Maryland Master Electrician Examination
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A| Instant
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1. Which organization publishes the National Electrical Code (NEC),
which forms the technical basis for many electrical installation
requirements in Maryland?
A. OSHA
B. ANSI
C. NFPA
D. NEMA
Answer: C. NFPA
Rationale: The National Fire Protection Association (NFPA) publishes
NFPA 70, the National Electrical Code. The NEC establishes widely
adopted requirements for electrical installations, although Maryland
,jurisdictions may adopt and amend editions through their applicable
laws and regulations.
2. What is the primary purpose of a circuit breaker in an electrical
distribution system?
A. Increase circuit voltage
B. Provide overcurrent protection
C. Improve power factor
D. Reduce conductor resistance
Answer: B. Provide overcurrent protection
Rationale: A circuit breaker is designed to open a circuit when current
exceeds its permitted level. This protects conductors and equipment
from damage caused by overloads and short circuits.
3. In a 120/240-volt single-phase, three-wire system, what voltage
normally exists between the two ungrounded conductors?
A. 120 volts
B. 180 volts
C. 208 volts
D. 240 volts
Answer: D. 240 volts
,Rationale: In a typical 120/240-volt single-phase system, each
ungrounded conductor is approximately 120 volts to the grounded
conductor. The two ungrounded conductors are opposite in phase,
producing approximately 240 volts between them.
4. What is the main function of the grounded conductor in a typical
120/240-volt residential system?
A. Carry normal unbalanced current
B. Serve as the grounding electrode
C. Protect against mechanical damage
D. Increase available fault current
Answer: A. Carry normal unbalanced current
Rationale: The grounded conductor, commonly called the neutral,
carries the unbalanced current from the 120-volt loads back toward
the source in a multiwire system. It is not interchangeable with the
equipment grounding conductor.
5. Which conductor is intended to provide a low-impedance path for
fault current back to the source?
A. Grounded conductor only
B. Equipment grounding conductor
, C. Ungrounded conductor
D. Service-entrance conductor
Answer: B. Equipment grounding conductor
Rationale: The equipment grounding conductor connects normally
non-current-carrying metal parts to the grounding system. During a
fault, it provides a low-impedance path that helps operate the
overcurrent protective device.
6. What is the purpose of bonding electrically conductive metal
parts together?
A. To increase circuit voltage
B. To eliminate all current flow
C. To establish electrical continuity and facilitate fault-current clearing
D. To reduce conductor ampacity
Answer: C. To establish electrical continuity and facilitate fault-
current clearing
Rationale: Bonding creates an electrically continuous conductive path
between applicable metal parts. This helps ensure that a fault to
metal equipment produces sufficient fault current to operate the
protective device.
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A| Instant
Download Pdf
1. Which organization publishes the National Electrical Code (NEC),
which forms the technical basis for many electrical installation
requirements in Maryland?
A. OSHA
B. ANSI
C. NFPA
D. NEMA
Answer: C. NFPA
Rationale: The National Fire Protection Association (NFPA) publishes
NFPA 70, the National Electrical Code. The NEC establishes widely
adopted requirements for electrical installations, although Maryland
,jurisdictions may adopt and amend editions through their applicable
laws and regulations.
2. What is the primary purpose of a circuit breaker in an electrical
distribution system?
A. Increase circuit voltage
B. Provide overcurrent protection
C. Improve power factor
D. Reduce conductor resistance
Answer: B. Provide overcurrent protection
Rationale: A circuit breaker is designed to open a circuit when current
exceeds its permitted level. This protects conductors and equipment
from damage caused by overloads and short circuits.
3. In a 120/240-volt single-phase, three-wire system, what voltage
normally exists between the two ungrounded conductors?
A. 120 volts
B. 180 volts
C. 208 volts
D. 240 volts
Answer: D. 240 volts
,Rationale: In a typical 120/240-volt single-phase system, each
ungrounded conductor is approximately 120 volts to the grounded
conductor. The two ungrounded conductors are opposite in phase,
producing approximately 240 volts between them.
4. What is the main function of the grounded conductor in a typical
120/240-volt residential system?
A. Carry normal unbalanced current
B. Serve as the grounding electrode
C. Protect against mechanical damage
D. Increase available fault current
Answer: A. Carry normal unbalanced current
Rationale: The grounded conductor, commonly called the neutral,
carries the unbalanced current from the 120-volt loads back toward
the source in a multiwire system. It is not interchangeable with the
equipment grounding conductor.
5. Which conductor is intended to provide a low-impedance path for
fault current back to the source?
A. Grounded conductor only
B. Equipment grounding conductor
, C. Ungrounded conductor
D. Service-entrance conductor
Answer: B. Equipment grounding conductor
Rationale: The equipment grounding conductor connects normally
non-current-carrying metal parts to the grounding system. During a
fault, it provides a low-impedance path that helps operate the
overcurrent protective device.
6. What is the purpose of bonding electrically conductive metal
parts together?
A. To increase circuit voltage
B. To eliminate all current flow
C. To establish electrical continuity and facilitate fault-current clearing
D. To reduce conductor ampacity
Answer: C. To establish electrical continuity and facilitate fault-
current clearing
Rationale: Bonding creates an electrically continuous conductive path
between applicable metal parts. This helps ensure that a fault to
metal equipment produces sufficient fault current to operate the
protective device.
