325 Practice Questions for Electricians

Disregarding exceptions, FMC shall be securely fastened in place by an approved means within __________ of each box, cabinet, conduit body, or other conduit termination and shall be supported and secured at intervals not to exceed ___________. Where used, cable ties shall be listed and be identified for securement and support.

Electric currents cause __________, which creates light in incandescent light bulbs. They also create magnetic fields, which are used in motors, inductors, and generators.

At all points where the armor of __________ terminates, a fitting shall be provided to protect wires from abrasion, unless the design of the outlet boxes or fittings is such as to afford equal protection, and in addition, an insulating bushing or its equivalent protection shall be provided between the conductors and the armor?

The minimum size service conductors (AL) for a 150 Amp service in a single-family dwelling unit is __________.

Where Compressed Natural Gas or Liquefied Natural Gas dispensers are installed beneath a canopy or enclosure, either the canopy or enclosure shall be designed to prevent accumulation or entrapment of ignitable vapors or all electrical equipment installed beneath the canopy or enclosure shall be suitable for __________.

The use of strut-type channel raceways shall not be permitted in which of the following:

In a(n) __________ system, electrical equipment, wiring, and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit from any point on the wiring system to the electrical supply source to facilitate the operation of overcurrent devices should a second ground fault from a different phase occur on the wiring system.

An enclosure designed for surface mounting that has swinging doors or covers secured directly to and telescoping with the walls of the enclosure is:

FMC shall not be used in the following:

For a storage warehouse, what portion of the lighting load does a 50% demand factor apply to?

The conductor between the surge arrester and the line and the surge arrester and the grounding connection, on a 2,000-volt service, shall not be smaller than __________.

A pool has a diving platform that extends 4 feet above the surface of the water.  There is a set of 3 overhead conductors supported on a Solidly Grounded Messenger wire that run over the pool, and over the diving platform.  What is the minimum clearance these conductors must be from the diving platform?

If the output of a 10hp 120-volt DC motor is 7,460 Watts and the input is 9,120 Watts, what is the efficiency of the motor?

Type MV cable terminated in equipment or installed in pull boxes or vaults shall be secured and supported by metallic or nonmetallic supports suitable to withstand the weight by cable ties listed and identified for securement and support, or other approved means, at intervals not exceeding __________ from terminations or a maximum of __________ between supports.

In straight pulls, the length of the box or conduit body shall not be less than __________ the metric designator (trade size) of the largest raceway.

The voltage of an AC circuit can be increased or decreased but the frequency cannot be changed.

A single-family dwelling out in the country has a floor area of 1500 square feet, with no garage. Appliances are a 10-kW range and a 6-kW, 240-volt dryer. There are no heating or air conditioning loads, nor a dishwasher or garbage disposal. Using the Standard Method, calculate the minimum size feeder required for this dwelling.

The minimum size service conductors for a 200 Amp service in a single-family dwelling unit is__________.

In a Commercial Garage, all 125-volt, single-phase, 15- and 20-ampere receptacles installed in areas where electrical diagnostic equipment, electrical hand tools, or portable lighting equipment are to be used shall have __________.

All 15- and 20- ampere, 125- and 250-volt nonlocking-type receptacle shall be listed tamper-resistant receptacles, except in which of the following instances:

The earth shall be considered as an effective fault-current path.

A grounded circuit conductor shall not be used for grounding non-current-carrying metal parts of equipment on the load side of the service disconnecting means or on the load side of a separately derived system disconnecting means or the overcurrent devices for a separately derived system not having a main disconnecting means, except for which of the following:

Ceiling outlets shall be required to support a luminaire weighing a minimum of __________.  A luminaire that weighs more than __________shall be supported independently of the outlet box, unless the outlet box is listed for not less than the weight to be supported.

At a Highschool, the general lighting load shall be calculated at __________ VA per square foot. 

The largest number of 4 AWG THW conductors that can be installed an 18-inch piece of 1 1/4″ Liquidtight Flexible Nonmetallic Conduit shall be:

Lamps located in cellulose nitrate film vaults shall be installed in rigid luminaires of the __________ type.

