NEC Quiz
Questions: 16 · 10 minutes
1. A circuit breaker trips again immediately after being reset. What is the most appropriate response?
Keep resetting it until the connected equipment starts normally
Replace it with a larger breaker of the same brand
Hold the breaker handle in the on position to identify the load
Leave it off and have the overload, short circuit, or ground fault investigated safely
2. What hazard is an arc-fault circuit interrupter primarily designed to address?
Arcing conditions with characteristics that can lead to electrical fires
Normal starting current from motors
Temporary loss of utility power
Reversed phase rotation in three-phase equipment
3. After opening a disconnect before electrical service work, which method best confirms that exposed parts are de-energized?
Check that connected lights are off and then begin work
Rely on the disconnect handle position and circuit directory
Use an appropriately rated tester, verify it on a known source before and after testing, and test the relevant conductors
Touch the conductor briefly with an insulated hand tool
4. In NEC terminology, what does it generally mean when equipment is “listed”?
The manufacturer has provided a written warranty for it
The equipment appears on the contractor's material schedule
An inspector has approved that individual unit at one job site
An acceptable product-evaluation organization has evaluated it and included it in a published list
5. What is the main role of the authority having jurisdiction, commonly called the AHJ?
Interpreting and enforcing the electrical requirements adopted in its jurisdiction
Manufacturing and listing all electrical products used locally
Writing installation instructions for electrical contractors
Guaranteeing that an installation will remain maintenance-free
6. What is the primary purpose of the National Electrical Code?
To serve as a complete design manual for efficient electrical systems
To provide practical safeguards for people and property from hazards arising from electricity use
To establish nationwide prices for electrical labor and materials
To replace all local inspection and permitting requirements
7. In a typical panel on the load side of the service disconnect, how should the grounded neutral and equipment grounding paths be handled?
Bond both to every metal raceway at each junction box
Remove the equipment grounding conductor because the neutral provides the return path
Connect neutral current to the enclosure to improve breaker performance
Keep the neutral isolated from the enclosure while bonding the enclosure to the equipment grounding path
8. What is the intended function of an equipment grounding conductor during a fault?
To carry the circuit's normal return current continuously
To provide an effective fault-current path that helps the protective device operate
To limit the normal operating voltage delivered to the load
To replace the grounded conductor whenever voltage drop is excessive
9. What is the principal reason electrical boxes have conductor fill limits?
To calculate voltage drop on long branch circuits
To establish the required working clearance in front of a panelboard
To prevent unsafe crowding and provide adequate space for conductors, splices, and devices
To determine the minimum size of a grounding electrode
10. How does a ground-fault circuit interrupter primarily detect a hazardous condition?
It compares current leaving and returning through the monitored conductors and responds to an imbalance
It measures supply voltage and opens whenever voltage rises slightly
It counts the number of appliances connected to the circuit
It monitors conductor temperature as its only operating method
11. An extension cord has been routed through a wall to supply a permanently installed appliance. What is the sound NEC-based response?
Leave it in place if the cord has three prongs
Protect the visible portion with tape and inspect it annually
Use a longer extension cord so its plug remains easy to reach
Replace the arrangement with an approved permanent wiring method and suitable connection point
12. Shelving and stored cartons block access to an electrical panel. What should be done?
Label the cartons so workers know a panel is behind them
Restore the required accessible working space and keep it clear of storage
Move only combustible items and keep noncombustible storage in place
Leave a narrow path that allows the panel door to open partway
13. Several current-carrying conductors share a raceway in a warm mechanical room. Which factors are especially relevant when determining allowable conductor ampacity?
Conductor color and the total raceway length only
Breaker brand, raceway color, and panel mounting height
Ambient temperature, number of current-carrying conductors, insulation rating, and applicable terminal limits
The utility meter rating alone
14. Which pairing matches the usual NEC identification of these conductors?
White or gray for equipment grounding; green for ungrounded conductors
Green for the grounded conductor; bare for ungrounded conductors
Green or bare for equipment grounding; white or gray for the grounded conductor
White for equipment grounding; gray for ungrounded conductors
15. Someone proposes installing a larger circuit breaker because the existing breaker trips when a load operates. Which principle should guide the response?
The cause should be determined, and the protective device must remain properly matched to conductor and equipment limitations
Breaker size can be increased if the load operates for less than three hours
A larger breaker is acceptable whenever it fits the panel
The breaker may be enlarged if the conductor insulation looks undamaged
16. Equipment marked only for dry locations is proposed under an outdoor roof where wind-driven rain can reach it. What is the appropriate decision?
Use the dry-location equipment because direct vertical rainfall is blocked
Use equipment or an enclosure identified for the actual damp or wet exposure
Install it if the circuit breaker has a higher interrupting rating
Wrap the equipment in a temporary plastic covering