Michigan Master Electrician Certification Practice Examination 2026/2027
1. A service disconnecting means for a one-family dwelling shall have a rating of not less than which
of the following?
A) 60 amperes
B) 80 amperes
C) 100 amperes
D) 125 amperes
Answer: C
Rationale: NEC 230.79(C) requires a one-family dwelling service disconnecting means to have a rating of at
least 100 amperes.
2. When grounding electrode conductors are connected to a metal underground water pipe, the
supplemental grounding electrode required by the NEC must be bonded to the water pipe within how
many feet of its entrance to the building?
A) 3 ft
B) 5 ft
C) 10 ft
D) 15 ft
Answer: B
Rationale: NEC 250.53(D)(2) requires the supplemental electrode to be bonded within 5 feet of where the
water pipe enters the building.
3. In a dwelling unit, what is the minimum clearance for overhead service conductors passing over a
roof that is not accessible to pedestrians?
A) 3 ft
B) 6 ft
C) 8 ft
D) 10 ft
Answer: C
Rationale: NEC 230.24(A) exception No. 2 allows 8 ft clearance over a roof with slope exceeding 4 in 12, but
only for a limited distance.
,4. The maximum allowable voltage drop for a combination of feeder and branch circuit conductors
supplying a sensitive electronic load is:
A) 2%
B) 3%
C) 5%
D) 10%
Answer: C
Rationale: NEC 210.19(A) Informational Note No. 4 suggests 3% for branch circuits and 5% total for feeder
and branch circuit combined.
5. A continuous load is defined by the NEC as a load where the maximum current is expected to
continue for at least:
A) 1 hour
B) 2 hours
C) 3 hours
D) 4 hours
Answer: C
Rationale: NEC 100 definition of continuous load – 3 hours or more.
6. What is the required clearance for a 480-volt open wiring on insulators above a commercial flat
roof that is subject to pedestrian traffic?
A) 8 ft
B) 10 ft
C) 12 ft
D) 15 ft
Answer: B
Rationale: NEC 225.19(A) requires 10 ft clearance over roofs subject to pedestrian traffic for circuits over
600V; for 480V, the same requirement applies.
7. A 150 kVA, 3-phase, 480-volt delta-delta transformer has a full-load primary current closest to:
A) 90 A
B) 180 A
2
,C) 210 A
D) 250 A
Answer: B
Rationale: I = 150,000 VA / (480V × √3) = 150,.4 = 180.4 A.
8. When using the standard method for dwelling unit load calculation, which demand factor applies
to the first 10 kVA of the calculated load?
A) 100%
B) 75%
C) 50%
D) 35%
Answer: A
Rationale: NEC Table 220.42 applies a 100% demand factor to the first 10 kVA of the calculated load for
dwelling units.
9. What is the maximum number of quarter-bend elbows permitted in a single run of electrical
conduit without the use of pull boxes?
A) Two quarter-bends
B) Three quarter-bends
C) Four quarter-bends
D) Five quarter-bends
Answer: B
Rationale: NEC Article 300 limits the number of quarter-bends (90-degree bends) in a single conduit run
between pull points to three.
10. A master electrician is planning a residential service upgrade from 100 amps to 200 amps. What
is the minimum copper conductor size required for the service entrance conductors?
A) #4 AWG
B) #3 AWG
C) #2 AWG
D) #1 AWG
Answer: D
Rationale: NEC Table 310.15(B)(16) specifies #1 AWG copper for a 200-ampere service at 75°C.
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, 11. According to the NEC, what is the maximum length of a flexible cord permitted for a portable
lamp?
A) 6 feet
B) 8 feet
C) 10 feet
D) 12 feet
Answer: C
Rationale: NEC Article 400 recommends a maximum length of 10 feet for flexible cords on portable lamps.
12. What is the minimum size equipment grounding conductor required for a circuit protected by a
50-ampere overcurrent device using copper?
A) #10 AWG
B) #8 AWG
C) #6 AWG
D) #4 AWG
Answer: B
Rationale: NEC Table 250.122 requires a #8 AWG copper equipment grounding conductor for a 50-ampere
overcurrent device.
13. Which statement best describes ampacity?
A) The maximum current a conductor can carry continuously without exceeding its temperature rating
B) The voltage a conductor can withstand
C) The resistance of a conductor
D) The physical diameter only
Answer: A
Rationale: Ampacity is defined as the maximum current a conductor can carry continuously under
conditions of use without exceeding its temperature rating.
