NEC 2023 Code Questions Practice Test 3

Question 1: If the conduit is placed in hazardous locations , it must be made .................... to prevent sparking when fault current flow through it.

• wrench tight
• sealed
• bonded
• rugged plastic

NEC Reference: NEC 500.8(E)

Question 2: What are the maximum allowable service dis connectors consist for each service?

• 4
• 2
• 6
• 8

NEC Reference: NEC 230.71(A)

Question 3: What is the smallest rating plug fuse that is used for residential 120 volts branch circuit?

• 15 amperes
• 20 amperes
• 12 amperes
• 18 amperes

NEC Reference: NEC 240.6(A)

Question 4: What is the voltage drop of two 10 AWG THWN conductors that supply 16 amperes 115 volts load located 50 feet from the source?

• 1.92 volts
• 0.96 volts
• 2.4 volts
• 1.8 volts

Question 5: What is the minimum volt ampere rating of a 110,000 square foot school?

• 330 KVA
• 220 KVA
• 165 KVA
• 440 KVA

NEC Reference: NEC 220.12

Question 6: A disconnecting means should be visibly located from a motor not more than .............. distance.

• 50 feet
• 40 feet
• 55 feet
• 60 feet

Question 7: A 4800 watts electric motor is connected to 240 volts single phase supply, 2 wire circuit. what is the minimum size THW conductor that is required to supply the load?

• 14 AWG
• 12 AWG
• 10 AWG
• 8 AWG

NEC Reference: NEC 424.3(B)

Question 8: What is the minimum allowable 3 wire service entrance conductor rating for a single family dwelling unit?

• 100 amperes
• 125 amperes
• 150 amperes
• 75 amperes

NEC Reference: NEC 230.42(B)

Question 9: An electric heater with a resistance of 18 ohms draws a current of 7 amperes. what is the minimum wattage of electric heater?

• 882 watts.
• 764 watts
• 126 watts
• 922 watts

Question 10: what is the maximum over current device rating that is allowed to placed  to protect panel board instrumentation circuit?

• 30 amperes
• 15 amperes
• 20 amperes
• 10 amperes

NEC Reference: NEC 408.52

Question 11: AFCI protection is required for 120 volt, 15 and 20 ampere branch circuits supplying outlets in which occupancy, in addition to dwelling units?

• Hotel and motel guest rooms/suites
• Industrial warehouses only
• No other occupancy requires AFCI
• Outdoor parking lots only

NEC Reference: NEC 210.12(C)

Question 12: Overhead conductors are subject to increased clearance requirements when installed near a swimming pool, to reduce the risk of contact by:

• Pool equipment, ladders, and people at the pool
• It has no relevance to swimming pools
• Only lightning strikes
• Only birds landing on the wire

NEC Reference: NEC 225.19(C)

Question 13: Each ungrounded service conductor must be protected by an overcurrent device with a rating or setting:

• Not higher than the conductor ampacity (with a limited exception)
• At least double the conductor ampacity
• No overcurrent protection is required at services
• Exactly half the conductor ampacity

NEC Reference: NEC 230.90(A)

Question 14: Under the small conductor rule, 14 AWG copper conductors are limited to a maximum standard overcurrent device rating of:

• 15 amperes
• 20 amperes
• 25 amperes
• 30 amperes

NEC Reference: NEC 240.4(D)(3)

Question 15: Where a service consists of multiple disconnects fed from one set of service-entrance conductors, the connection of the grounded conductor to the grounding electrode system must be made:

• At only one point
• At every disconnect separately
• It does not matter how many points are used
• No connection is ever made

NEC Reference: NEC 250.24(A)(4)

Question 16: In spaces used for environmental air (other than ducts and plenums specifically fabricated for that purpose), wiring methods are generally limited to:

• Metal raceways or specific metal-clad cable types
• Any type of nonmetallic cable, without restriction
• Bare open conductors
• No wiring is ever permitted in air handling spaces

NEC Reference: NEC 300.22(C)

Question 17: An ungrounded (hot) conductor must NOT be identified using which of the following colors, since they are reserved for grounded and grounding conductors?

