NEC 2023 Code Questions Practice Test 4

Question 1: What is the maximum voltage drop recommended by NEC for both branch conductor and feeder conductor?

• 3 %
• 4 %
• 5 %
• 6 %

Question 2: The connected load of all-electric restaurant is 140 KVA which is supplied by a 120/208 V three phase supply. What is the required service conductor ampacity?

• 311 amperes
• 538 amperes
• 423 amperes
• 621 amperes

NEC Reference: NEC 220.88

Question 3: What size branch circuit protection is required for 20 A motor compressor connected to 240 volts single phase supply?

• 35 amperes
• 20 amperes
• 25 amperes
• 30 amperes

NEC Reference: NEC 440.22(A)

Question 4: A 30 ampere branch circuit with heavy duty lamp holders is permitted to supply fixed lightening units in .......................

• single family dwelling unit
• multi family dwelling unit
• any occupancy
• any occupancy other than dwelling unit

NEC Reference: NEC 210.23(B)

Question 5: What is the minimum general lightening load required for 1500 square foot single family dwelling unit as permitted by NEC?

• 4500 VA
• 4800 VA
• 3000 VA
• 1500 VA

NEC Reference: NEC 220.12

Question 6: What size service conductor is required for a 120/240 volts single phase with a demand load of 48 KVA?

• 200 amperes
• 150 amperes
• 100 amperes
• 250 amperes

Question 7: In calculating the load for a commercial kitchen with one electric appliance, which of the following demand factor is allowed?

• 100%
• 80%
• 90%
• 75%

NEC Reference: NEC 220.56

Question 8: The  ampacity of 2/0 THHN conductor is 195 amperes ( 90⁰ C). What is the maximum allowable ampacity of 2/0 THHN conductor in a conduit with 5 other current carrying conductors?

• 156 amperes
• 136 amperes
• 195 amperes
• 185 amperes

NEC Reference: NEC 310.15(B)(3)

Question 9: An isolated ground receptacle shall be identified by :................

• An orange triangle
• A permanent seal
• A green dot
• A cross sign

NEC Reference: NEC 406.3(D)

Question 10: If a panel board contains a snap switch with rating of 30 amperes must be protected not in excess of :

• 200 amperes
• 30 amperes
• 150 amperes
• 300 amperes

NEC Reference: NEC 408.36(A)

Question 11: 125 volt, 15 and 20 ampere receptacles installed in an unfinished basement of a dwelling unit require:

• GFCI protection
• AFCI protection only
• No protection is required
• A dedicated 50 ampere circuit

NEC Reference: NEC 210.8(A)(5)

Question 12: Flexible cords and fixture wires must be protected against overcurrent in accordance with their ampacity, as given in:

• NEC 400.5 and 402.5
• NEC 310.16 only
• No ampacity applies to cords
• The manufacturer's warranty card

NEC Reference: NEC 240.5

Question 13: Certain AC systems of 50 to 1000 volts are permitted, but not required, to be grounded, such as industrial systems supplying only:

• Industrial loads under engineering supervision, with ground detectors
• Every dwelling unit, without exception
• No system may ever be ungrounded
• Only outdoor lighting systems

NEC Reference: NEC 250.21

Question 14: A receptacle mounted directly to a surface-mounted metal box is permitted to be grounded through the mounting screws to the box, without a bonding jumper, when:

• The box is surface-mounted with direct metal contact
• This is never permitted, a jumper is always required
• The box is plastic
• The receptacle is a two-prong type

NEC Reference: NEC 250.146(A)

Question 15: Where a raceway is installed underground or in a concrete slab in direct contact with the earth, the interior of the raceway is considered a wet location. Conductors installed in it must be:

• Listed for use in wet locations
• Any standard dry-location conductor
• It does not matter
• Bare, uninsulated conductors

NEC Reference: NEC 300.9

Question 16: Per NEC Table 402.5, the allowable ampacity of an 18 AWG fixture wire is:

• 3 amperes
• 6 amperes
• 15 amperes
• 20 amperes

NEC Reference: NEC Table 402.5

Question 17: A general-use snap switch installed in a metal outlet box must be:

• Grounded via the mounting yoke or an equipment grounding conductor
• Insulated from the box, always
• It does not need any grounding connection
• Left loose inside the box

NEC Reference: NEC 404.11

Question 18: Where a grounding means does not exist in the outlet box, NEC 406.4(D)(1) permits a non-grounding-type receptacle to be replaced with which type?

