City of Aurora – Electrical Contractor
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary purpose of the National Electrical Code
(NEC)?
A. To establish electrical utility rates
B. To provide standards for the safe installation of electrical systems
C. To regulate electrical equipment manufacturing costs
D. To determine electrician wages
Answer: B. To provide standards for the safe installation of electrical
systems
Rationale: The NEC establishes minimum safety requirements for
electrical installations. Its primary purpose is the practical safeguarding
of people and property from hazards arising from the use of electricity.
, 2. Which NEC article contains requirements for branch circuits?
A. Article 110
B. Article 210
C. Article 250
D. Article 300
Answer: B. Article 210
Rationale: NEC Article 210 covers branch circuits, including their
required ratings, conductor requirements, receptacle provisions, and
other installation rules.
3. Which conductor is generally identified by white or gray
insulation?
A. Ungrounded conductor
B. Equipment grounding conductor
C. Grounded conductor
D. Switch-leg conductor
Answer: C. Grounded conductor
Rationale: The grounded conductor, commonly called the neutral
conductor, is generally identified by a continuous white or gray finish or
by other permitted identification methods.
, 4. What is the maximum standard rating of an overcurrent
protective device permitted for a 12 AWG copper conductor
under typical conditions?
A. 15 amperes
B. 20 amperes
C. 25 amperes
D. 30 amperes
Answer: B. 20 amperes
Rationale: Under typical NEC conditions, 12 AWG copper conductors are
commonly protected at 20 amperes. Special applications can involve
additional requirements, so conductor ampacity and applicable
adjustment or correction factors must always be evaluated.
5. Which device is designed to interrupt a circuit when it detects a
difference between current flowing in ungrounded and grounded
conductors?
A. AFCI
B. GFCI
, C. Disconnect switch
D. Thermal overload
Answer: B. GFCI
Rationale: A ground-fault circuit interrupter monitors current balance
and trips when a ground-fault condition reaches its specified trip level.
GFCI protection is intended primarily to reduce the risk of electric shock.
6. What is the purpose of an equipment grounding conductor?
A. To carry normal load current
B. To increase circuit voltage
C. To provide a low-impedance path for fault current
D. To replace overcurrent protection
Answer: C. To provide a low-impedance path for fault current
Rationale: The equipment grounding conductor provides a conductive
path intended to facilitate operation of the overcurrent protective
device during a fault and help keep exposed metal parts at a safer
potential.
7. Which NEC article primarily addresses grounding and bonding?
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary purpose of the National Electrical Code
(NEC)?
A. To establish electrical utility rates
B. To provide standards for the safe installation of electrical systems
C. To regulate electrical equipment manufacturing costs
D. To determine electrician wages
Answer: B. To provide standards for the safe installation of electrical
systems
Rationale: The NEC establishes minimum safety requirements for
electrical installations. Its primary purpose is the practical safeguarding
of people and property from hazards arising from the use of electricity.
, 2. Which NEC article contains requirements for branch circuits?
A. Article 110
B. Article 210
C. Article 250
D. Article 300
Answer: B. Article 210
Rationale: NEC Article 210 covers branch circuits, including their
required ratings, conductor requirements, receptacle provisions, and
other installation rules.
3. Which conductor is generally identified by white or gray
insulation?
A. Ungrounded conductor
B. Equipment grounding conductor
C. Grounded conductor
D. Switch-leg conductor
Answer: C. Grounded conductor
Rationale: The grounded conductor, commonly called the neutral
conductor, is generally identified by a continuous white or gray finish or
by other permitted identification methods.
, 4. What is the maximum standard rating of an overcurrent
protective device permitted for a 12 AWG copper conductor
under typical conditions?
A. 15 amperes
B. 20 amperes
C. 25 amperes
D. 30 amperes
Answer: B. 20 amperes
Rationale: Under typical NEC conditions, 12 AWG copper conductors are
commonly protected at 20 amperes. Special applications can involve
additional requirements, so conductor ampacity and applicable
adjustment or correction factors must always be evaluated.
5. Which device is designed to interrupt a circuit when it detects a
difference between current flowing in ungrounded and grounded
conductors?
A. AFCI
B. GFCI
, C. Disconnect switch
D. Thermal overload
Answer: B. GFCI
Rationale: A ground-fault circuit interrupter monitors current balance
and trips when a ground-fault condition reaches its specified trip level.
GFCI protection is intended primarily to reduce the risk of electric shock.
6. What is the purpose of an equipment grounding conductor?
A. To carry normal load current
B. To increase circuit voltage
C. To provide a low-impedance path for fault current
D. To replace overcurrent protection
Answer: C. To provide a low-impedance path for fault current
Rationale: The equipment grounding conductor provides a conductive
path intended to facilitate operation of the overcurrent protective
device during a fault and help keep exposed metal parts at a safer
potential.
7. Which NEC article primarily addresses grounding and bonding?
