2020 NEC

30%

45%

60%

75%

A1) D

Q2) Generally, electrical metallic tubing shall be securely fastened in place within how many feet of each outlet or junction box?

1 ft

3 ft

4-1/2 ft

6 ft

A2) B

Q3) Overhead communications conductors are required to be maintained at least _______ above the maximum water level of a swimming pool?

10 ft

12 ft

15 ft

16 ft

A3) A

Q4) Which of the following dwelling unit areas does not require arc-fault circuit-interrupter (AFCI) protection for outlets supplied by 120V branch circuits?

Kitchen

Family room

Laundry area

Garage

A4) D

Q5) Which of the following applications is a permitted use for Type NM nonmetallic-sheathed cable?

Where embedded in attic insulation of a one- or two-family dwelling

In a location subject to excessive moisture or dampness

As service-entrance cable

Where embedded in poured concrete

A5) A

Q6) The point of attachment of overhead service conductors above finished grade to a building or other structure shall be not less than?

10 ft

12 ft

15 ft

18 ft

A6) A

Q7) Where calculating a residential load by the standard method, what minimum volt-ampere load is required to be used for the electric clothes dryer where its size is not known?

1500

3000

4500

5000

A7) D

Q8) A small appliance branch circuit in a dwelling unit shall comply with which one of the following?

Have no lighting outlets supplied by it

B limited to four outlets and four lights

Be protected with a 15-ampere overcurrent device

Be permitted in the living room

A8) A

Q9) A dwelling service is upgraded and an additional panelboard is added adjacent to the original one such that it would be necessary to pass conductors from one panelboard enclosure through the other panelboard enclosure. Which one of the following statements regarding conductors that pass through a cabinet that contains overcurrent devices is true?

Conductors are never permitted to feed through one panelboard to supply another panelboard.

They may fill up to 75% of the cross-sectional area of the gutter space.

They may fill up to 40% of the cross-sectional area of the gutter space.

A warning label identifying the location of the closest disconnecting means for the conductors feeding through is not required.

A9) C

Q10) In a dwelling unit, a 120/240-volt multiwire branch circuit supplying a split-wired kitchen duplex receptacle with the tab broken off between the ungrounded conductor terminals is permitted if the circuit is supplied by which one of the following?

Two single-pole circuit breakers with approved handle ties

Two single-pole circuit breakers with no handle ties

One single-pole circuit breaker

Two plug fuses

A10) A

Q11) The minimum wire bending space required for deflection of one 750-kcmil cable from the end of the lugs to the wall of the cabinet where the conductors enter or leave the cabinet opposite the terminal is:

8 in.

12 in.

14 in.

17 in.

A11) D

Q12) The sizing of conductors supplying several motors is based on which one of the following?

Full-load current of all motors in the group

Full-load current of all motors plus 25% of highest rated motor in the group

125% of the full-load current of all motors in the group

100% of the largest overcurrent device protecting the motors

A12) B

Q13) Where ground-fault protection of equipment (GFPE) is required for a solidly grounded wye system the maximum settling of the ground fault protection of equipment (GFPE( device shall be how may amperes?

300

1000

1200

1600

A13) C

Q14) The full-load amps of a 500 kVA transformer operating at 480Y/27-volts 3-phase is:

500 amperes

60 amperes

601 amperes

1042 amperes

A14) C

Q15) Conduit or raceways, including their end fittings, shall not rise above the bottom of a switchboard enclosure more than what distance?

3 in.

8 in.

10 in.

12 in.

A15) A

Q16) An outside 480Y/277-volt overhead feeder (open conductors) extends over a commercial area accessible to pedestrians but is not subject to truck traffic. What is the minimum clearance above grade?

8 ft

10 ft

12 ft

15 ft

A16) C

Q17) What is the general lighting load of an office building with an area of square feet and the actual number of general-purpose receptacle outlets is unknown?

13,500 VA

15,750 VA

18,000 VA

10,350 VA

A17) D

Q18) A generator set has been determined to be vital to the operation of an electrical system. Instead of interrupting the generator circuit, the overload sensing device may:

Be omitted

Be interlocked

Be connected to an annunciator

Interrupt the generator field circuit

A18) C

Q19) In an existing factory, a 277/480-volt switchboard faces a 120/240-volt panelboard on an opposite wall. If the switchboard is being replaced, and there are qualified persons servicing the installation, and written procedures prevent opening of both enclosures at the same time, what is the minimum working space between the new switchboard and the panelboard?

30 in.

36 in.

3-1/2 ft

14 ft

A19) C

Q20) Which one of the following taps is NOT permitted to be connected to the supply side of the service disconnecting means?

