Maryland Master Electrician Exam
Practice Questions and Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Guaranteed
Pass (GRADED A+)
1. What is the primary purpose of bonding metal raceways and
enclosures in an electrical system?
A. To increase conductor ampacity
B. To provide a low-impedance fault current path
C. To reduce voltage drop during normal operation
D. To improve power factor in branch circuits
Rationale: Bonding ensures a low-impedance path for fault current,
allowing overcurrent devices to operate quickly and reduce shock and fire
hazards .
2. According to the NEC, what is the minimum working clearance in
front of a 208-volt panelboard under Condition 2?
A. 2 feet
B. 2.5 feet
C. 3 feet
D. 4 feet
Rationale: NEC Table 110.26(A)(1) requires a minimum working clearance
of 3 feet for equipment rated 151 to 600 volts under Condition 2 .
, 3. What is the maximum continuous load permitted on a branch circuit
protected by a 20-amp overcurrent device?
A. 12 amperes
B. 15 amperes
C. 16 amperes
D. 20 amperes
Rationale: For continuous loads, the circuit is limited to 80% of its rating.
20 amps × 0.80 = 16 amperes .
4. Which NEC article primarily governs grounding and bonding
requirements?
A. Article 110
B. Article 250
C. Article 300
D. Article 430
Rationale: Article 250 contains the comprehensive requirements for
grounding and bonding .
5. What is the minimum burial depth for a residential branch circuit
rated 120 volts or less with GFCI protection, using direct burial cable?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Rationale: NEC Table 300.5 permits residential branch circuits meeting
these conditions to be buried at a minimum depth of 12 inches .
6. In a three-phase, four-wire wye system, the voltage measured from
any phase conductor to neutral is called:
A. Line voltage
, B. Induced voltage
C. Phase voltage
D. Potential difference factor
Rationale: Phase voltage is measured between a phase conductor and the
neutral in a wye system .
7. What is the purpose of a grounding electrode conductor?
A. To carry neutral current continuously
B. To connect equipment grounding conductors together
C. To connect the grounded service conductor to the grounding
electrode system
D. To increase transformer efficiency
Rationale: The grounding electrode conductor connects the service to the
grounding electrode system, stabilizing voltage during abnormal
conditions .
8. A conductor with insulation rated THHN is primarily suitable for:
A. Wet locations only
B. Dry and damp locations
C. Hazardous classified locations only
D. Underground direct burial only
Rationale: THHN conductors are suitable for dry and damp locations .
9. What device is intended to protect people against electric shock by
opening a circuit when a small imbalance in current occurs?
A. AFCI
B. Thermal overload relay
C. Ground-fault circuit interrupter (GFCI)
D. Surge protector
, Rationale: A GFCI detects current imbalances that indicate a ground fault
and rapidly opens the circuit to prevent shock .
10. Which of the following is the primary purpose of grounding an
electrical system?
A. Increase voltage
B. Reduce current flow
C. Provide a safe path for fault current
D. Improve lighting efficiency
Rationale: Grounding protects people and equipment by directing fault
current safely to earth .
11. Which NEC article covers grounding and bonding
requirements? (Repeats Question 4 for consistency with source material)
A. Article 110
B. Article 250
C. Article 300
D. Article 430
Rationale: NEC Article 250 establishes grounding and bonding rules .
12. What device protects against overloads in a circuit?
A. Fuse
B. Disconnect switch
C. Circuit breaker
D. Receptacle
Rationale: Circuit breakers are designed to automatically interrupt
excessive current flow caused by overloads or short circuits .
13. Which conductor is intentionally grounded in a single-phase
system?
Practice Questions and Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Guaranteed
Pass (GRADED A+)
1. What is the primary purpose of bonding metal raceways and
enclosures in an electrical system?
A. To increase conductor ampacity
B. To provide a low-impedance fault current path
C. To reduce voltage drop during normal operation
D. To improve power factor in branch circuits
Rationale: Bonding ensures a low-impedance path for fault current,
allowing overcurrent devices to operate quickly and reduce shock and fire
hazards .
2. According to the NEC, what is the minimum working clearance in
front of a 208-volt panelboard under Condition 2?
A. 2 feet
B. 2.5 feet
C. 3 feet
D. 4 feet
Rationale: NEC Table 110.26(A)(1) requires a minimum working clearance
of 3 feet for equipment rated 151 to 600 volts under Condition 2 .
, 3. What is the maximum continuous load permitted on a branch circuit
protected by a 20-amp overcurrent device?
A. 12 amperes
B. 15 amperes
C. 16 amperes
D. 20 amperes
Rationale: For continuous loads, the circuit is limited to 80% of its rating.
20 amps × 0.80 = 16 amperes .
4. Which NEC article primarily governs grounding and bonding
requirements?
A. Article 110
B. Article 250
C. Article 300
D. Article 430
Rationale: Article 250 contains the comprehensive requirements for
grounding and bonding .
5. What is the minimum burial depth for a residential branch circuit
rated 120 volts or less with GFCI protection, using direct burial cable?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Rationale: NEC Table 300.5 permits residential branch circuits meeting
these conditions to be buried at a minimum depth of 12 inches .
6. In a three-phase, four-wire wye system, the voltage measured from
any phase conductor to neutral is called:
A. Line voltage
, B. Induced voltage
C. Phase voltage
D. Potential difference factor
Rationale: Phase voltage is measured between a phase conductor and the
neutral in a wye system .
7. What is the purpose of a grounding electrode conductor?
A. To carry neutral current continuously
B. To connect equipment grounding conductors together
C. To connect the grounded service conductor to the grounding
electrode system
D. To increase transformer efficiency
Rationale: The grounding electrode conductor connects the service to the
grounding electrode system, stabilizing voltage during abnormal
conditions .
8. A conductor with insulation rated THHN is primarily suitable for:
A. Wet locations only
B. Dry and damp locations
C. Hazardous classified locations only
D. Underground direct burial only
Rationale: THHN conductors are suitable for dry and damp locations .
9. What device is intended to protect people against electric shock by
opening a circuit when a small imbalance in current occurs?
A. AFCI
B. Thermal overload relay
C. Ground-fault circuit interrupter (GFCI)
D. Surge protector
, Rationale: A GFCI detects current imbalances that indicate a ground fault
and rapidly opens the circuit to prevent shock .
10. Which of the following is the primary purpose of grounding an
electrical system?
A. Increase voltage
B. Reduce current flow
C. Provide a safe path for fault current
D. Improve lighting efficiency
Rationale: Grounding protects people and equipment by directing fault
current safely to earth .
11. Which NEC article covers grounding and bonding
requirements? (Repeats Question 4 for consistency with source material)
A. Article 110
B. Article 250
C. Article 300
D. Article 430
Rationale: NEC Article 250 establishes grounding and bonding rules .
12. What device protects against overloads in a circuit?
A. Fuse
B. Disconnect switch
C. Circuit breaker
D. Receptacle
Rationale: Circuit breakers are designed to automatically interrupt
excessive current flow caused by overloads or short circuits .
13. Which conductor is intentionally grounded in a single-phase
system?
