NEC 2020 Code Questions Practice Test 2

Question 1: The rated ampacity of a 1/0 THWN in a wet location is 150 amperes. If the same conductor is operated at ambient temperature of 40⁰C. What is its corrected ampacity?

• 132 amperes
• 150 amperes
• 142 amperes
• 138 amperes

Question 2: When eight three wire type AC cables are bundled in a raceway of length more than 24 inch. what is the adjustment factor that must be applied?

• 60 %
• 70 %
• 80 %
• 90 %

Question 3: The flexible cords employed for pool associated motors shall not exceed ………….. feet in length.

• 3
• 5
• 8
• 12

NEC Reference: NEC 680.21

Question 4: Whether by receptacle or direct connection the outlets supplying pool pump motors shall be provided with …………………………………… protection

• Over Current
• GFCI
• Over voltage

NEC Reference: NEC 680.21(C)

Question 5: When a conduit run passing from a Class I , Division 2 location into a unclassified location must have seal located with …………….. feet of the boundary.

• 10
• 15
• 20
• 8

NEC Reference: NEC 501.15

Question 6: If a panel board is supplied by a transformer. The over current device must be located ............. side of the transformer

• Primary Side
• Secondary Side

Question 7: Which of the following is the maximum rating of a branch circuit that supply the primary of low voltage lighting system power supply?

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

NEC Reference: NEC 411.6

Question 8: A lighting unit is connected on a 20 ampere branch circuit on which a fastened-in place appliance is located. What is the maximum percentage branch circuit rating is permitted on the appliance?

• 50 %
• 75 %
• 60 %
• 40 %

NEC Reference: NEC 210.23(A)(2)

Question 9: Which of the following is the smallest size wire permitted for a feeder circuit?

• No 10 AWG
• No 12 AWG
• No 14 AWG
• No 8 AWG

Question 10: When two or more single phase electric ranges are supplied by a 3 phase , 4 wire feeder, the total load computed is on the basis of ………………………….

• Twice the maximum number connected between any two phases
• Four times the maximum number connected between any two phases
• Three times the maximum number connected to a single phase

NEC Reference: NEC 250.55

Question 11: Per NEC Article 100, "readily accessible" means capable of being reached quickly for operation, renewal, or inspection, without requiring which of the following?

• Portable ladders, tools, or climbing over obstacles
• A written permit
• Special safety glasses
• A licensed electrician present

NEC Reference: NEC Article 100

Question 12: For a grounded AC service, the system bonding jumper connecting the grounded conductor to the equipment grounding conductor is normally installed at which location?

• At the service equipment
• At every downstream panelboard
• At the utility transformer only
• At the farthest branch circuit outlet

NEC Reference: NEC 250.24

Question 13: A detached garage is fed from the main dwelling by a feeder with an equipment grounding conductor. Is a grounding electrode also required at the detached garage?

• Yes, a grounding electrode is generally still required
• No, the equipment grounding conductor eliminates the need
• Only if the garage is over 1000 square feet
• Only if the garage has no metal parts

NEC Reference: NEC 250.32

Question 14: The service disconnecting means must be installed at a location that is:

• Readily accessible
• In a locked mechanical room only
• On the roof only
• Anywhere convenient for the installer

NEC Reference: NEC 230.70(A)(1)

Question 15: Which of the following is a standard ampere rating for fuses and inverse time circuit breakers listed in NEC 240.6(A)?

• 33 amperes
• 35 amperes
• 38 amperes
• 42 amperes

NEC Reference: NEC 240.6(A)

Question 16: A cable is installed through wood framing members, with the edge of the bored hole less than 1 1/4 inch from the framing edge. What protection is required?

• No protection is required
• A 1/16 inch steel plate or bushing
• A layer of electrical tape
• A larger diameter hole only

NEC Reference: NEC 300.4(A)(1)

Question 17: For a straight pull, a pull box or junction box must have a minimum length of not less than how many times the trade diameter of the largest raceway?

• 4 times
• 6 times
• 8 times
• 10 times

NEC Reference: NEC 314.28(A)(1)

Question 18: Electrical metallic tubing (EMT) must be securely fastened within 3 feet of each outlet box, and supported at intervals not exceeding:

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

NEC Reference: NEC 358.30

Question 19: Flexible cords and cables are prohibited from being run through which of the following, unless specifically permitted?

• Holes in walls, ceilings, or floors
• A open coil on the floor near the equipment
• A properly rated portable tool
• A temporary holiday display

NEC Reference: NEC 400.8

Question 20: A metal faceplate installed on a switch or receptacle must be:

• Grounded
• Insulated from ground
• Painted
• Left ungrounded for safety

NEC Reference: NEC 404.9(B)

Question 21: A surface-mounted incandescent luminaire with a completely enclosed lamp, installed in a clothes closet, must maintain a minimum clearance from the nearest point of storage space of:

• 6 inches
• 12 inches
• 18 inches
• 24 inches

NEC Reference: NEC 410.16

Question 22: A wall-mounted range hood is permitted to be cord-and-plug connected provided the flexible cord length is within what range?

• 6 to 12 inches
• 18 to 36 inches
• 48 to 60 inches
• Any length is permitted

NEC Reference: NEC 422.16(B)(4)

Question 23: Conductors supplying two or more motors must have an ampacity of not less than 125% of the full-load current of the highest-rated motor, plus:

• The sum of full-load currents of all other motors
• Nothing additional is required
• 10% of the branch circuit rating
• The voltage rating of the smallest motor

NEC Reference: NEC 430.24

Question 24: The disconnecting means for air-conditioning or refrigeration equipment must be located:

• Within sight from and readily accessible from the equipment
• Inside the equipment enclosure only, hidden from view
• At the main service panel only
• Anywhere in the building

NEC Reference: NEC 440.14

Question 25: A generator, other than a cord-and-plug-connected portable generator, must be equipped with what safety feature?

• A disconnecting means for the generator windings
• A fireproof enclosure only
• A backup battery
• No safety feature is required

NEC Reference: NEC 445.18

Question 26: Temporary electrical wiring installed for the period of construction, remodeling, or similar activity is permitted for a maximum of:

• The period of construction or similar activity
• 1 year, regardless of the activity
• Temporary wiring may remain permanently
• 10 days maximum in all cases

NEC Reference: NEC 590.3

Question 27: For circuits rated 100 amperes or less, conductor ampacity must be selected and coordinated based on which temperature rating, unless the equipment is listed otherwise?

• 60 C
• 75 C
• 90 C
• 105 C

NEC Reference: NEC 110.14(C)(1)(a)

Question 28: A multi-wire branch circuit supplying more than one device or equipment on the same yoke must be provided with a means to:

• Simultaneously disconnect all ungrounded conductors
• Disconnect only the neutral conductor
• Nothing extra is required
• Disconnect one phase at a time only

NEC Reference: NEC 210.4(B)

Question 29: A rod-type grounding electrode must have a minimum length of:

• 4 feet
• 6 feet
• 8 feet
• 10 feet

NEC Reference: NEC 250.52(A)(5)

Question 30: Where two rod electrodes are used and one does not meet the 25 ohm resistance requirement, they must be separated by at least:

• 2 feet
• 6 feet
• 10 feet
• 15 feet

NEC Reference: NEC 250.53(A)(3)