Practice Test Newest (2026 Update) Actual
Practice Questions – Set 100 Most Common
Exam Questions And Answers In Details 100%
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1. A contractor installs a 200-amp residential service. What is the minimum
size copper grounding electrode conductor required for a rod electrode?
A. 8 AWG
B. 6 AWG
C. 4 AWG
D. 2 AWG
✔ Correct Answer: B (6 AWG)
Explanation: NEC 250.66(A) specifies that for rod, pipe, or plate electrodes,
the grounding electrode conductor is not required to be larger than 6 AWG
copper.
2. Which NEC article covers grounding and bonding requirements?
A. Article 210
B. Article 250
C. Article 300
D. Article 430
✔ Correct Answer: B (Article 250)
Explanation: NEC Article 250 specifically addresses grounding and bonding
requirements for electrical systems.
3. What is the maximum voltage allowed for general lighting circuits in
dwelling units?
A. 120 volts
, B. 240 volts
C. 277 volts
D. 480 volts
✔ Correct Answer: A (120 volts)
Explanation: Standard general lighting circuits in residential dwellings are
limited to 120 volts.
4. A 20-amp branch circuit uses 12 AWG copper conductors. What is the
allowable ampacity?
A. 15 amps
B. 20 amps
C. 25 amps
D. 30 amps
✔ Correct Answer: B (20 amps)
Explanation: NEC Table 310.16 assigns 20 amps as the allowable ampacity
for 12 AWG copper conductors under typical conditions.
5. What type of circuit breaker trips instantly under short-circuit conditions?
A. Thermal
B. Magnetic
C. Dual-element
D. Time-delay
✔ Correct Answer: B (Magnetic)
Explanation: Magnetic breakers respond instantly to high fault currents such
as short circuits.
6. In a bathroom, receptacles must be GFCI protected and installed on at least
what size circuit?
A. 15 amp
B. 20 amp
C. 25 amp
D. 30 amp
✔ Correct Answer: B (20 amp)
, Explanation: NEC 210.11(C)(3) requires at least one 20-amp circuit for
bathroom receptacles.
7. What is the minimum burial depth for rigid metal conduit under residential
driveways?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
✔ Correct Answer: B (12 inches)
Explanation: NEC Table 300.5 specifies 12 inches minimum burial depth for
RMC under driveways.
8. Which device protects against overloads and short circuits?
A. Disconnect switch
B. Circuit breaker
C. Transformer
D. Contactor
✔ Correct Answer: B (Circuit breaker)
Explanation: Circuit breakers provide both overload and short-circuit
protection.
9. A conductor is considered continuous load if it operates for how long?
A. 1 hour
B. 2 hours
C. 3 hours
D. 4 hours
✔ Correct Answer: C (3 hours)
Explanation: NEC defines continuous load as a load expected to run for 3
hours or more.
10.What is the required rating for overcurrent protection for continuous loads?
A. 100% of load
B. 110% of load