Journeyman Electrician #4

Class 3 single-conductors shall NOT be smaller than _____. a) 18 AWG b) 16 AWG c) 14 AWG d) 20 AWG

A: 18 AWG Ref: 725.179(H)

Household-type appliances with surface heating elements having a MAXIMUM demand of more than _____ amperes, shall have its power supply subdivided into two or more circuits. a) 60 b) 50 c) 40 d) 30

A: 60 Ref: 422.11(B)

A surge-protective device (SPD) is a protective device for _____. a) limiting transient voltage by diverting or limiting surge current b) limiting transient voltage by absorbing and storing excessive surge current c) switching transient voltage back to the line side of the service transformer d) none of these

A: limiting transient voltage by diverting or limiting surge current Ref: Art. 100

For enclosing a mobile home supply cord, what is the MAXIMUM trade size conduit permitted between the branch-circuit panelboard of a mobile home and the underside of a mobile home floor? a) 1 inch b) 1 1⁄4 inch c) 1 1⁄2 inch d) 2 inch

B: 1 1⁄4 inch Ref: 550.10(G)

Enclosures in a Class I, Division 1, location containing components that have arcing devices must have an approved seal located within _____ of each conduit run entering or leaving such enclosures. a) 12 inches b) 18 inches c) 24 inches d) 30 inches

B: 18 inches Ref: 501.15(A)(1)

Given: an office building has a 208Y/120 volt, three-phase service with a balanced net computed load of 90 kVA. What is the current each ungrounded conductor carries at full load? a) 188 amperes b) 250 amperes c) 433 amperes d) 750 amperes

B: 250 amperes Ref: Trade and General Knowledge; 3-Phase Current Formula Sol: I = Power / (E x 1.732) I = (90 kVA x 1,000) / (208 x 1.732) I = 90,000 / 360.25 = 250 amperes

According to the National Electrical Code, what are the two mandatory branches of the hospital emergency system? a) The emergency branch and the standby branch. b) The life safety branch and the critical branch. c) The normal branch and the alternate branch. d) The essential branch and the non-essential branch.

B: The life safety branch and the critical branch Ref: 517.31

Given: an existing metal junction box has a volume of 27 cubic inches and contains a total of six size 12 AWG wires. Additional wires of size 10 AWG need to be added in the box. No grounding conductors, devices or fittings are contained in the box. What is the MAXIMUM number of size 10 AWG conductors that may be added to this box? a) two b) five c) six d) eight

B: five Ref: Tbl. 314.16(B)

When installed on the service of a building or structure, a type 2 SPD (TVSS) shall be connected _____. a)on the line side of the service disconnect overcurrent device b) on the load side of the service disconnect overcurrent device c) on the meter housing d) at the final overcurrent device

B: on the load side of the service disconnect overcurrent device Ref: 285.24(A)

Storage batteries used as a source of power for emergency systems shall be of a suitable rating and capacity to supply and maintain the total load for at LEAST _____. a) 1⁄ 2 hour b) 1 hour c) 1 1⁄ 2 hours d) 2 hours

C: 1 1⁄ 2 hours Ref: 700.12(A)

Branch circuits supplying a fixed, storage-type, electric water heater with a capacity of 120 gallons or less, shall NOT be less than _____ of the full-load current of the water heater. a) 80 percent b) 100 percent c) 125 percent d) 150 percent

C: 125 percent Ref: 422.10(A); 422.13

A disconnecting means shall be provided on the supply side of all fuses in circuits having a voltage of at LEAST _____ volts to ground. a) 120 b) 250 c) 150 d) 277

C: 150 Ref: 240.40

Ten copper THW conductors are to be installed in a 20-foot length of intermediate metal conduit (IMC); five size 1 AWG and five size 3 AWG. What is the MINIMUM allowable trade size IMC required to contain these conductors? a) 1 1⁄ 2 inches b) 2 inches c) 2 1⁄ 2 inches d) 4 inches

C: 2 1⁄ 2 inches Ref: Chpt. 9, Tbl. 4; Chpt. 9, Tbl. 5 Sol:#1 THW = 0.1901 sq. in. x 5 = 0.9505 sq. in. #3 THW = 0.1134 sq. in. x 5 = 0.567 sq. in. Total = 1.5175 sq. in.

