NCBEEC – Limited 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 the price of electrical materials
D. To establish contractor licensing fees
Answer: B. To provide standards for the safe installation of electrical
systems
Rationale: The NEC establishes minimum safety requirements for the
installation of electrical conductors, equipment, and systems. It is
intended primarily to safeguard people and property from hazards
associated with electricity.
, 2. Which NEC article contains the general 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
ratings, required outlets, overcurrent protection, and conductor
requirements. Understanding Article 210 is fundamental to residential
and limited electrical work.
3. What is the purpose of an overcurrent protective device such as a
circuit breaker?
A. To increase circuit voltage
B. To improve power factor
C. To protect conductors from excessive current
D. To provide additional electrical energy
Answer: C. To protect conductors from excessive current
,Rationale: Circuit breakers and fuses are designed to interrupt
excessive current before conductors become dangerously overheated.
Proper overcurrent protection helps prevent conductor damage and
electrical fires.
4. A circuit is supplied at 120 volts and has a resistance of 20 ohms.
Approximately how much current flows through the circuit?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Answer: C. 6 A
Rationale: Ohm's law states that I = E ÷ R. Therefore, 120 volts ÷ 20
ohms = 6 amperes.
5. What is the unit used to measure electrical resistance?
A. Volt
B. Ampere
C. Watt
D. Ohm
, Answer: D. Ohm
Rationale: Electrical resistance is measured in ohms (Ω). Voltage is
measured in volts, current in amperes, and power in watts.
6. What is the primary function of the grounding electrode system?
A. To increase circuit voltage
B. To provide a connection to earth for the electrical system
C. To eliminate the need for circuit breakers
D. To reduce conductor size
Answer: B. To provide a connection to earth for the electrical system
Rationale: The grounding electrode system connects the electrical
system to earth and helps stabilize system voltage with respect to
ground. It also provides a path for certain transient and fault
conditions.
7. Which conductor normally carries current back to the source in a
typical 120-volt branch circuit?
A. Equipment grounding conductor
B. Grounding electrode conductor
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 the price of electrical materials
D. To establish contractor licensing fees
Answer: B. To provide standards for the safe installation of electrical
systems
Rationale: The NEC establishes minimum safety requirements for the
installation of electrical conductors, equipment, and systems. It is
intended primarily to safeguard people and property from hazards
associated with electricity.
, 2. Which NEC article contains the general 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
ratings, required outlets, overcurrent protection, and conductor
requirements. Understanding Article 210 is fundamental to residential
and limited electrical work.
3. What is the purpose of an overcurrent protective device such as a
circuit breaker?
A. To increase circuit voltage
B. To improve power factor
C. To protect conductors from excessive current
D. To provide additional electrical energy
Answer: C. To protect conductors from excessive current
,Rationale: Circuit breakers and fuses are designed to interrupt
excessive current before conductors become dangerously overheated.
Proper overcurrent protection helps prevent conductor damage and
electrical fires.
4. A circuit is supplied at 120 volts and has a resistance of 20 ohms.
Approximately how much current flows through the circuit?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Answer: C. 6 A
Rationale: Ohm's law states that I = E ÷ R. Therefore, 120 volts ÷ 20
ohms = 6 amperes.
5. What is the unit used to measure electrical resistance?
A. Volt
B. Ampere
C. Watt
D. Ohm
, Answer: D. Ohm
Rationale: Electrical resistance is measured in ohms (Ω). Voltage is
measured in volts, current in amperes, and power in watts.
6. What is the primary function of the grounding electrode system?
A. To increase circuit voltage
B. To provide a connection to earth for the electrical system
C. To eliminate the need for circuit breakers
D. To reduce conductor size
Answer: B. To provide a connection to earth for the electrical system
Rationale: The grounding electrode system connects the electrical
system to earth and helps stabilize system voltage with respect to
ground. It also provides a path for certain transient and fault
conditions.
7. Which conductor normally carries current back to the source in a
typical 120-volt branch circuit?
A. Equipment grounding conductor
B. Grounding electrode conductor
