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These 10 free MT-ME questions are organized by exam domain, so you can see how each part of the Montana Master Electrician License Exam blueprint is tested. Reveal the answer and explanation under each question.
Domain 1: National Electrical Code
Question 1
A packaged air-conditioning unit is marked minimum circuit ampacity (MCA) 28 A and maximum overcurrent protection (MOCP) 45 A. Its listing permits an inverse-time circuit breaker. The installer uses 10 AWG copper THWN-2 conductors, 75°C terminals, and a 45 A breaker. The conductor ampacity is 35 A, with no adjustment or correction required. A reviewer objects that 10 AWG copper normally has a 30 A overcurrent limit. Under the 2020 NEC, how should this objection be resolved?
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Correct answer: C - Accept the conductor and breaker sizing; Article 440 permits this nameplate-based combination.
Question 2
At a newly built detached workshop, a PVC raceway contains a 120/240 V feeder with two ungrounded conductors and a neutral, but no equipment grounding conductor. The workshop disconnect has its neutral bonded to the enclosure, and two properly installed ground rods are connected there. The feeder originates downstream of the service disconnect. Which correction establishes the required grounding and bonding arrangement under the 2020 NEC?
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Correct answer: B - Add a feeder equipment grounding conductor; isolate the neutral and bond the enclosure and electrodes to that grounding conductor.
Question 3
An inspector cites the 2020 NEC when calling for 42 in. of working-space depth in front of a 208Y/120 V panelboard facing a concrete wall. Field measurement shows 39 in. from the panel enclosure to that wall. Required width, height, access, and door opening are satisfied, and no special condition increases the required depth. Which assessment of the NEC minimum is correct?
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Correct answer: C - 39 in. is adequate because the voltage to ground is 120 V, requiring 36 in.
Question 4
A Montana installer proposes a 50 A, 125/250 V receptacle specifically for cord-and-plug-connected electric vehicle charging in a dry residential garage. The installer cites Montana's deletion of 250 V receptacles from NEC 210.8(A) as the reason to omit GFCI protection. Applying Montana's amendments to the 2020 NEC, which requirement controls this installation?
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Correct answer: D - Article 625 independently requires GFCI protection for this EV-charging receptacle.
Question 5
A noncontinuous 54 A load will be supplied by copper THWN-2 conductors. Nine current-carrying conductors occupy the raceway for its full 80 ft length, the ambient temperature is 43°C, and all terminals are rated 75°C. The conductor-count factor is 70%; the ambient factors are 0.82 for 75°C insulation and 0.87 for 90°C insulation. Table ampacities for 8, 6, 4, and 3 AWG copper are respectively 50, 65, 85, and 100 A at 75°C, and 55, 75, 95, and 115 A at 90°C. Which is the smallest conductor that satisfies the load and terminal limits?
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Correct answer: A - 4 AWG
Domain 2: General Trade Knowledge & Theory
Question 6
Lights on one side of a 120/240 V dwelling service brighten while lights on the other side dim as appliances cycle. A qualified electrician records 91 V from L1 to neutral, 149 V from L2 to neutral, and a steady 240 V from L1 to L2 at the service equipment. Which fault best accounts for this combination?
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Correct answer: A - A high-resistance connection in the service neutral.
Question 7
A conveyor uses conventional three-wire control: a normally closed STOP contact and overload contact are in series with the starter coil, and a normally open auxiliary contact parallels the momentary START button. The motor runs normally while START is held, but stops immediately when it is released. Recorded coil voltage is rated voltage while START is held and zero after release. The STOP and overload contacts have been verified closed. Where should the electrician focus the deenergized continuity checks?
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Correct answer: B - The auxiliary seal-in contact or its wiring.
Question 8
A qualified electrician must make an authorized 480 V measurement from an ungrounded service conductor to ground at the utility service entrance, a CAT IV location. The work plan addresses shock and arc-flash protection. Considering both measurement category and voltage, which meter marking is suitable? Assume matching leads and no additional ratings beyond those shown.
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Correct answer: C - CAT IV 600 V
Domain 3: Major Load Calculations
Question 9
For a dwelling eligible for the optional calculation in 2020 NEC 220.82, the complete general-load group is 42,000 VA before demand factors. This includes all applicable floor-area, small-appliance, laundry, appliance, and motor loads, but excludes heating and cooling. Five separately controlled electric space-heating units total 18,000 VA; none is a thermal-storage unit or expected to run continuously at full rating. Air conditioning is 9,600 VA, and controls prevent heating and cooling from operating together. What is the total calculated service load?
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Correct answer: D - 32,400 VA
Question 10
One feeder supplies three ordinary continuous-duty, three-phase motors that can run together. At 460 V, their NEC table full-load currents are 40 A, 27 A, and 14 A; the corresponding nameplate currents are 35 A, 24 A, and 12 A. No other loads or special motor exceptions apply. Before ambient-temperature correction or conductor-count adjustment, what minimum feeder conductor ampacity is required?
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Correct answer: A - 91 A
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