NEC 2023 Code Questions Practice Test 1

Question 1: If a 115 volts load is connected to 120 v source. what is the minimum voltage that should be supplied to load as recommended by NEC?

• 114 volts
• 120 volts
• 115 volts
• 118 volts

Question 2: What is the receptacle calculated load for a 18000 square feet commercial property which contains one hundred twenty 15 A and 20 A 120 receptacles?

• 15800 VA
• 18000 VA
• 16800 VA
• 21500 VA

NEC Reference: NEC 220.14(1)

Question 3: In no case the rating of short  circuit ground fault protective device for a single motor compressor should not exceed ..... percentage of the motor.

• 175 %
• 225 %
• 220 %
• 150 %

NEC Reference: NEC 440.22(A)

Question 4: The service disconnect for a mobile home should be located not less than ............. feet above platform.

• 1
• 2
• 1/2
• 3

NEC Reference: NEC 550.32(F)

Question 5: What is the minimum feeder or service load for cloth dryers in a dwelling unit?

• 5000 watts
• 2800 watts
• 4500 watts
• 6500 watts

NEC Reference: NEC 220.54

Question 6: A 4000 watts electric oven is connected to a 480 volts circuit. What is the resistance of heating element?

• 57.6 ohms
• 78.6 ohms
• 82 ohms
• 48

Question 7: In a three phase balanced 4-wire system, the current in the neutral conductor ...............................

• is same as un-grounded conductors
• is higher than other conductors
• is lower than other conductors
• will not flow as the circuit is balanced

Question 8: Which of the following conductors need over current protection on a residential electric service?

• un-grounded conductor
• grounded conductor
• neutral conductor
• equipment grounding conductor

NEC Reference: NEC 240.15

Question 9: In class I Division 1 location, All fixed boxes and joints should be made ..............

• explosion proof
• water proof
• dust proof
• fire proof

NEC Reference: NEC 500.7(A)

Question 10: The feeder or service neutral load is generally computed based on the maximum net calculated load between the:

• Neutral conductor and any one ungrounded conductor
• Two ungrounded conductors only, ignoring the neutral
• The ground and the neutral
• It is always 100% of the total connected load

NEC Reference: NEC 220.61

Question 11: A means must be provided to disconnect all ungrounded conductors of each outside branch circuit or feeder at the point where they:

• Enter the building or structure
• Leave the utility pole
• No disconnect is ever required
• Cross a property line

NEC Reference: NEC 225.31

Question 12: Which of the following is permitted to be connected on the supply side of the service disconnecting means?

• A listed surge-protective device
• A general-purpose lighting panel
• A branch-circuit receptacle
• A motor branch circuit

NEC Reference: NEC 230.82

Question 13: Overcurrent devices must be enclosed in cabinets, cutout boxes, or equipment enclosures, unless they are:

• Part of controllers or assemblies designed for exposed mounting
• Never permitted to be enclosed
• Always mounted outdoors uncovered
• Wrapped in tape only

NEC Reference: NEC 240.30

Question 14: Grounding and bonding connections that are not required to be accessible must be made by which of the following methods, among others listed in the code?

• Exothermic welding or listed pressure connectors
• Solder alone
• Electrical tape alone
• No connection method is specified

NEC Reference: NEC 250.8

Question 15: NEC 250.118 lists acceptable types of equipment grounding conductors. Which of the following qualifies?

• Rigid metal conduit
• A garden hose
• A telephone line
• A wood support beam

NEC Reference: NEC 250.118

Question 16: Ferrous metal raceways, cable trays, boxes, and fittings that are to be installed in wet locations must be protected from corrosion by which method?

• A corrosion-resistant coating, such as galvanizing
• No protection is required
• Painting the outside only, with the inside left bare
• Wrapping in plastic bags

NEC Reference: NEC 300.6

Question 17: Conductor ampacity must be determined either by the tables in Article 310, or by:

• Engineering supervision using recognized ampacity calculations
• Guesswork, with no basis needed
• It cannot be determined any other way
• The homeowner's preference

NEC Reference: NEC 310.14

Question 18: Outlet, device, and other boxes must have a minimum depth sufficient to accommodate the equipment they enclose, but generally not less than:

• 1/2 inch
• 4 inches
• 1/8 inch
• There is no minimum

NEC Reference: NEC 314.24

Question 19: Type UF (underground feeder) cable is permitted for use:

• As direct-buried underground feeder or branch-circuit cable
• Only above ground indoors
• It has no permitted use
• Only for telephone wiring

NEC Reference: NEC 340.10

Question 20: Where flexibility is necessary after installation, flexible metal conduit (FMC) is permitted to be unsupported for a length not exceeding:

• 3 feet
• 6 feet
• 10 feet
• 12 feet

NEC Reference: NEC 348.30(A)

Question 21: Switches or circuit breakers used as switches must generally be installed so the center of the grip of the operating handle, at its highest position, is not more than:

• 6 feet 7 inches
• 4 feet
• 8 feet
• There is no height limit

NEC Reference: NEC 404.8(A)

Question 22: Where a receptacle is replaced on a branch circuit that requires AFCI protection, but the panel does not have an AFCI breaker, the replacement receptacle is permitted to be:

• A listed outlet-branch-circuit AFCI receptacle
• Any standard non-AFCI receptacle
• No AFCI protection is ever required for replacements
• A GFCI receptacle only, ignoring AFCI

NEC Reference: NEC 406.4(D)(4)

Question 23: A recessed luminaire that will be in direct contact with thermal insulation must be listed as Type:

• Type IC (insulation contact)
• Type NM
• Type AC
• No listing is required

NEC Reference: NEC 410.116(A)

Question 24: A cord-and-plug-connected waste (food) disposer under a sink is permitted to have a flexible cord length within what range?

• 18 to 36 inches
• 3 to 6 inches
• 5 to 8 feet
• Any length

NEC Reference: NEC 422.16(B)(1)

Question 25: Embedded heating cables for radiant floor heating must not be installed under permanently installed cabinets or where they would be:

• Beneath permanently installed cabinets
• Anywhere in an open floor area
• It may be installed anywhere with no restriction
• Only near a window

NEC Reference: NEC 424.44(E)

Question 26: A stationary motor rated 1 horsepower or less, normally left running continuously, is permitted to be protected against overload by:

• The branch-circuit, short-circuit, and ground-fault protective device
• No protection at all is permitted
• A separate 400% rated fuse only
• A padlock on the motor housing

NEC Reference: NEC 430.32(B)

Question 27: Article 440 (Air-Conditioning and Refrigerating Equipment) supplements or amends the general motor rules of Article 430 for equipment using a hermetic motor-compressor. Where Article 440 does not specifically address a topic, which article generally applies?

• Article 430 (Motors)
• Article 250 (Grounding)
• Article 90 only
• No other article ever applies

NEC Reference: NEC 440.3

Question 28: Guards, isolation by elevation, or an enclosure must be provided to protect employees from live current-carrying generator parts operating at more than:

• 50 volts
• 600 volts
• 12 volts
• No protection is ever required

NEC Reference: NEC 445.15

Question 29: Exposed non-current-carrying metal parts of a transformer installation, such as the core and case, must be:

• Grounded, per Article 250
• Left ungrounded intentionally
• Painted for identification only
• It does not matter

NEC Reference: NEC 450.10

Question 30: In a Class II, Division 1 location, combustible dust is present in the air under normal operating conditions in quantities sufficient to produce:

• Explosive or ignitible mixtures
• No hazard at all
• Only cosmetic dust buildup
• Static discharge with no fire risk

NEC Reference: NEC 500.5(C)(1)