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A comprehensive guide for preparing for master electrician's exams #10-12. It includes 75 complete solutions to various questions covering essential electrical concepts and regulations. Designed to help individuals studying for the master electrician's exam by providing practice questions and answers.
Typology: Exams
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At carnivals and fairs, service equipment shall not be installed in a location that is accessible to unqualified persons, UNLESS the equipment ____.
A. has a voltage to ground of not more than 125 volts
B. is provided with GFCI protection
C. is lockable
D. is installed at a height of more than 6 feet - ANSWER C. is lockable
pg. 463
Where the NEC specifies that one equipment shall be "within sight from" or "within sight of" another equipment, the specified equipment is to be visible and NOT more than ____ from the other.
A. 50 feet
B. 100 feet
C. 125 feet
D. 200 feet - ANSWER A. 50 feet
pg. 37
As a general rule, where a cable is installed parallel to framing members, the cable shall be installed so that the nearest edge of the cable is NOT less than ____ from the nearest edge of the framing member.
A. 3/4 in.
B. 1 in.
C. 1 1/4 in.
D. 1 1/2 in. - ANSWER C. 1 1/4 in.
pg. 141
Generally, how many grounded conductors are permitted to be terminated under an individual terminal within a switchboard or panelboard where the equipment operates at less than 1,000 volts?
A. four
B. three
C. two
D. one - ANSWER D. one
pg. 274
The service equipment provided for a mobile home shall be located in sight from and NOT more than ____ from the exterior wall of the mobile home it serves.
A. 50 feet
B. 30 feet
C. 75 feet
D. 100 feet - ANSWER B. 30 feet
pg. 479
What is the MAX. number of size 1/0 AWG THH/THWN copper current-carrying conductors allowed by the NEC at any cross-sectional area of a 4in. x 4 in. metallic wireway?
1,150 VA garbage disposer
700 VA attic fan
1,920 VA garage door opener
The demand load, in VA, on the ungrounded (line) service entrance conductors for the listed appliances is ____ when applying the general method of calculations for dwelling units.
pg. 77
Nonmetallic cable trays shall be made of ____ material.
A. fire-resistant
B. waterproof
C. fire-proof
D. flame-retardant - ANSWER D. flame-retardant
pg. 243
Switches are to be located a horizontal distance of LEAST ____ from the inside walls of an indoor placed spa or hot tub.
A. 4 feet
B. 5 feet
C. 8 feet
D. 10 feet - ANSWER B. 5 feet
pg. 575
Direct buried cables installed under an open field vacant property must have a MIN. cover depth of ____ when the applied voltage is not more than 600 volts.
A. 24 inches
B. 18 inches
C. 12 inches
D. 30 inches - ANSWER A. 24 inches
pg. 143
Shore power for boats docked in marinas and boatyards shall be provided by single receptacles that are of the locking- and grounding-type, mounted at least 12 inches above the deck surface, and rated NOT less than ____.
A. 50 amperes
B. 40 amperes
C. 30 amperes
D. 20 amperes - ANSWER C. 30 amperes
pg. 502
For electrical systems over 1000 volts, where pulls of conductors in junction boxes are being made, the length of the box shall NOT be less than ____ the outside diameter of the largest shielded or lead- covered conductor or cable entering the box.
A. 8 times
B. 12 times
C. 32 times
C. 4 feet
D. 5 feet - ANSWER D. 5 feet
pg. 225
At LEAST ____ of free conductor, measured from the point in the box where it emerges from its raceway, shall be left at each junction box or device box for splices or connections to devices.
A. 4 inches
B. 6 inches
C. 8 inches
D. 12 inches - ANSWER B. 6 inches
pg. 146
Where fixed wiring above bulk storage tanks is installed in PVC conduit, the PVC shall be ____.
A. Schedule 20
B. Schedule 40
C. Schedule 80
D. Schedule 100 - ANSWER C. Schedule 80
pg. 420
Electrical installations which are controlled by lock(s) or other approved means, shall be considered to be accessible to ____.
A. personnel with a key
B. qualified persons only
C. personnel with authority
D. building inspectors and first responders - ANSWER B. qualified persons only
pg. 52
The size of an equipment grounding conductor of the wire type is based on the ____.
A. line voltage
B. conductor resistance
C. line inductance
D. the rating of the branch-circuit, short-circuit, and ground-fault protective device - ANSWER D. the rating of the branch-circuit, short-circuit, and ground-fault protective device
pg. 132, 133
The NEC mandates expansion fittings for rigid PVC conduit shall be provided to compensate for thermal expansion. In an environment where the normal annual change in temperature is 100 deg. F, and the length of the PVC is 100 feet, how much allowance for thermal expansion must be considered?
A. 4.06 inches
B. 6.08 inches
C. 3.04 inches
D. 8.11 inches - ANSWER A. 4.06 inches
pg. 212
Where an enclosure housing a motor controller is located outdoors and subjected to exposure to heavy rain, sleet and snow, the enclosure must have a MIN. listing as a ____ enclosure.
A. Type 1
B. Type 3
B. 4 feet
C. 5 feet
D. 6 feet - ANSWER A. 3 feet
pg. 211
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.
