NEW MEXICO ER-1 RESIDENTIAL ELECTRICAL CONTRACTOR
EXAM COMPLETE EXAM QUESTIONS AND VERIFIED
ANSWERS | 2026–2027 LATEST UPDATE | GUARANTEED
PASS | DETAILED RATIONALES | FULL STUDY GUIDE | EXAM
PREP | PRACTICE TEST | CERTIFICATION PREPARATION
1. According to the New Mexico Administrative Code (NMAC 14.10.4), which of the following best
describes the scope of work permitted under an ER-1 Residential Electrical Wiring license?
A) Any residential and commercial electrical work, including hotels and motels.
B) One- and two-family dwellings only, with multi-family units limited to ground-floor units with no
occupancies above or below.
C) All multi-family dwellings without restriction, regardless of the number of floors.
D) Only new construction of single-family homes and duplexes.
Correct Answer: B) One- and two-family dwellings only, with multi-family units limited to ground-
floor units with no occupancies above or below.
Rationale: The NMAC explicitly restricts the ER-1 license to one- and two-family dwelling units and
multi-family dwellings where all units are on the ground floor with no occupancies above or below. It
prohibits commercial work such as motels and hotels. This defines the legal scope for a residential
electrical contractor in New Mexico .
2. What is the minimum work experience required for an individual to qualify as the qualifying party
for an ER-1 Residential Electrical Wiring license in New Mexico?
A) 1 year (2,000 hours)
B) 2 years (4,000 hours)
C) 3 years (6,000 hours)
D) 4 years (8,000 hours)
Correct Answer: B) 2 years (4,000 hours)
Rationale: The New Mexico Construction Industries Division (CID) requires the qualifying party for an
ER-1 license to provide proof of at least two years, or 4,000 hours, of verifiable experience in
residential electrical wiring. This is a key eligibility requirement .
3. What is the maximum number of dwelling units an ER-1 contractor may contract for in a single
building or structure?
A) 2
B) 3
C) 4
D) 6
Correct Answer: C) 4
Rationale: The regulations governing the ER-1 license specifically state that a contractor may not
,contract for more than four dwelling units in any single building or structure. This limitation is a
critical aspect of the license's scope .
4. Which edition of the National Electrical Code (NEC) is currently adopted by the state of New
Mexico for its electrical code?
A) 2017 NEC
B) 2020 NEC
C) 2023 NEC
D) 2026 NEC
Correct Answer: B) 2020 NEC
Rationale: New Mexico adopted the 2020 edition of the National Electrical Code (NFPA 70), which
became effective on March 28, 2023. This is the primary technical standard for electrical installations
in the state and is the basis for the ER-1 exam .
5. A technician is installing a new 120-volt branch circuit for a bathroom vanity light. Per NEC 210.8,
what type of protection is required for the receptacle supplying this fixture?
A) Ground-Fault Circuit-Interrupter (GFCI) protection only.
B) Arc-Fault Circuit-Interrupter (AFCI) protection only.
C) Both GFCI and AFCI protection are required.
D) Neither GFCI nor AFCI protection is required for a dedicated lighting circuit.
Correct Answer: A) Ground-Fault Circuit-Interrupter (GFCI) protection only.
Rationale: The NEC requires that all receptacles in a bathroom be GFCI-protected. While AFCI
protection is required for many dwelling unit circuits, it is not mandatory for a circuit that supplies
only a single bathroom vanity light, as the requirement is for outlets in specific rooms, not all circuits .
6. During a residential inspection, an electrical contractor is installing a new 20-ampere branch circuit
in a kitchen to supply countertop receptacles. The inspector notes a violation because the circuit
lacks proper protection. What protection is the inspector likely citing?
A) Lack of a dedicated circuit for the refrigerator.
B) Absence of Ground-Fault Circuit-Interrupter (GFCI) protection.
C) Absence of Arc-Fault Circuit-Interrupter (AFCI) protection.
D) Missing tamper-resistant (TR) receptacles.
Correct Answer: B) Absence of Ground-Fault Circuit-Interrupter (GFCI) protection.
Rationale: NEC 210.8(A)(6) mandates GFCI protection for all 125-volt, 15- and 20-ampere receptacles
in a kitchen. The inspector is likely citing the lack of GFCI protection, a common violation in areas near
water .
7. An installer is feeding a sub-panel in a detached garage from a 30-ampere breaker. Using copper
conductors with a 75°C rating, what is the minimum conductor size required per NEC Table
310.15(B)(16)?