Calculate the total service size for the following residence, using the STANDARD METHOD:

• 1500 square foot home
• trash compactor 1100VA
• range 6000VA
• dryer 4000VA
• 2 ovens (3kVA each)
• disposal 940VA
• water heater 4500VA
• dishwasher 1250VA
• AC 6440VA
• Heat 9000VA
• Lighting = 4500VA
• Laundry = 1500VA
• Small Appliance = 3000VA

Equipotential planes of agricultural buildings shall be connected to the electrical grounding system. The bonding conductor shall be solid copper, insulated, covered or bare, and not smaller than __________. The means of bonding to wire mesh or conductive elements shall be by pressure connectors or clamps of brass, copper, copper alloy, or an equally substantial approved means. Slatted floors that are supported by structures that are a part of an equipotential plane shall not require bonding.

Conductors that are capable of being removed or exposed without damaging the building structure or finish or not permanently closed in by the structure or finish of the building is said to be ____________.

The electrons in the outer shell of an atom are called __________.

In a 1-phase 240/120-volt service feeding a Single-Family Dwelling rated 100- through 400- amperes, the service conductors supplying the entire load associated with a one-family dwelling, or the service conductors supplying the entire load associated with an individual dwelling unit in a two-family or multifamily dwelling, shall be permitted to have an ampacity not less than __________.

The fixed appliance load for a single-family dwelling with the following 120V fixed in place appliances is __________:

• Water Heater- 8000 VA
• Dishwasher- 1600 VA
• Garbage Disposal- 1000VA

For motors used in alternating-current, adjustable voltage, variable torque drive systems, the ampacity of conductors, or ampere ratings of switches, branch-circuit short-circuit and ground-fault protection, and so forth, shall be based on ___________.

Luminaires shall be constructed, installed, or equipped with shades or guards so that combustible material is not subjected to temperatures in excess of __________.

All pull boxes, junction boxes, and conduit bodies shall be provided with covers compatible with the box or conduit body construction and suitable for the conditions of use. Where used, metal covers shall:

Luminaires shall be constructed, installed, or equipped with shades or guards so that combustible material is not subjected to temperatures in excess of:

A 100x54mm (4×2 1/8”) metal square box, having a minimum volume of 30.3 cubic inches, shall be allowed to have no more than __________ 12 AWG conductors in it.

What is the monthly cost of operating a 240-volt, 5-kW central electric heater that operates 12 hours per day when the cost is 15 cents per kWhr (kilowatt-hour)?

Disregarding exceptions, any portion of electrical wiring that is below the surface of a Class I, Division 1 or a Class I, Division 2 location shall be sealed within __________ of the point of emergence above grade.

Determine the demand load of the service-entrance conductors for a restaurant kitchen that contains the following cooking equipment (after applying permitted demand factors):

• (1) 14 kW range
• (1) 5 kW water heater
• (1) 750 W mixer
• (1) 2500 W dishwasher
• (1) 2 kW booster heater
• (1) 2 kW broiler

What is the feeder/service neutral calculated load for the following service:

• 200 amp Line to Line loads
• 200 amp Line to Neutral Nonlinear Loads
• 200 amp Line to Neutral Linear Loads

In a multi-family dwelling which of these 120-volt, single-phase, 15- and 20-ampere branch circuits shall be protected with an arc-fault circuit-interrupter?

The distance outward that an expanding and collapsing electromagnetic field around a conductor can reach, is __________.

The service conductors between the terminals of the service equipment and a point usually outside the building, clear of building walls, where joined by tap or splice to the service drop or overhead service conductors – is defined as what?

The fixed appliance load for a single-family dwelling unit with a 950 VA Garbage Disposal, a 1200 VA Dishwasher and a Water Heater rated at 7500VA, all rated at 120V is __________.

In an Ungrounded 240-volt 3-phase system, an equipment grounding conductor shall be installed with the supply conductors and be connected to the building or structure disconnecting means and to the grounding electrode(s).  The grounding electrode(s) shall also be connected to __________.

Luminaires shall be constructed, installed or equipped with shades or guards so that combustible material is not subjected to temperatures in excess of ____________.

