MARYLAND MASTER ELECTRICIAN
EXAM PREP 2026: Practice Questions,
Verified Answers & Detailed
Rationales - Pass the NEC Exam with
Confidence
1. Which of the following 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
Answer: B. To provide a low-impedance fault current path
Rationale: Bonding ensures that conductive metal parts are electrically
connected together to create an effective ground-fault current path. This
allows overcurrent protective devices to operate quickly during a fault
condition, reducing 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 (exposed live parts
on one side, grounded parts on the other)?
, A. 2 feet
B. 2.5 feet
C. 3 feet
D. 4 feet
Answer: C. 3 feet
Rationale: NEC Table 110.26(A)(1) requires a minimum working clearance
of 3 feet for equipment operating at 151 to 600 volts to ground 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
Answer: C. 16 amperes
Rationale: Continuous loads are limited to 80% of the circuit rating unless
the overcurrent device and assembly are listed for 100% operation. 80% of
20 amperes equals 16 amperes .
4. Which NEC article primarily governs grounding and bonding
requirements?
A. Article 110
B. Article 210
C. Article 250
D. Article 300
Answer: C. Article 250
,Rationale: Article 250 contains the comprehensive requirements for
grounding and bonding of electrical systems, equipment, and enclosures .
5. What is the minimum burial depth for residential branch circuits
rated 120 volts or less with GFCI protection and maximum overcurrent
protection of 20 amperes using direct burial cable?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Answer: B. 12 inches
Rationale: NEC Table 300.5 permits residential branch circuits meeting
these conditions to be buried at a minimum depth of 12 inches when using
direct burial cable .
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
Answer: C. Phase voltage
Rationale: Phase voltage is measured between a phase conductor and the
neutral conductor in a wye-connected 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
Answer: C. To connect the grounded service conductor to the
grounding electrode system
Rationale: The grounding electrode conductor establishes the connection
between the electrical service and the grounding electrode system, helping
stabilize voltage to earth 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
Answer: B. Dry and damp locations
Rationale: THHN conductors are thermoplastic high-heat-resistant nylon-
coated conductors generally 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
Answer: C. Ground-fault circuit interrupter (GFCI)
EXAM PREP 2026: Practice Questions,
Verified Answers & Detailed
Rationales - Pass the NEC Exam with
Confidence
1. Which of the following 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
Answer: B. To provide a low-impedance fault current path
Rationale: Bonding ensures that conductive metal parts are electrically
connected together to create an effective ground-fault current path. This
allows overcurrent protective devices to operate quickly during a fault
condition, reducing 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 (exposed live parts
on one side, grounded parts on the other)?
, A. 2 feet
B. 2.5 feet
C. 3 feet
D. 4 feet
Answer: C. 3 feet
Rationale: NEC Table 110.26(A)(1) requires a minimum working clearance
of 3 feet for equipment operating at 151 to 600 volts to ground 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
Answer: C. 16 amperes
Rationale: Continuous loads are limited to 80% of the circuit rating unless
the overcurrent device and assembly are listed for 100% operation. 80% of
20 amperes equals 16 amperes .
4. Which NEC article primarily governs grounding and bonding
requirements?
A. Article 110
B. Article 210
C. Article 250
D. Article 300
Answer: C. Article 250
,Rationale: Article 250 contains the comprehensive requirements for
grounding and bonding of electrical systems, equipment, and enclosures .
5. What is the minimum burial depth for residential branch circuits
rated 120 volts or less with GFCI protection and maximum overcurrent
protection of 20 amperes using direct burial cable?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Answer: B. 12 inches
Rationale: NEC Table 300.5 permits residential branch circuits meeting
these conditions to be buried at a minimum depth of 12 inches when using
direct burial cable .
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
Answer: C. Phase voltage
Rationale: Phase voltage is measured between a phase conductor and the
neutral conductor in a wye-connected 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
Answer: C. To connect the grounded service conductor to the
grounding electrode system
Rationale: The grounding electrode conductor establishes the connection
between the electrical service and the grounding electrode system, helping
stabilize voltage to earth 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
Answer: B. Dry and damp locations
Rationale: THHN conductors are thermoplastic high-heat-resistant nylon-
coated conductors generally 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
Answer: C. Ground-fault circuit interrupter (GFCI)