Delaware Master Electrician Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. Which of the following is the primary purpose of the National
Electrical Code (NEC)?
A. To reduce electricity bills
B. To standardize electrical product manufacturing
C. To ensure electrical safety
D. To regulate utility companies
Rationale: The NEC provides guidelines and standards to ensure the
safe installation of electrical wiring and equipment.
2. What is the minimum size copper grounding electrode conductor for a
100-amp service?
A. 6 AWG
B. 8 AWG
C. 4 AWG
D. 2 AWG
Rationale: According to NEC Table 250.66, a 4 AWG copper
conductor is the minimum size for grounding a 100-amp service.
3. Which type of conduit is typically used in wet locations?
A. EMT
B. PVC
C. RMC
D. All of the above
Rationale: EMT, PVC, and RMC are all suitable for wet locations if
properly installed.
4. What is the maximum overcurrent protection for a 14 AWG copper
conductor in a residential circuit?
A. 10 amps
, B. 15 amps
C. 20 amps
D. 25 amps
Rationale: NEC Table 310.16 specifies that a 14 AWG copper
conductor is rated for 15 amps in typical residential applications.
5. In a 120/240V single-phase system, what is the voltage between the
two hot legs?
A. 120V
B. 208V
C. 240V
D. 480V
Rationale: In a 120/240V system, the voltage between the two hot
conductors is 240 volts.
6. Which of the following devices provides overcurrent protection?
A. Switch
B. Circuit breaker
C. Conduit
D. Receptacle
Rationale: Circuit breakers protect conductors and equipment by
interrupting current in the event of an overcurrent condition.
7. What is the minimum working space required in front of an electrical
panel rated 200A?
A. 24 inches
B. 28 inches
C. 36 inches
D. 48 inches
Rationale: NEC 110.26 requires a minimum of 36 inches of clear
working space in front of electrical equipment.
8. Which type of wire is commonly used in residential branch circuits?
A. XHHW
B. SE cable
C. NM (Non-metallic sheathed) cable
D. USE cable
Rationale: NM cable, such as Romex, is commonly used in
residential branch circuits.
9. What is the primary function of a GFCI outlet?
A. Increase voltage
, B. Reduce current
C. Protect people from electrical shock
D. Protect appliances
Rationale: GFCI outlets detect ground faults and interrupt the circuit
to protect people from electrical shock.
10. When installing a three-way switch circuit, how many travelers
are required?
A. 1
B. 2
C. 3
D. 4
Rationale: Three-way switches require two traveler wires to allow
switching from two locations.
11. What is the NEC minimum burial depth for a 120V NM cable in
residential applications?
A. 12 inches
B. 24 inches
C. 18 inches
D. 30 inches
Rationale: NEC 300.5 specifies a minimum burial depth of 24 inches
for NM cable under residential conditions.
12. Which of the following is an acceptable method for supporting
electrical raceways?
A. Tape
B. Wire
C. Hangers or straps
D. Adhesive
Rationale: NEC requires raceways to be securely supported using
hangers or straps at prescribed intervals.
13. What is the color code for a grounded conductor in a residential
120/240V system?
A. Black
B. Red
C. Blue
D. White
Rationale: NEC 200.6 requires grounded (neutral) conductors to be
white or gray.
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. Which of the following is the primary purpose of the National
Electrical Code (NEC)?
A. To reduce electricity bills
B. To standardize electrical product manufacturing
C. To ensure electrical safety
D. To regulate utility companies
Rationale: The NEC provides guidelines and standards to ensure the
safe installation of electrical wiring and equipment.
2. What is the minimum size copper grounding electrode conductor for a
100-amp service?
A. 6 AWG
B. 8 AWG
C. 4 AWG
D. 2 AWG
Rationale: According to NEC Table 250.66, a 4 AWG copper
conductor is the minimum size for grounding a 100-amp service.
3. Which type of conduit is typically used in wet locations?
A. EMT
B. PVC
C. RMC
D. All of the above
Rationale: EMT, PVC, and RMC are all suitable for wet locations if
properly installed.
4. What is the maximum overcurrent protection for a 14 AWG copper
conductor in a residential circuit?
A. 10 amps
, B. 15 amps
C. 20 amps
D. 25 amps
Rationale: NEC Table 310.16 specifies that a 14 AWG copper
conductor is rated for 15 amps in typical residential applications.
5. In a 120/240V single-phase system, what is the voltage between the
two hot legs?
A. 120V
B. 208V
C. 240V
D. 480V
Rationale: In a 120/240V system, the voltage between the two hot
conductors is 240 volts.
6. Which of the following devices provides overcurrent protection?
A. Switch
B. Circuit breaker
C. Conduit
D. Receptacle
Rationale: Circuit breakers protect conductors and equipment by
interrupting current in the event of an overcurrent condition.
7. What is the minimum working space required in front of an electrical
panel rated 200A?
A. 24 inches
B. 28 inches
C. 36 inches
D. 48 inches
Rationale: NEC 110.26 requires a minimum of 36 inches of clear
working space in front of electrical equipment.
8. Which type of wire is commonly used in residential branch circuits?
A. XHHW
B. SE cable
C. NM (Non-metallic sheathed) cable
D. USE cable
Rationale: NM cable, such as Romex, is commonly used in
residential branch circuits.
9. What is the primary function of a GFCI outlet?
A. Increase voltage
, B. Reduce current
C. Protect people from electrical shock
D. Protect appliances
Rationale: GFCI outlets detect ground faults and interrupt the circuit
to protect people from electrical shock.
10. When installing a three-way switch circuit, how many travelers
are required?
A. 1
B. 2
C. 3
D. 4
Rationale: Three-way switches require two traveler wires to allow
switching from two locations.
11. What is the NEC minimum burial depth for a 120V NM cable in
residential applications?
A. 12 inches
B. 24 inches
C. 18 inches
D. 30 inches
Rationale: NEC 300.5 specifies a minimum burial depth of 24 inches
for NM cable under residential conditions.
12. Which of the following is an acceptable method for supporting
electrical raceways?
A. Tape
B. Wire
C. Hangers or straps
D. Adhesive
Rationale: NEC requires raceways to be securely supported using
hangers or straps at prescribed intervals.
13. What is the color code for a grounded conductor in a residential
120/240V system?
A. Black
B. Red
C. Blue
D. White
Rationale: NEC 200.6 requires grounded (neutral) conductors to be
white or gray.