For load management devices

For a standby power system

To supply outside area lighting

To supply fire pump equipment

A20) C

Q21) The total inside area of a school is 160,000 s.f., and an outdoor-lighted play area is 120,000 s.f. The total connected load (including the air-conditioning), before applying demand factors is 1,740,000 VA. What is the total VA load for the school, after applying demand factors, as permitted using the optional method of calculation?

1,740,000 VA

1,425,000 VA

480,000 VA

1,305,000 VA

A21) B

Q22) Metal cabinets and boxes protected from corrosion solely by enamel are permitted to be used in which one of the following locations?

In outdoor locations

In car washes

In dairies

In enclosed parking garages

A22) D

Q23) What maximum percentage shall be used for overload protection to protect motors of one horsepower, marked not over 40 degrees C temperature rise and that start automatically?

100

115

125

140

A23) C

Q24) In paralleling conductors of size 1/0 AWG or larger, which one of the following conditions is NOT true?

They shall be of the same length and circular mil area.

They shall be of the same conductor material and insulation.

They shall be of the sunlight resistant type.

They shall be terminated in the same manner.

A24) C

Q25) A bare copper grounded (neutral) service-entrance conductor is permitted only if the voltage is not over which one of the following?

150 volts to ground

300 volts to ground

600 volts to ground

Any voltage in A, B, or C

A25) D

Q26) A 480Y/277-volt service is grounded at the utility transformer and enters a building. Under which one of the following conditions is it necessary to bring the grounded conductor into the service equipment?

Where only one 480-volt motor is installed

Where 3-phase motors and 277-volt lighting is installed

Where only 480-volt, 3-phase power is needed

All of the above

A26) D

Q27) What is the minimum volume required for a junction box containing six 12 AWG and three 10 AWG?

10.50 cu. in

12.50 cu. in

21 cu. in

14.50 cu. in

A27) C

Q28) 8 AWG Type THHN copper conductors are permitted to be installed in which one of the following locations?

Dry locations only

Dry and damp locations

Wet locations

Dry and wet locations

A28) B

Q29) What is the minimum working space in front of a panelboard where the voltage to ground is 120 volts?

36 in. wide and 36 in. directly in front

30 in. wide and 36 in. directly in front

30 in. wide and 33 in. directly in front

24 in. wide and 24 in. directly in front

A29) B

Q30) What is the minimum size THW copper conductor required to supply a load consisting of a 5-horsepower motor and a 1000-watt resistive appliance on one branch circuit? The circuit operates at 240 volts single-phase?

10 AWG

8 AWG

6 AWG

1 AWG

A30) B

Q31) Which one of the following statements about a cabinet is true?

It differs from a cutout box in that the cover is removable.

It is intended to be used with switchboards.

It cannot be installed in a dwelling unit.

It cannot be installed in wet locations.

A31) A

Q32) How many 300-watt industrial process lamps may be installed on a branch circuit rated at 15 amperes, 120 volts?

3

4

5

6

A32) B

Q33) What is the minimum size Type THW copper conductor required to serve an ac transformer arc welder with a 60 percent duty cycle and at 43 amperes primary current? Note: The termination points (lugs) at the welder are rated at 60 degree C.?

10 AWG

8 AWG

6 AWG

4 AWG

A33) B

Q34) Where motor branch-circuit short-circuit and ground-fault protection is provided by time-delay (dual-element) fuses and the rating is not sufficient to start the motor, it shall be permitted to increase the rating to what percentage of the full-load current rating of the motor?

150%

175%

225%

400%

A34) C

Q35) Which one of the following continuous rigid metal conduit raceway installations between pull points is in compliance?

A raceway with three 90-degree and two 45-degree bends

A raceway with three 90-degree and three 45-degree bends

A raceway with three 90-degree and four 30-degree bends

A raceway with two 90-degree, two 45-degree, and four 30-degree bends

A35) A

Q36) The controller for a 25-horsepower motor shall have a horsepower-rating not less than what percentage of the horsepower-rating of the motor?

100

115

125

150

A36) A

Q37) A panelboard contains 120/240-volt, multiwire branch-circuits, protected with 30-ampere or less single-pole overcurrent devices. What is the maximum number of overcurrent devices permitted in any one cabinet or cutout box?

18

42

30

The maximum number of overcurrent devices for which the panelboard was designed.

A37) D

Q38) What is the minimum depth of an outlet box without enclosed devices or utilization equipment?

½ in.

15/16 in.

1-1/4 in.

1-1/2 in.

A38) A

Q39) What is the feeder neutral current for a multifamily dwelling supplied with a 120/240-volt, 3-wire service with a calculated load (including demand factors as per Table 220.42) of 111,450 VA, including a 40 kVA range load per Table 220.55?