• Another non-grounding-type receptacle
• A three-prong grounding receptacle with no ground connected, unmarked
• This is never permitted under any circumstances
• A 240 volt receptacle only

NEC Reference: NEC 406.4(D)(1)

Question 19: No part of a cord-connected luminaire, hanging fixture, lighting track, pendant, or ceiling fan is permitted within a zone measured 3 feet horizontally and 8 feet vertically from the top of a bathtub rim or shower stall threshold, unless:

• It complies with the GFCI/clearance conditions of 410.10(D)
• There is no restriction near tubs or showers
• Only if painted white
• It is never permitted regardless of protection

NEC Reference: NEC 410.10(D)

Question 20: The output circuit of a low-voltage lighting system power supply is limited to a rated output not exceeding:

• 25 amperes
• 50 amperes
• 100 amperes
• There is no limit

NEC Reference: NEC 411.5

Question 21: Receptacle outlets must not be mounted in, or above, an electric baseboard heater if the heater manufacturer's installation instructions:

• Prohibit that location
• It is always permitted, regardless of instructions
• Manufacturer instructions are never relevant
• Only the color of the heater matters

NEC Reference: NEC 424.9

Question 22: For a torque motor, conductor sizing is based on the nameplate current rating, since a torque motor:

• Is designed to operate in a stalled or slow-rotation condition
• Never draws any current
• Is identical to a standard motor in every way
• Cannot be sized under the NEC at all

NEC Reference: NEC 430.6(A)(2)

Question 23: For a single-phase room air conditioner rated 250 volts or less, the disconnecting means requirement may be satisfied by:

• The attachment plug and receptacle
• No disconnect is ever provided for room A/C units
• Only a separate breaker at the main panel
• Cutting the power at the utility meter

NEC Reference: NEC 440.63

Question 24: Dry-type transformers rated 600 volts, nominal, or less, located in the open on walls, columns, or structures, are generally:

• Permitted without a vault, if readily accessible
• Always required to be in a fire-rated vault
• Prohibited from being mounted on walls
• Never permitted indoors

NEC Reference: NEC 450.13(A)

Question 25: Flexible cord used in a Class I hazardous location must be of a type approved for extra-hard usage, and additionally must include:

• An equipment grounding conductor
• No equipment grounding conductor at all
• A wooden handle
• A built-in night light

NEC Reference: NEC 501.140

Question 26: Branch-circuit wiring methods for a mobile home must comply with the applicable requirements of Chapters 1 through 4 of the NEC, along with the specific rules of Article 550, similar to:

• A conventional dwelling unit's wiring rules
• No wiring method requirements apply to mobile homes
• Only Article 550, with nothing else applying
• Marine wiring rules under Article 555

NEC Reference: NEC 550.15

Question 27: Fixed, mobile, or portable electric signs and outline lighting, along with their associated equipment, must be:

• Listed
• Homemade with no listing
• Exempt from all NEC requirements
• Approved by the sign owner only

NEC Reference: NEC 600.3

Question 28: Acceptable sources for legally required standby systems include storage batteries, generator sets, uninterruptible power supplies, and:

• A separate service connection or fuel cell system
• A garden hose
• No other source is ever acceptable
• A telephone line

NEC Reference: NEC 701.12

Question 29: Energized parts of service equipment must be enclosed so that they are:

• Guarded against accidental contact
• Left fully exposed for easy access
• It does not matter
• Covered with tape only

NEC Reference: NEC 230.62

Question 30: Tap conductors meeting the specific length, ampacity, and protection requirements of NEC 240.21 are exempt from having overcurrent protection sized strictly at the point of supply because:

• Each tap rule provides an equivalent level of protection
• Tap conductors need no protection ever
• The tap rules do not exist in the NEC
• Tap conductors are always oversized regardless of load

NEC Reference: NEC 240.21