Massachusetts 2020 NEC Practice Exam

Welcome to your Massachusetts 2020 NEC Exam Quiz

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1. 
Except for __________ all 120-volt, single phase, 15-and 20-ampere branch circuits supplying outlets installed in dwelling units shall be protected by a listed arc-fault circuit interrupter, combination type installed to provide protection of the branch circuit.

2. 
Where a cable or raceway type wiring method is installed through bored holes in joist, rafters, or wood members, in both concealed and exposed locations, holes must be bored so that the edge of the hole is __________ in. or more from the nearest edge of the wood member. Where the distance is not possible, the cable or raceway must be protected from penetration by nails or screws by use of a steel bushing or plate, __________ in thick or more, and of the correct length and width installed to cover the area where the wiring is located.

3. 
A device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a ground-fault current exceeds the values established for a Class A device.

4. 
All switches and circuit breakers used as switches shall be located so the operating handle, when in its highest position, is not more than __________ above the floor or working platform.

5. 
For conductors on a branch circuit that supplies luminaires in a residence, what is the maximum allowable voltage between conductors on a branch circuit supplying luminaires in a residence?

6. 
All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same ___________.

7. 
An organization, office, or individual responsible for enforcing the requirements of a code or standard, or for approving equipment, materials, an installation, or a procedure.

8. 
Snap switches must not be ganged or grouped in enclosures with other receptacles, snap switches, or similar devices, unless they are placed so that voltage is __________ volts or less between adjacent devices, or unless placed in enclosures with securely installed, identified barriers between adjacent devices.

9. 
If a single receptacle is installed on an individual branch circuit, it must have an ampere rating of not less than __________ of the branch circuit.

10. 
What is the minimum burial depth in inches, in a trench below 2 inch thick concrete or equivalent for residential branch circuits rated at up to 120 volts with GFCI protection and overcurrent protection of 20 amperes or less?

11. 
Unless listed for controlling other loads and installed accordingly, general-use dimmer switches may be used only for permanently installed __________.

12. 
What do you call the midpoint on a single-phase, 3-wire system, or the common point on a wye-connection in a polyphase system, or a midpoint of a 3-wire, direct-current system, or midpoint of a single-phase portion of a 3-phase delta system?

13. 
Conductors for branch circuits that supply more than one receptacle for __________ loads must have an ampacity of at least the rating of the branch circuit.

14. 
Of the following, which must be provided for a conductor of a size 4 AWG or larger entering a panelboard?

15. 
A luminaire (fixture) that weighs more than __________ pounds or exceeds 16 inches in any dimension shall not be supported by the screw shell of a lampholder.

16. 
Panelboards shall be required to have overcurrent protection, except for __________.

17. 
Wherever flexible cords with attachment plugs are to be used, a receptacle outlet must be installed, and where such cords may be permanently connected, then receptacles are __________ for the same type of cords.

18. 
When electrical installations are in hollow spaces, ventilation or air-handling ducts and vertical shafts, they must be made so the chance of spread of fire or other products of combustion will not be substantially increased. Openings around electrical penetrations through or into fire-resistant-rated ceilings, floors, partitions, or walls must be __________ with approved methods to maintain the existing fire-resistance rating.

19. 
What is the maximum of the ampere rating of the switch for general use snap switches supplying inductive loads, at the applied voltage?

20. 
What table is used for current values to determine the required ampacity of the branch circuit conductors to supply a 3-phase, continuous duty ac motor?

21. 
Only __________ outlet loads may be supplied by branch circuits of over 50 amperes.

22. 
When wiring is located inside the cavity of a fire-rated floor-ceiling or roof-ceiling assembly, it may not be supported by or secured to ___________.

23. 
Outlets that supply boat hoists installed in dwelling unit locations and supplied by __________ shall have ground-fault circuit-interrupter protection for personnel.

24. 
Emergency systems are intended to automatically supply power and/or illumination that is essential for __________ and are legally required and classed as emergency by any governmental agency having jurisdiction.

25. 
Lighting systems for fountains, pools, spas, and similar locations must be installed __________ or more horizontally from the nearest water’s edge, unless Article 680 permits otherwise.

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