385 amperes

432 amperes

485 amperes

500 amperes

A39) A

Q40) What is the minimum size copper equipment grounding conductor permitted to be used for a circuit having 4/0 AWG phase conductors and protected with 250-ampere fuses?

8 AWG

6 AWG

4 AWG

3 AWG

A40) C

Q41) If the disconnecting means for a 230-volt ac, 5-horsepower motor is a motor circuit switch, the motor circuit switch must be horsepower rated not less than what rating?

5 horsepower

7 horsepower

10 horsepower

15 horsepower

A41) A

Q42) What is the minimum thickness permitted for a sheet metal steel of an uncoated electrical panelboard cabinet?

0.053 in.

0.060 in.

0.063 in.

0.090 in.

A42) A

Q43) Conductors supplying the following group of 3-phase, 230-volt induction motors: one 3-horsepower, two 5-horsepower and one 7-1/2-horsepower, shall have a minimum ampacity of how many amperes?

62.0

65.3

67.5

77.5

A43) C

Q44) The ampacity of a 2-wire, 18 AWG Type SO flexible cord is:

7 amperes

10 amperes

15 amperes

20 amperes

A44) B

Q45) What is the minimum headroom required for the working space in front of an 800-ampere service-disconnect switch?

6 ft

6 ft 3 in

6 ft 6 in

8 ft

A45) C

Q46) The minimum number of overload units providing overload protection for a 3-phase ac motor connected to a 208Y/120-volt, 3-phase, 4-wire system is:

1

2

3

4

A46) C

Q47) For branch-circuit or feeder calculations in industrial occupancies, what is the unit load for each outlet supplying heavy-duty lampholders that are not used for general illumination?

180 volt-amperes

600 volt-amperes

20 amperes

5 amperes

A47) B

Q48) What is the minimum size of Type THW copper conductors required to supply a load consisting of a 5-horsepower motor and a 1000-watt resistive appliance on one branch circuit? The circuit operates at 240 volts, single-phase.

10 AWG

8 AWG

6 AWG

1 AWG

A48) B

Q49) Receptacle outlets are required in all of the following locations at a one-family dwelling EXCEPT:

Basements

Underfloor space used for storage

Hallway that is 10 ft or longer

Outdoors at front and back at grade level

A49) B

Q50) In general, conductors between generator terminals and the first overcurrent device shall have an ampacity of at least what percentage of the nameplate current rating of the generator?

90 percent

100 percent

115 percent

125 percent

A50) C

Q51) Branch-circuit conductors supplying a single motor in a continuous duty application shall have a current-carrying capacity of not less than what percentage of full-load current of motor?

115 percent

125 percent

175 percent

250 percent

A51) B

Q52) A Class I location shall include locations containing all of the following atmospheres EXCEPT:

Hydrogen

Ethylene

Propane

Oxygen

A52) D

Q53) In computing general lighting loads by occupancies, how many watts (volt-amperes) per square foot is required for an office building that is not designed to meet any specific energy code when the actual number of general-purpose receptacle outlets is unknown?

2

3

3.5

2.3

A53) D

Q54) Single conductors installed in a ladder-type cable tray in an industrial establishment, under conditions of qualified maintenance and supervision, shall be a minimum size of:

1/0 AWG

2/0 AWG

4/0 AWG

250 kcmil

A54) A

Q55) Motor controllers and control circuit device terminals are to be connected with which one of the following conductors?

Copper only

Aluminum only

Either copper or aluminum

Copper only unless marked suitable for aluminum

A55) D

Q56) Which of the following is the NEC recommended maximum voltage drop on a feeder and branch circuit to the farthest outlet?

1.5 percent

2 percent

3 percent

5 percent

A56) D

Q57) What is the maximum locked rotor current amperes of a 40-horsepower 3-phase Code G 460-volt motor?

166 amperes

480 amperes

316 amperes

326 amperes

A57) C

Q58) All of the following statements about a motor disconnecting means and controller are true, except:

A control circuit push-button station located within sight from the controller may not be used as the motor disconnecting means.

The disconnecting means shall be located in sight from the controller

The locking provision for the disconnecting means is not required to remain in place.

The disconnecting means shall plainly indicate whether it is in the off or on position.

A58) C

Q59) The minimum ampacity of the phase conductors from the terminals of a 100-ampere-rated generator, which is not designed to prevent overloading to the first overcurrent device, shall not be less than how many amperes?

100 amperes

115 amperes

125 amperes

150 amperes

A59) B

Q60) Steel intermediate metal conduit may be installed under all of the following conditions EXCEPT:

Embedded in concrete

In direct contact with the earth

With aluminum fittings

Embedded in cinder fill underground without further protection