A. Class I
B. Class II
C. Class III
D. Class IV - ANSWER C. Class III
pg. 363
A copper-clad steel rod type grounding electrode shall be at LEAST ____ in diameter.
A. 3/8 in.
B. 1/2 in.
C. 5/8 in.
D. 3/4 in. - ANSWER C. 5/8 in.
pg. 120
Given: A single phase, 120/240-volt service of a single-family dwelling has a 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 ____.
A. 2 ft. 6 in.
B. 3 ft.
C. 3 ft. 6 in.
D. 4 ft. - ANSWER B. 3 ft.
pg. 50
Tap conductors for a recessed luminaire shall be in a suitable raceway or Type AC or MC cable having a length NOT to exceed ____.
A. 4 ft.
B. 6 ft.
C. 5 ft.
D. 8 ft. - ANSWER B. 6 ft.
pg. 283
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.
A. 10 inches
B. 8 inches
C. 12 inches
D. 6 inches - ANSWER D. 6 inches
pg. 199
When used as a direct buried cable, which of the following wiring methods is permitted for use to supply a water well pump located 50 feet from a dwelling?
A. 10 feet
B. 6 feet
C. 7 feet
D. 8 feet - ANSWER C. 7 feet
pg. 293
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 ____.
A. is required to be located within 100 ft. from the equipment
B. may be connected to the line side of the equipment disconnecting means, provided the receptacle is equipped with GFCI protection
C. shall be located on the same level and within 25 ft. of the equipment
D. is permitted to be connected to the load side of the equipment disconnecting means, if within 10 ft. of the equipment and GFCI protected - ANSWER C. shall be located on the same level and within 25 ft. of the equipment
pg. 70
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?
A. 180 amperes
B. 196 amperes
C. 416 amperes
D. 334 amperes - ANSWER B. 196 amperes
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.
pg. 260
In metal raceways or enclosures, all conductors of feeder using a common neutral shall be enclosed within the same raceway or enclosure, with a MAX. of ____ sets of 3-wire feeders permitted to utilize a common neutral.
A. two
B. three
C. four
D. five - ANSWER B. three
pg. 72
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.
A. 1/2 in.
B. 3/8 in.
C. 3/4 in.
D. 1/4 in. - ANSWER D. 1/4 in.
pg. 179
pg. 161
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 ____.
A. voltage rating
B. power rating
C. temperature rating
D. insulation rating - ANSWER C. temperature rating
pg. 32
Where a building or structure is supplied by more than one service from the local utility company:
A. a fire pump shall be installed
B. a permanent plaque shall be installed at each service disconnect location denoting all other services
C. an optional standby system shall be installed
D. all of the above shall be installed - ANSWER B. a permanent plaque shall be installed at each service disconnect location denoting all other services
pg. 89
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.
A. five
B. three
C. four
D. six - ANSWER A. five
pg. 367
Except as otherwise permitted in the NEC, where the service entrance conductors for a commercial building or an industrial facility are size 250 kcmil aluminum with XHHW insulation, what MIN. size copper grounding electrode conductor is required?
pg. 133
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.
A. only AFCI
B. only GFCI
C. both AFCI and GFCI
D. only LCDI - ANSWER B. only GFCI
pg. 62
For track lighting in other than dwelling units, or guest rooms of hotels and motels, a load of ____ shall be calculated for every 2 ft. of lighting track or fraction thereof.
C. over steps of a stairway
D. under a mezzanine - ANSWER C. over steps of a stairway
pg. 103
For the purpose of determining conductor fill in a device box, a three-way switch is counted as equal to ____ conductor(s), based on the largest conductor connected to the switch.
A. one
B. two
C. three
D. four - ANSWER B. two
pg. 183
A transformer vault is required to be provided with a door sill or curb with a height of NOT less than ____.
A. 6 in.
B. 8 in.
C. 2 in.
D. 4 in. - ANSWER D. 4 in.
pg. 348
Single phase, 125-volt, 15- and 20-ampere receptacle outlets installed in floors of dwelling units shall not be counted as part of the required number of receptacle outlets, if they are located more than ____ from the wall.
A. 18 in.
B. 12 in.
C. 30 in.
D. 24 in. - ANSWER A. 18 in.
pg. 68
When exceptions are not applicable, where a feeder serves a continuous load of 240 amperes the overcurrent protection device protecting this circuit shall have a MIN. ampere rating of ____.
A. 250 amperes
B. 275 amperes
C. 300 amperes
D. 325 amperes - ANSWER C. 300 amperes
pg. 71
Grounding conductors and bonding jumpers shall NOT be connected by ____.
A. exothermic welding
B. pressure connectors
C. machine screw-type fasteners
D. sheet metal screws - ANSWER D. sheet metal screws
pg. 113
Determine the initial standard size time-delay fuses permitted for branch-circuit, short-circuit and ground-fault protection for a 50 hp, 3 phase, 460-volts, induction type motor with a FLA rating of 61 amperes marked on the nameplate. Hint: use only one exception.
A. 100 amperes