A) 10 AWG
B) 8 AWG
, C) 6 AWG
D) 4 AWG
Correct Answer: B) 8 AWG
Rationale: For a 30-ampere feeder, the conductor must have an ampacity of at least 30 amperes.
According to NEC Table 310.15(B)(16), an 8 AWG copper conductor at 75°C is rated for 40 amperes,
making it suitable for this application .
8. According to the NEC, what is the primary function of an Arc-Fault Circuit-Interrupter (AFCI)?
A) To protect people from electric shock by detecting ground faults.
B) To protect against overloads and short circuits.
C) To detect and mitigate the effects of series or parallel arcing that can cause fires.
D) To provide surge protection for sensitive electronic equipment.
Correct Answer: C) To detect and mitigate the effects of series or parallel arcing that can cause fires.
Rationale: AFCIs are designed to protect against electrical fires by detecting hazardous arcing
conditions in wiring. Unlike GFCIs, which protect against shock, AFCIs are a fire-prevention device .
9. An electrician is supporting a new run of Type NM-B (Romex) cable through unfinished basement
joists. Per NEC 334.30, what is the maximum interval at which the cable must be secured?
A) 3 feet
B) 4 ½ feet
C) 6 feet
D) 8 feet
Correct Answer: B) 4 ½ feet
Rationale: NEC 334.30 requires that Type NM cable be secured at intervals not exceeding 4 ½ feet.
This ensures the cable is properly supported and protected from physical damage .
10. Which of the following is NOT a recognized grounding electrode for a residential grounding
system per the NEC?
A) A metal underground water pipe in direct contact with the earth for 10 feet or more.
B) A concrete-encased electrode (Ufer ground).
C) A ground rod.
D) Aluminum siding.
Correct Answer: D) Aluminum siding.
Rationale: The NEC lists specific items that qualify as grounding electrodes, including metal water
pipes, concrete-encased electrodes, and ground rods. Aluminum siding is not on this list and is
therefore not an acceptable grounding electrode .
11. A homeowner is installing a new 15-ampere, 120-volt circuit for a living room. Per NEC 240.4(D),
what is the maximum overcurrent protection device rating for 14 AWG copper conductors?
A) 10 amperes
B) 15 amperes
EXAM COMPLETE EXAM QUESTIONS AND VERIFIED
ANSWERS | 2026–2027 LATEST UPDATE | GUARANTEED
PASS | DETAILED RATIONALES | FULL STUDY GUIDE | EXAM
PREP | PRACTICE TEST | CERTIFICATION PREPARATION
1. According to the New Mexico Administrative Code (NMAC 14.10.4), which of the following best
describes the scope of work permitted under an ER-1 Residential Electrical Wiring license?
A) Any residential and commercial electrical work, including hotels and motels.
B) One- and two-family dwellings only, with multi-family units limited to ground-floor units with no
occupancies above or below.
C) All multi-family dwellings without restriction, regardless of the number of floors.
D) Only new construction of single-family homes and duplexes.
Correct Answer: B) One- and two-family dwellings only, with multi-family units limited to ground-
floor units with no occupancies above or below.
Rationale: The NMAC explicitly restricts the ER-1 license to one- and two-family dwelling units and
multi-family dwellings where all units are on the ground floor with no occupancies above or below. It
prohibits commercial work such as motels and hotels. This defines the legal scope for a residential
electrical contractor in New Mexico .
2. What is the minimum work experience required for an individual to qualify as the qualifying party
for an ER-1 Residential Electrical Wiring license in New Mexico?
A) 1 year (2,000 hours)
B) 2 years (4,000 hours)
C) 3 years (6,000 hours)
D) 4 years (8,000 hours)
Correct Answer: B) 2 years (4,000 hours)
Rationale: The New Mexico Construction Industries Division (CID) requires the qualifying party for an
ER-1 license to provide proof of at least two years, or 4,000 hours, of verifiable experience in
residential electrical wiring. This is a key eligibility requirement .
3. What is the maximum number of dwelling units an ER-1 contractor may contract for in a single
building or structure?
A) 2
B) 3
C) 4
D) 6
Correct Answer: C) 4
Rationale: The regulations governing the ER-1 license specifically state that a contractor may not
,contract for more than four dwelling units in any single building or structure. This limitation is a
critical aspect of the license's scope .
4. Which edition of the National Electrical Code (NEC) is currently adopted by the state of New
Mexico for its electrical code?