A detached garage supplied from a dwelling with a three-wire feeder of size 4/0 AWG aluminum USE cable with a 200-ampere rated circuit breaker for overcurrent protection requires a MINIMUM size copper grounding electrode to a concrete encased electrode of _____ AWG. a) 8 b) 6 c) 4 d) 2

C: 4 Ref: 250.52(A)(3)

When grounding the structural reinforcing steel of a swimming pool, what is the smallest size grounding conductor permitted for this installation? a) 12 AWG b) 10 AWG c) 8 AWG d) 6 AWG

C: 8 AWG Ref: 680.26(B)(1)(a) and (b)

When a raceway is run from the interior to the exterior of a building, the raceway shall _____. a) be rigid metal conduit (RMC) b) be rigid polyvinyl chloride conduit (PVC) c) be sealed with an approved material d) have an explosion-proof seal

C: be sealed with an approved material Ref: 300.7(A)

Given: a size 14 AWG branch-circuit conductor protected by a 15-ampere rated circuit breaker is to serve three 20-ampere rated duplex receptacles. This branch-circuit: a) would be in compliance with the NEC if the wire was size 12 AWG. b) would be in compliance with the NEC if the circuit breaker was rated at 20 amperes. c) is not in compliance with the NEC because the receptacle outlets have a 20-ampere rating. d) is in compliance with the NEC.

C: is not in compliance with the NEC because the receptacle outlets have a 20-ampere rating. Ref: Tbl. 210.24

Surface-mounted incandescent luminaires installed on the wall above the door or on the ceiling of a clothes closet shall have a clearance of at LEAST ____ between the luminaire and the nearest point of storage. a) 6 inches b) 8 inches c) 18 inches d) 12 inches

D: 12 inches Ref: 410.16(C)(1)

The NEC considers the area around the fuel dispensing pumps at a service station to be a hazardous location. This area extends a height of 18 inches above grade, and up to a distance from the enclosure of the dispensing pump of _____. a) 5 feet b) 10 feet c) 16 feet d) 20 feet

D: 20 feet Ref: Tbl. 514.3(B)(1)

Where conduits enter a floor-standing switchboard or panelboard at the bottom, the conduits including their end fittings, shall not rise more than _____ above the bottom of the enclosure. a) 6 inches b) 4 inches c) 2 inches d) 3 inches

D: 3 inches Ref: 408.5

When driving a ground rod and solid rock is encountered, the ground rod is permitted to be buried in a trench that is at LEAST _____ deep a) 3 feet b) 4 feet c) 24 inches d) 30 inches

D: 30 inches Ref: 250.53(G)

Given: an 80-ampere, 240-volt, single-phase, load is located 200 feet from the supply panelboard and is supplied with size 3 AWG copper conductors with THHN/THWN insulation. What is the approximate voltage-drop on this circuit? (K = 12.9) a) 6.0 volts b) 4.0 volts c) 9.2 volts d) 7.84 volts

D: 7.84 volts Ref: Chpt. 9, Tbl. 8 Sol: VD = 2KID / CM VD = (2 x 12.9 x 80 amps x 200') / 52,620 CM = 7.84 volts

Which of the following wiring methods is/are approved for use for fixed wiring in an area above Class I locations in a commercial garage? a) type MI cable b) type TC cable c) type MC cable d) all of the above

D: all of the above Ref: 511.7(A)(1)

Class II locations are those that are hazardous (classified) because of the presence of _____. a) flammable gas b) ignitible fibers c) ignitible vapors d) combustible dust

D: combustible dust Ref: 500.5(C)

Where fuses are used for motor overload protection, if the supply system is a three-wire, three-phase, AC with one conductor grounded, the NEC requires at LEAST _____ fuse(s). a) zero b) one c) two d) three

D: three Ref: 430.36