City of Springfield – Electrical Contractor
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale 2027 Q&A|
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1. What is the primary purpose of the National Electrical Code (NEC)?
A. To establish electrical utility rates
B. To provide minimum requirements for the safe installation of
electrical systems
C. To regulate the sale of electrical equipment
D. To establish labor union requirements
Answer: B. To provide minimum requirements for the safe installation
of electrical systems
Rationale: The NEC establishes minimum safety requirements for
electrical installations. Its primary objective is the practical
safeguarding of persons and property from hazards arising from the
,use of electricity. It is not intended to regulate utility rates, labor
organizations, or equipment sales.
2. Which article of the NEC contains the general requirements for
conductors for general wiring?
A. Article 250
B. Article 300
C. Article 310
D. Article 430
Answer: C. Article 310
Rationale: NEC Article 310 covers conductors for general wiring,
including conductor ampacity, insulation types, conductor sizes, and
related requirements. Article 250 primarily addresses grounding and
bonding, Article 300 covers wiring methods, and Article 430 addresses
motors and motor circuits.
3. What is the standard voltage between the ungrounded conductors
of a typical 120/240-volt single-phase residential service?
A. 120 volts
B. 208 volts
,C. 240 volts
D. 480 volts
Answer: C. 240 volts
Rationale: In a typical 120/240-volt single-phase system, each
ungrounded conductor is approximately 120 volts to the grounded
conductor. The voltage between the two ungrounded conductors is
240 volts.
4. Which conductor normally carries current under normal operating
conditions?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral or grounded conductor
D. Bonding jumper only
Answer: C. Neutral or grounded conductor
Rationale: The grounded conductor, commonly called the neutral, is
an intentionally grounded circuit conductor that normally carries
current in a typical multiwire or single-phase circuit. Equipment
grounding and bonding conductors generally do not carry normal load
current.
, 5. What is the minimum copper conductor size generally permitted for
a 20-ampere branch circuit under standard NEC conditions?
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 8 AWG
Answer: B. 12 AWG
Rationale: Under standard conditions, 12 AWG copper conductors are
commonly used for 20-ampere branch circuits. Fourteen AWG copper
is generally associated with 15-ampere circuits, while larger
conductors are used for higher ampacities or special applications.
6. What is the maximum standard overcurrent protection generally
permitted for a 14 AWG copper conductor?
A. 10 amperes
B. 15 amperes
C. 20 amperes
D. 30 amperes
Answer: B. 15 amperes
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 minimum requirements for the safe installation of
electrical systems
C. To regulate the sale of electrical equipment
D. To establish labor union requirements
Answer: B. To provide minimum requirements for the safe installation
of electrical systems
Rationale: The NEC establishes minimum safety requirements for
electrical installations. Its primary objective is the practical
safeguarding of persons and property from hazards arising from the
,use of electricity. It is not intended to regulate utility rates, labor
organizations, or equipment sales.
2. Which article of the NEC contains the general requirements for
conductors for general wiring?
A. Article 250
B. Article 300
C. Article 310
D. Article 430
Answer: C. Article 310
Rationale: NEC Article 310 covers conductors for general wiring,
including conductor ampacity, insulation types, conductor sizes, and
related requirements. Article 250 primarily addresses grounding and
bonding, Article 300 covers wiring methods, and Article 430 addresses
motors and motor circuits.
3. What is the standard voltage between the ungrounded conductors
of a typical 120/240-volt single-phase residential service?
A. 120 volts
B. 208 volts
,C. 240 volts
D. 480 volts
Answer: C. 240 volts
Rationale: In a typical 120/240-volt single-phase system, each
ungrounded conductor is approximately 120 volts to the grounded
conductor. The voltage between the two ungrounded conductors is
240 volts.
4. Which conductor normally carries current under normal operating
conditions?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral or grounded conductor
D. Bonding jumper only
Answer: C. Neutral or grounded conductor
Rationale: The grounded conductor, commonly called the neutral, is
an intentionally grounded circuit conductor that normally carries
current in a typical multiwire or single-phase circuit. Equipment
grounding and bonding conductors generally do not carry normal load
current.
, 5. What is the minimum copper conductor size generally permitted for
a 20-ampere branch circuit under standard NEC conditions?
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 8 AWG
Answer: B. 12 AWG
Rationale: Under standard conditions, 12 AWG copper conductors are
commonly used for 20-ampere branch circuits. Fourteen AWG copper
is generally associated with 15-ampere circuits, while larger
conductors are used for higher ampacities or special applications.
6. What is the maximum standard overcurrent protection generally
permitted for a 14 AWG copper conductor?
A. 10 amperes
B. 15 amperes
C. 20 amperes
D. 30 amperes
Answer: B. 15 amperes