Receptacles shall be mounted in identified boxes or assemblies. The boxes or assemblies shall be securely fastened in place unless otherwise permitted elsewhere in this code. Screws for the purpose of attaching receptacles to a box shall be of the type provided with a listed receptacle, or shall be machine screws having __________ threads per inch:

The ampacity of UF cable shall be that of:

A branch-circuit overcurrent protective device is a device capable of providing protection for service, feeder, and branch circuits and equipment over the full range of over-currents between its __________ and its __________.

Electrical wiring for lighting, where installed inside of tents and concessions, shall be securely installed and, where subject to physical damage, shall be provided with __________.

In instances of areas within the same facility classified separately, Class I, Zone 2 locations shall be permitted to __________ Class I, Division 2 locations.

Two 75kVA 208/480V transformers are installed in parallel and protected by a common overcurrent protection device, on the primary side only. What size should this primary OCPD be to protect this transformer bank?

What is the minimum allowable ampacity of THWN copper conductors run to a three-phase continuous load that is rated 250-volts, 50-amperes which is located 50-feet from its overcurrent device?  The conductors are inside of a piece of 1-inch EMT, the ambient temperature of the environment is 84-degrees Fahrenheit, and there are 3 current-carrying conductors in the raceway.

The amount of EMF surrounding a conductor __________ with a(n) __________ in current flow through the conductor.

An incandescent lamp for general use on lighting branch circuits shall not be equipped with a medium base if rating over __________, or with a mogul base if rated over __________.

The demand load for a dryer in a single-family dwelling unit, rated at 6,000 VA is __________.

Where heating equipment is supplied by more than one source, feeder, or branch circuit, the disconnecting means shall be __________.  Each disconnecting means shall simultaneously disconnect all ungrounded conductors that it controls.

In a dwelling unit, the clearance for overhead service conductors, not in excess of 600 volts, measured at the driveway is __________ minimum from final grade.

A receptacle outlet shall be installed at each countertop and work surface that is __________ or wider.

The supply-side bonding jumper for a 240-volt single-phase service fed with (2) 300kcmil Aluminum ungrounded conductors should be what size:

Select the feeders for a series of ranges being installed in a structure, based on the following loads:

• 5 ranges, each rated at 11 kW
• 2 ranges, each rated 12 kW
• 20 ranges, each rated 13.5 kW
• 3 ranges, each rated 18 kW

A dead end of a busway shall be __________.

What is the minimum size grounded conductor is required for a feeder consisting of (3) 250 kcmil ungrounded conductors and (1) grounded conductor protected by a 250-ampere OCPD? [The unbalanced load is 50-amperes, with 75 deg Celcius terminals]

Fixed equipment that may produce arcs, sparks, or particles of hot metal, such as lamps and lampholders for fixed lighting, cutouts, switches, receptacles, motors, or other equipment having make-and-break or sliding contacts, shall be of the __________ or be constructed so as to prevent the escape of sparks or hot metal particles

Restricted access, as it pertains to a Restricted Access Adjustable-Trip Circuit Breaker, shall be defined as located behind one of the following:

The electric vehicle coupler shall be provided with a grounding pole, unless __________.

A half-wave and full-wave rectifier are both used to __________.

Copper conductors, for each phase, polarity, neutral, or grounded circuit shall be permitted to be connected in parallel (electrically joined at both ends) only in sizes __________ where installed in other than exempt control circuits.

The demand load for the grounded conductor (neutral) for a 6,000 VA dryer is__________.

A box containing pendant- or flush-mounted receptacles attached to a multiconductor cable via strain relief or a multipole connector is:

Excluding exceptions, what is the smallest size of underground service conductors that can be utilized:

When installing conductors in a rigid metal conduit that is buried under 3 inches of concrete, to what depth does this conduit need to be buried?

For a one-family dwelling with a service rated 400-amps, the service conductors supplying the entire load associated with a one-family dwelling, or the service conductors supplying the entire load associated with an individual dwelling unit in a two-family or multifamily dwelling, shall be permitted to have an ampacity not less than __________ of the service rating.