14. Which statement best describes a branch circuit?
A) The circuit conductors between the final overcurrent device and the outlets
B) The service conductors only
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1. A service disconnecting means for a one-family dwelling shall have a rating of not less than which
of the following?
A) 60 amperes
B) 80 amperes
C) 100 amperes
D) 125 amperes
Answer: C
Rationale: NEC 230.79(C) requires a one-family dwelling service disconnecting means to have a rating of at
least 100 amperes.
2. When grounding electrode conductors are connected to a metal underground water pipe, the
supplemental grounding electrode required by the NEC must be bonded to the water pipe within how
many feet of its entrance to the building?
A) 3 ft
B) 5 ft
C) 10 ft
D) 15 ft
Answer: B
Rationale: NEC 250.53(D)(2) requires the supplemental electrode to be bonded within 5 feet of where the
water pipe enters the building.
3. In a dwelling unit, what is the minimum clearance for overhead service conductors passing over a
roof that is not accessible to pedestrians?
A) 3 ft
B) 6 ft
C) 8 ft
D) 10 ft
Answer: C
Rationale: NEC 230.24(A) exception No. 2 allows 8 ft clearance over a roof with slope exceeding 4 in 12, but
only for a limited distance.
,4. The maximum allowable voltage drop for a combination of feeder and branch circuit conductors
supplying a sensitive electronic load is:
A) 2%
B) 3%
C) 5%
D) 10%
Answer: C
Rationale: NEC 210.19(A) Informational Note No. 4 suggests 3% for branch circuits and 5% total for feeder
and branch circuit combined.
5. A continuous load is defined by the NEC as a load where the maximum current is expected to
continue for at least:
A) 1 hour
B) 2 hours
C) 3 hours
D) 4 hours
Answer: C
Rationale: NEC 100 definition of continuous load – 3 hours or more.
6. What is the required clearance for a 480-volt open wiring on insulators above a commercial flat
roof that is subject to pedestrian traffic?
A) 8 ft
B) 10 ft
C) 12 ft
D) 15 ft
Answer: B
Rationale: NEC 225.19(A) requires 10 ft clearance over roofs subject to pedestrian traffic for circuits over
600V; for 480V, the same requirement applies.
7. A 150 kVA, 3-phase, 480-volt delta-delta transformer has a full-load primary current closest to:
A) 90 A
B) 180 A
2
,C) 210 A
D) 250 A
Answer: B
Rationale: I = 150,000 VA / (480V × √3) = 150,.4 = 180.4 A.
8. When using the standard method for dwelling unit load calculation, which demand factor applies
to the first 10 kVA of the calculated load?
A) 100%
B) 75%
C) 50%
D) 35%
Answer: A
Rationale: NEC Table 220.42 applies a 100% demand factor to the first 10 kVA of the calculated load for
dwelling units.
9. What is the maximum number of quarter-bend elbows permitted in a single run of electrical
conduit without the use of pull boxes?
A) Two quarter-bends
B) Three quarter-bends
C) Four quarter-bends
D) Five quarter-bends
Answer: B
Rationale: NEC Article 300 limits the number of quarter-bends (90-degree bends) in a single conduit run
between pull points to three.
10. A master electrician is planning a residential service upgrade from 100 amps to 200 amps. What
is the minimum copper conductor size required for the service entrance conductors?
A) #4 AWG
B) #3 AWG
C) #2 AWG
D) #1 AWG
Answer: D
Rationale: NEC Table 310.15(B)(16) specifies #1 AWG copper for a 200-ampere service at 75°C.
3
, 11. According to the NEC, what is the maximum length of a flexible cord permitted for a portable
lamp?
A) 6 feet
B) 8 feet
C) 10 feet
D) 12 feet
Answer: C
Rationale: NEC Article 400 recommends a maximum length of 10 feet for flexible cords on portable lamps.
12. What is the minimum size equipment grounding conductor required for a circuit protected by a
50-ampere overcurrent device using copper?
A) #10 AWG
B) #8 AWG
C) #6 AWG
D) #4 AWG
Answer: B
Rationale: NEC Table 250.122 requires a #8 AWG copper equipment grounding conductor for a 50-ampere
overcurrent device.
13. Which statement best describes ampacity?
A) The maximum current a conductor can carry continuously without exceeding its temperature rating
B) The voltage a conductor can withstand
C) The resistance of a conductor
D) The physical diameter only
Answer: A
Rationale: Ampacity is defined as the maximum current a conductor can carry continuously under
conditions of use without exceeding its temperature rating.
14. Which statement best describes a branch circuit?
A) The circuit conductors between the final overcurrent device and the outlets
B) The service conductors only
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