A) 2017 NEC
B) 2020 NEC
C) 2023 NEC
D) 2026 NEC
Correct Answer: B) 2020 NEC
Rationale: New Mexico adopted the 2020 edition of the National Electrical Code (NFPA 70), which
became effective on March 28, 2023. This is the primary technical standard for electrical installations
in the state and is the basis for the ER-1 exam .
5. A technician is installing a new 120-volt branch circuit for a bathroom vanity light. Per NEC 210.8,
what type of protection is required for the receptacle supplying this fixture?
A) Ground-Fault Circuit-Interrupter (GFCI) protection only.
B) Arc-Fault Circuit-Interrupter (AFCI) protection only.
C) Both GFCI and AFCI protection are required.
D) Neither GFCI nor AFCI protection is required for a dedicated lighting circuit.
Correct Answer: A) Ground-Fault Circuit-Interrupter (GFCI) protection only.
Rationale: The NEC requires that all receptacles in a bathroom be GFCI-protected. While AFCI
protection is required for many dwelling unit circuits, it is not mandatory for a circuit that supplies
only a single bathroom vanity light, as the requirement is for outlets in specific rooms, not all circuits .
6. During a residential inspection, an electrical contractor is installing a new 20-ampere branch circuit
in a kitchen to supply countertop receptacles. The inspector notes a violation because the circuit
lacks proper protection. What protection is the inspector likely citing?
A) Lack of a dedicated circuit for the refrigerator.
B) Absence of Ground-Fault Circuit-Interrupter (GFCI) protection.
C) Absence of Arc-Fault Circuit-Interrupter (AFCI) protection.
D) Missing tamper-resistant (TR) receptacles.
Correct Answer: B) Absence of Ground-Fault Circuit-Interrupter (GFCI) protection.
Rationale: NEC 210.8(A)(6) mandates GFCI protection for all 125-volt, 15- and 20-ampere receptacles
in a kitchen. The inspector is likely citing the lack of GFCI protection, a common violation in areas near
water .
7. An installer is feeding a sub-panel in a detached garage from a 30-ampere breaker. Using copper
conductors with a 75°C rating, what is the minimum conductor size required per NEC Table
310.15(B)(16)?
A) 10 AWG
B) 8 AWG
, C) 6 AWG
D) 4 AWG
Correct Answer: B) 8 AWG
Rationale: For a 30-ampere feeder, the conductor must have an ampacity of at least 30 amperes.
According to NEC Table 310.15(B)(16), an 8 AWG copper conductor at 75°C is rated for 40 amperes,
making it suitable for this application .
8. According to the NEC, what is the primary function of an Arc-Fault Circuit-Interrupter (AFCI)?
A) To protect people from electric shock by detecting ground faults.
B) To protect against overloads and short circuits.
C) To detect and mitigate the effects of series or parallel arcing that can cause fires.
D) To provide surge protection for sensitive electronic equipment.
Correct Answer: C) To detect and mitigate the effects of series or parallel arcing that can cause fires.
Rationale: AFCIs are designed to protect against electrical fires by detecting hazardous arcing
conditions in wiring. Unlike GFCIs, which protect against shock, AFCIs are a fire-prevention device .
9. An electrician is supporting a new run of Type NM-B (Romex) cable through unfinished basement
joists. Per NEC 334.30, what is the maximum interval at which the cable must be secured?
A) 3 feet
B) 4 ½ feet
C) 6 feet
D) 8 feet
Correct Answer: B) 4 ½ feet
Rationale: NEC 334.30 requires that Type NM cable be secured at intervals not exceeding 4 ½ feet.
This ensures the cable is properly supported and protected from physical damage .
10. Which of the following is NOT a recognized grounding electrode for a residential grounding
system per the NEC?
A) A metal underground water pipe in direct contact with the earth for 10 feet or more.
B) A concrete-encased electrode (Ufer ground).
C) A ground rod.
D) Aluminum siding.
Correct Answer: D) Aluminum siding.
Rationale: The NEC lists specific items that qualify as grounding electrodes, including metal water
pipes, concrete-encased electrodes, and ground rods. Aluminum siding is not on this list and is
therefore not an acceptable grounding electrode .
11. A homeowner is installing a new 15-ampere, 120-volt circuit for a living room. Per NEC 240.4(D),
what is the maximum overcurrent protection device rating for 14 AWG copper conductors?
A) 10 amperes
B) 15 amperes