What is the total demand load for the following restaurant:

A restaurant has all electric appliances, a connected lighting load that includes a sign, totaling 50,000VA.  The electrical service is rated at 120/208-volt, three-phase.  The restaurant contains the following loads:

120-volt loads

• 60 duplex receptacles
• 100 ft multi-outlet assembly (simultaneous rated)
• 1 broiler 5 kW
• 2 deep fryers 5.5 kW
• 1 freezer 3,400VA
• 1 booster heater 1,500VA
• 1 coffee service machine 3,500VA
• 1 dishwasher 3,500VA

208-volt loads

• 1 walk-in cooler 6,400VA
• 1 water heater 4,800VA
• 1 oven 20kW
• 1 range 15kW
• 2 convection ovens 8kW
• 15kW electric heater
• 14kW AC
• 3 exhaust fans 2.4 amperes
• 1 cooktop 10kW
• 2 10kW heating units

The rating or setting of the overcurrent protective device for the circuit supplying the industrial control panel shall not be greater than the sum of the largest rating or setting of the branch-circuit short-circuit and ground-fault protective device provided with the industrial control panel, __________, plus the sum of the full-load currents of all other motors and apparatus that could be in operation at the same time.

What is the feeder/service calculated load for (2) 15kW water heaters, (1) 3kW oven, and (1) 2kW deep fryer in a commercial kitchen?

Up to __________ sets of 3-wire feeders or __________ sets of 4-wire or 5-wire feeders shall be permitted to utilize a common neutral.

All raceways, cable trays, cable bus framework, auxiliary gutters or service cable armor or sheath that enclosed, contain or support service conductors shall be __________.

Where used as service-entrance conductors, size 250 kcmil Type IGS cable has an allowable ampacity of __________.

Impedance includes the following:

Conductors that supply one or more welders shall be protected by an overcurrent device rated or set at not more than:

What is the line demand load for a dryer with a nameplate rating of 4,800 VA.

For a single-family dwelling, the service disconnecting means shall have a rating of not less than __________.

Raceways shall be used as a means of support for other raceways under which condition?

Multi-wire branch circuits shall supply only __________.

Threadless couplings and connectors used with conduit shall be made tight. Where buried in masonry or concrete, they shall be __________.

Which of these is considered the “highest-rated” motor:

Select the feeder conductor size for the following motor group, using 75 degree terminations, and THW copper conductors. (All have a S.F. of 1.15 and a Marked Temp Rise of 40 degrees C):

Motor Group consists of 4 motors tapped on the same feeder:

• Motor 1 – 3 phase, 208 V, 50 HP motor
• Motor 2 – 3 phase, 208 V, 30 HP motor
• Motor 3 – 3 phase, 208 V, 20 HP motor
• Motor 4 – 3 phase, 208 V, 10 HP motor

Determine the MINIMUM 20-ampere, 277-volt general lighting branch circuits required for a 150,000 square foot retail department store when the actual connected lighting load is 400 kVA. *Note: Circuit breakers of this size are not rated for continuous use.

A 60 cycle-per-second waveform changes direction __________ times per second.

Nonmetallic-sheathed cable shall be supported and secured by staples, or other means, at intervals not exceeding __________ and within __________ of every cable entry into enclosures such as outlet boxes, junction boxes, cabinets, or fittings.

The line demand load and neutral demand load for a dryer with a nameplate rating of 6,500 VA is:

Fire-Resistive Cable System cables and conductors shall be surface marked with the suffix __________, along with the circuit integrity duration in hours, and with the system identifier.

Excluding exceptions, what is the minimum size of Overhead Service Conductors?

Fixed electric space heating equipment and motors shall be considered what type of load?

Type NM, Type NMC, and Type NMS cables shall be permitted to be used in the following, except as prohibited in 334.12:

Fire alarm circuits shall be identified at terminal and junction locations in a manner that __________ during testing and servicing of other systems.

What is the cubic inch capacity required for a device box containing (1) duplex receptacle, (2) cable clamps, and (2) 12AWG with ground nonmetallic sheathed cables?

Where supplementary overcurrent protection is used for luminaires, appliances, and other equipment or for internal circuits and components of equipment, it __________ as a substitute for required branch-circuit overcurrent devices or in place of the required branch-circuit protection.

Where structural reinforcing steel is not available or encapsulated in a nonconductive compound, a copper conductor(s) shall be utilized where all of the following requirements are met, except:

The allowable ampacity of a size 4 AWG THW copper conductor installed in a conduit with three (3) other current-carrying conductors of the same size and insulation, in a location with an ambient temperature of 89 degrees F is __________.