• White or gray
• Black
• Red
• Blue

NEC Reference: NEC 200.6

Question 18: Boxes installed in wet locations must be listed for the purpose, and enclosures for switches or receptacles must additionally be:

• Weatherproof so moisture does not enter or accumulate
• Left open with no cover
• Made only of untreated wood
• It does not matter in wet locations

NEC Reference: NEC 314.15

Question 19: Intermediate metal conduit (IMC) must generally be supported at intervals not exceeding:

• 5 feet
• 10 feet
• 15 feet
• 20 feet

NEC Reference: NEC 342.30

Question 20: Liquidtight flexible metal conduit (LFMC) must generally be secured within 12 inches of every box or fitting and supported at intervals not exceeding:

• 2 feet
• 4 1/2 feet
• 10 feet
• 15 feet

NEC Reference: NEC 350.30

Question 21: An AC general-use snap switch controlling a tungsten-filament lamp load must be rated for tungsten-filament loads, or rated in amperes not less than:

• T rated, or otherwise rated for tungsten-filament loads
• Any standard switch works with no restriction
• A switch is never permitted for this load
• Only DC-rated switches are permitted

NEC Reference: NEC 404.14(A)

Question 22: A faceplate for a switch or receptacle installed in a damp or wet location must be installed so as to be:

• Fitted closely against the mounting surface
• Left with a large visible gap
• Removed entirely for airflow
• It does not matter in wet locations

NEC Reference: NEC 406.9

Question 23: A fluorescent luminaire supplied by a multiwire branch circuit and containing double-ended lamp ballast(s) must have a disconnecting means to disconnect:

• All ungrounded conductors supplying the ballast(s)
• Only the grounded (neutral) conductor
• No disconnect is ever required for fluorescent fixtures
• Only the equipment grounding conductor

NEC Reference: NEC 410.130(G)

Question 24: NEC 422.5(A) requires factory-installed GFCI protection for cord-and-plug-connected appliances used in damp or wet locations, including which of the following?

• High-pressure spray washing machines
• Table lamps
• Standard desktop computers
• Ceiling fans

NEC Reference: NEC 422.5(A)

Question 25: Embedded heating cables must not be spliced in the field except with:

• Identified splicing devices or kits
• Ordinary wire nuts
• Electrical tape alone
• Field splices are never permitted, even with a kit

NEC Reference: NEC 424.44(C)

Question 26: A motor circuit disconnecting means is generally permitted to be a motor-circuit switch rated in horsepower, a molded-case circuit breaker, a molded-case switch, or:

• An instantaneous-trip circuit breaker in a listed combination controller
• A standard wall light switch
• No disconnect type is ever acceptable
• A telephone jack

NEC Reference: NEC 430.109(A)

Question 27: When the maximum branch-circuit short-circuit and ground-fault protective device rating calculated for multimotor equipment does not correspond to a standard rating, which rating is permitted to be used?

• The next lower standard rating
• The next higher standard rating, always
• No standard rating may ever be substituted
• A rating of exactly 15 amperes, regardless of load

NEC Reference: NEC 440.22(C)

Question 28: An autotransformer supplying a branch circuit must be provided with individual overcurrent protection, generally set at not more than what percentage of the rated full-load input current?

• 125 %
• 250 %
• 400 %
• No protection is required

NEC Reference: NEC 450.4

Question 29: Equipment for use in a Class I hazardous location must be marked to show the operating temperature, or the identification number, in relation to the:

• Ignition temperature of the specific gas or vapor present
• The color of the equipment housing
• The installer's preferred temperature
• No temperature marking is ever required

NEC Reference: NEC 500.9

Question 30: Outlets used to supply power to boat hoists in a marina or boatyard must be protected by:

• GFCI protection
• No special protection
• AFCI protection only
• A surge arrestor only

NEC Reference: NEC 555.13