Unit 11: General Practice Flashcards
Strengthen electrical knowledge, apply NEC updates, and reinforce test-taking strategies. (25 cards)
Fill in the blank:
PVC conduit shall be securely fastened within _________ of each outlet box, junction box, device box, conduit body, or other conduit termination box.
3 feet
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A hazardous location where easily ignitable fibers or materials producing combustible flyings are handled, manufactured, or used, but where they are not likely to be in suspension in the air in quantities sufficient to produce ignitable mixtures is recognized as a _________ location in the NEC®.
Class III
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A copper-clad steel rod type grounding electrode shall be at least _________ in diameter.
5/8 in
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Given: A single-phase, 120/240-volt service of a single-family dwelling hasa chain-link metal fence opposite exposed live parts of the service equipment. The required depth of the working space in front of the service equipment must be at least _________.
3 feet
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Tap conductors for a recessed luminaire shall be in a suitable raceway orType AC or MC cable having a length not to exceed _________.
6 feet
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Where exposed Type NM cable passes through a floor, the cable shall be protected from physical damage by an approved means extending at least _________ above the floor.
6 in.
When used as a direct buried cable, which wiring methods is permitted for use to supply a water well pump located 50 feet from a dwelling?
Type UF cable
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Given: The supply to a portable switchboard on a stage shall be by means of listed extra-hard usage cords or cables. Single-conductor portable supply cable sets used for this purpose shall not be smaller than _________.
2 AWG
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The minimum clearance for overhead feeder conductors, less than 1,000 volts, that pass above commercial areas subject to truck traffic is _________.
18 feet
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In regard to fixed electric space-heaters, factory-assembled non heating leads of heating cables, if any, shall be at least _________ in length.
7 feet
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Where the heating, air-conditioning or refrigeration equipment is installed on the roof of a commercial, industrial, or a multifamily apartment building, a single-phase, 125-volt, 15- or 20-ampere rated receptacle outlet _________.
shall be located on the same level and within 25 ft. of the
equipment
Given: An existing 150 kVA transformer with a 208Y/120-volt, 3-phase,secondary has a full-load current of 220 amperes per phase. What approximate additional single-phase load, per phase, may be added to the secondary side of the transformer?
196 amperes
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The conductors in multiconductor portable cables, of over 600 volts nominal, used to connect mobile equipment and machinery, shall be at least size _________ copper or larger and employ flexible stranding.
12 AWG
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In metal raceways or enclosures, all conductors of feeders using a common neutral shall be enclosed within the same raceway or enclosure,with a maximum of _________ sets of 3-wire feeders permitted to utilize a common neutral.
three
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When installing surface-type metal panelboards, cabinets, disconnects or meter socket enclosures in damp or wet locations they shall be mounted so there is at least _________ airspace between the enclosure and the wall or other supporting surface.
1/4 in
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On a 4-wire, 3-phase, wye circuit where more than _________ of the load consists of nonlinear loads such a fluorescent lighting, there are harmonic current present in the neutral conductor and the neutral conductor shall be considered to be a current-carrying conductor.
50%
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Where direct-buried conductors emerge from below grade and extend upa pole, the conductors must be protected by raceways up to a height of 8 feet above finished grade and in no case shall protection be required to exceed _________ below finished grade.
18 in.
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Given: After all demand factors have been taken into consideration, small office building with a single-phase, 120/240-volt electrical system has a demand load of 35,000 watts. The minimum size copper conductors withTHW insulation required for the ungrounded (line) service entrance conductors is _________.
1/0 AWG
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According to the NEC®, the ampacity of a conductor is the current, in amperes, that the conductor can carry continuously under the conditions of use without exceeding its _________.
temperature rating
What is required when a building or structure receives multiple services from the local utility company?
A permanent plaque shall be installed at each service disconnect location denoting all other services.
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In Class I, Division 1 locations, all threaded conduit and fittings referred as National Standard Pipe Taper (NPT) thread that are entries into explosion proof equipment shall be made up with at least _________ fully engaged threads.
five
Unless otherwise permitted by the NEC®, what is the minimum required size for a copper grounding electrode conductor when the service entrance conductors for a commercial building or industrial facility are 350 kcmil aluminum with XHHW insulation?
2 AWG
Fill in the blank:
Where a wall-mounted central vacuum system is cord-and-plug connected to a single-phase, 125-volt, 20-ampere receptacle located in an attached garage of a residence, the receptacle shall be provided with _________ protection.
only GFCI
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For track lighting in other than dwelling units, or guest rooms of hotels and motels, a load of _________ shall be calculated for every two (2) feet of lighting track or fraction thereof.
150 VA