Current will primarily flow __________.

Which 120-volt, single-phase, 15- and 20-ampere dwelling branch circuits, supplying outlets or devices, shall be protected by an AFCI device?

When connecting energy storage systems to other sources, only inverters and ac modules listed and identified as __________ shall be permitted on interactive systems.

For each dryer in a dwelling unit, __________ volt-amperes shall be used when calculating the load for the service.

In a dwelling unit, which of these locations are NOT required to be protected by and arc- fault circuit interrupter?

Equipment that utilizes electric energy for electronic, electromechanical, chemical, heating, lighting, or similar purposes is the definition of what?

Electrical continuity at service equipment, service raceways, and service conductor enclosures shall be ensured by one of the following methods:

Underground wiring shall be installed in threaded rigid metal conduit or threaded steel intermediate metal conduit or, where buried under not less than __________ of cover, shall be permitted in Type PVC conduit, Type RTRC conduit, or a listed cable.

What is the cost of power consumed per month, at $0.09/kWh, for a 120-volt circuit that’s faulted to a ground rod with 25-ohms of resistance?

A 3-phase 240-volt service fed with (3) 2/0 aluminum conductors shall have a minimum size main bonding jumper of what size?

Each branch-circuit disconnect rated __________ or more and installed on solidly grounded wye electrical systems of more than 150 volts to ground, but not exceeding 600 volts phase-to-phase, shall be provided with ground-fault protection of equipment

Where a 20-ampere rated branch-circuit in a residence supplies only fixed resistance-type baseboard electric heaters, this branch-circuit may be loaded to a MAXIMUM value of __________.

A building that consists solely of two dwelling units is a(n) __________.

Disregarding special conditions or occupancies, a building or other structure that is served by a branch circuit or feeder on the load side of a service disconnecting means shall be supplied by __________.

Determine the total Heating and A/C load for a single-family dwelling unit with the following (rated at 240 V):

• Heating- 16,000 VA
• A/C- 10,000 VA

In a dwelling unit, the overhead service conductors (not over 1000 volts) shall be kept not less than __________ feet from the side of a window that is designed to be opened.

No parts of cord-connected luminaires, chain, cable, or cord suspended luminaires, lighting track, pendants, or ceiling-suspended (paddle) fans shall be located within a zone measuring horizontally and __________ vertically from the top of the bathtub rim or shower stall threshold.

In a separately derived system, a supply-side bonding jumper shall not be required to be larger than:

Type 4 component assemblies and other component type SPDs shall: 

A bare #4 AWG copper conductor has a diameter of __________.

Overhead spans of open conductors and open multiconductor cables of not over 1000 volts, nominal, shall have a clearance of not less than __________ over public streets, alleys, roads, parking areas subject to truck traffic, driveways on other than residential property, and other land traversed by vehicles, such as cultivated, grazing, forest, and orchard

Determine the MINIMUM size listed metal box permitted by the NEC that contains . two (2) size 12 AWG. conductors and three (3) size 8 AWG conductors.

A dwelling unit is a single unit, providing complete and independent living facilities for one or more persons, including permanent provisions for:

The ground fault protection system shall operate to cause the service disconnect to open all ungrounded conductors of the faulted circuit.  The maximum setting of the ground-fault protection shall be __________ amperes, and the maximum time delay shall be one second for ground-fault currents equal to or greater than __________ amperes.

What is the additional motor load needed for a single-family dwelling unit with an attic fan rated at 1,500 VA, 120-V.

Snap switches are considered to be part of the effective ground-fault current path when __________.

The service disconnecting means shall consist of not more than __________ switches or circuit breakers.

The ampacity of the branch circuit conductors and the rating or setting of overcurrent protective devices shall not be less than __________ of the total nameplate rated load.

The width of working space in front of electrical equipment shall be the width of the equipment or __________, whichever is greater.

In an outside branch circuit, open conductors shall be separated from open conductors of other circuits or systems by not less than __________.

As a fixed wiring method encased in 3 inches of concrete, Type AC cable shall be permitted to be used where installed in an occupancy where more 100 or more people will gather or assemble.