cover the gap.: The assumption behind 'Leave the box recessed because a nonmetallic faceplate will cover the gap.' is not valid here: boxes in walls or ceilings of combustible material must be flush with or project from the finished surface. The stem instead requires the contractor to extend or reset the box so its front edge is flush with or projects from the combustible surface as required.
• B. Fill the gap with ordinary caulk and install the device without changing the box position. This uses caulk to mask the setback but leaves the box edge recessed behind combustible material beyond the permitted condition.: This option would use 'Fill the gap with ordinary caulk and install the device without changing the box position.', but boxes in walls or ceilings of combustible material must be flush with or project from the finished surface. The compliant course is to extend or reset the box so its front edge is flush with or projects from the combustible surface as required.
• D. Install longer device screws so the receptacle can bridge the recessed box.: 'Install longer device screws so the receptacle can bridge the recessed box.' is incorrect because boxes in walls or ceilings of combustible material must be flush with or project from the finished surface. In this scenario, that means the contractor must extend or reset the box so its front edge is flush with or projects from the combustible surface as required.

Answer choices

1. A. Use an indoor receptacle because the eave prevents direct rainfall.
2. B. Install a standard faceplate and apply silicone around its perimeter.
3. C. Verify the receptacle and cover are listed for the wet location, including the required weather-resistant and in-use protection where applicable.
4. D. Omit the cover if the branch circuit has GFCI protection.

Answer choices

1. A. Add the required coordination and commissioning activities to the project plan and labor estimate before committing to the shutdown.
2. B. Keep the estimate unchanged because coordination and testing are not part of an electrical contractor's project needs. This treats outage coordination, inspection, testing, and re-energization as owner activities even though they directly affect electrical labor and schedule.
3. C. Add only one hour of overtime and assume all agencies and the utility will be available on demand.
4. D. Exclude testing from the estimate and perform it only if the inspector requests it.

Answer choices

1. A. Use a phase-rotation meter because rain commonly changes phase sequence.
2. B. Use an infrared thermometer only, with the circuit de-energized and unloaded, while leaving the remaining design and protection requirements unchanged.
3. C. Use an insulation-resistance test to compare conductor-to-ground insulation condition and locate moisture-related leakage.
4. D. Use a receptacle polarity tester at the feeder disconnect.

Answer choices

1. A. Review the emergency-system separation requirements and route the emergency wiring as required rather than combining it with normal wiring by default.
2. B. Combine the circuits if all conductors have the same insulation voltage rating.
3. C. Combine the circuits whenever the raceway is metallic and bonded at both ends.
4. D. Use larger emergency conductors so sharing the raceway does not affect system reliability.

Answer choices

1. A. Select a wiring method and conductors permitted for the damp or wet conditions instead of NM-B.
2. B. Use the NM-B if the cable is sleeved in PVC for the exterior portion.
3. C. Coat the NM-B jacket with silicone before pulling it through the exterior raceway. This assumes a field-applied coating can convert a wiring method that is not permitted for the location into a wet-location cable.
4. D. Use NM-B only if the circuit is protected by a GFCI device.

Answer choices

1. A. Leave the box in place because lay-in ceilings make every above-ceiling box accessible by definition.
2. B. Relocate the pull box or duct so the box remains accessible after construction.
3. C. Seal the box cover permanently after inspection because no future access is required.
4. D. Install a larger box in the same blocked location to compensate for the reduced access.

Answer choices

1. A. Rigidly clamp the PVC at every foot so it cannot expand.
2. B. Provide expansion fittings or another approved means where thermal expansion and contraction are expected to cause movement.
3. C. Increase conductor slack only; conductor slack eliminates raceway thermal movement.
4. D. Use solvent cement at every support point to bond the PVC to the structure.

Answer choices

1. A. Use the plank if the crack is marked with paint so workers can avoid stepping on it. This leaves a visibly defective scaffold component in service; marking a crack does not restore the plank's required strength.
2. B. Remove the defective plank from service and replace it with suitable inspected planking before use.
3. C. Double the intended scaffold load rating to account for the weakened plank.
4. D. Place loose plywood over the crack and continue using the plank.

Answer choices

1. A. Treat the conductor as de-energized because a noncontact detector is definitive.
2. B. Use an appropriate contact-type test instrument and the required safe-work procedure to verify absence of voltage; do not rely on a noncontact detector alone.
3. C. Touch the conductor briefly with the back of the hand to confirm the detector reading. This uses the worker's body as a test method and does not satisfy safe verification of an electrically de-energized condition.
4. D. Ground the conductor with a screwdriver to prove it is de-energized.