Final quiz

Lakukan tugas rumah & ujian kamu dengan baik sekarang menggunakan Quizwiz!

The junction box and recessed lighting fixture should be separated by a minimum distance of _____.

1'

the junction box and recessed lighting fixtures should be separated by a minimum distance of

1'

Boxes must be marked with the words "DANGER — HIGH VOLTAGE — KEEP OUT" if they house conductors over _____.

1,000V

The synchronous speed at which a four-pole, 60Hz induction motor operates is _____.

1,800 rpm

the most common service factor appearing on a motor's name plate is

1.15

All switchboards, switchgear, panelboards, and motor control centers shall be located in dedicated spaces and protected from damage and and the working clearance space for outdoor installations shall include the zone described in ____.

110.26(A)

A polyphase synchronous motor has three stator windings that are _____.

120° apart

If a 20A branch circuit supplies multiple receptacles, the receptacles shall have an ampere rating of no less than ____.

15A

How much conduit is needed if the rise is 15", the leg length is 10", and the gain is 8.6"?

16.4"

A circuit has a peak voltage of 275V. What is the average voltage value?

175V

The minimum clearance for overhead service conductors not exceeding 600V that pass over commercial areas subject to truck traffic is ____ ft.

18

A three-phase induction motor may have _____.

2 poles

For a pull box housing shielded conductors carrying over 1,000V and used in an angled pull, the distance between a conductor entry and exit must be _____.

36 times greater than the OD of the conductor

You are making a 14" stub-up in 1" RMC and the bender deduct is listed as 10". Where do you make your first mark?

4" from the end of the conduit

Which of the following square junction boxes must be used if there is one 6" conduit and two 4" conduits entering on one side of the box and exiting at a 90° angle on another side of the box? (Assume the conductor size is No. 4 AWG or larger, but operating at less than 1,000V.)

44"

Hydraulic benders are capable of bending rigid pipe up to and including _____.

5" in diameter

Unless it is protected or is a low-voltage type of track, track lighting on a wall must be installed at least _____.

5' above the floor

The total rating of utilization equipment fastened in place, other than luminaires, shall not exceed ____ of a multiple outlet branch circuit rating.

50%

In general, the maximum sidewall load on any raceway run should be _____.

500 pounds/foot of bend

In other than dwelling units, GFCI protection shall be provided for all 15A and 20A, 125V, single-phase receptacles installed within ____ ft from the top inside edge of the bowl of a sink.

6

in a split phase motor, how much greater is the starting curre t when compared to the full load current

6 to 8 times

If a transformer has 200 turns in the primary, 100 turns in the secondary, and 150VAC applied to the primary, the voltage across the secondary is _____.

75VAC

Rod and pipe grounding electrodes shall not be less than ____ in length.

8 ft

A delta-connected motor has _____.

9 leads

For a separate building or structure supplied by a separately derived system when overcurrent protection is not provided for the supply conductors to the building/ structure as permitted by 240.21(C)(4), the installation shall be ____ in accordance with 250.30(A).

AFCI protected

The metal water piping system(s) installed in or attached to a building or structure [250.104(A)(3)] shall be bonded to ____.

Any of these

What type of fitting should be used for EMT in a wet location?

Compression

Which of the following are defined by the NEC® as separate portions of a conduit that provide access through a removable cover to the interior of the system at a junction of two or more sections?

Conduit bodies

Which of the following is an HID ballast category?

Constant wattage autotransformer

For a given number of poles, which of the following determines the speed of an AC motor?

Frequency

Part III of Article 100 contains definitions which are applicable to ____.

Hazardous (Classified) Locations

when used outdoors, photosensors should be aimed due

North

Which of the following is one of the most common types of wire-pulling rope on the market today?

Nylon

Which of the following are often used in conjunction with time clocks to turn off lighting when it is no longer needed?

Photosensors

Which of the following is a type of bending shoe?

Segmented

Energy legislation promotes the replacement of full-wattage fluorescent lamps with higher efficiency types, such as _____.

T-5s

Which type of conduit body does not provide a change in direction but may be used as a pulling point in a conduit run that has bends totaling more than 360°?

Type C

Which of the following is true regarding the storage and handling of lighting fixtures?

Wear gloves when handling fixtures to protect finished surfaces.

Which motor should be used for applications that require frequent starts without overheating the motor?

Wound rotor induction motor

Before starting a cable pull, make sure that _____.

all communications equipment is in working order

A hybrid system is comprised of multiple power sources, such as ____, but not the utility power system.

all of these

All ____ shall be covered with an insulation equivalent to that of the conductors or with an identified insulating device.

all of these

Separately installed pressure connectors shall be used with conductors at the ____ not exceeding the ampacity at the listed and identified temperature rating of the connector.

ampacities

Where exposed to the weather, raceways enclosing service-entrance conductors shall be ____ for use in wet locations and arranged to drain.

approved or listed

Where practicable, rod, pipe, and plate electrodes shall be installed ____.

below permanent moisture level

The ends of 1,000 kcmil conductors can be trimmed using _____.

cable cutters

A typical constant-torque load would be a(n) _____.

conveyor

Light enters the eye through a transparent layer called the _____.

cornea

The self-induced voltage across an inductance is produced by a change in

current with respect to time

NEMA and IP classify pull and junction boxes according to the _____.

degree of protection from the elements they provide

which type of ballast has the highest efficiency

electronic instant start

Surrounded by a case, housing, fence, or wall(s) that prevents persons from accidentally contacting energized parts is called "____"

enclosed

The stationary magnet of a DC motor is represented by the _____.

field poles

The NEC is ____.

for the practical safeguarding of persons and property

The ideal device for lifting and transporting cable reels is a _____.

forklift

According to the power triangle, the apparent power is _____.

greater than the true power

120V, single-phase, 15A and 20A branch circuits supplying outlets and devices installed in ____ of hotels and motels shall be protected by any of the means described in 210.12(A)(1) through (6).

guest rooms

opening the secondary circuit of a current transformer under load will cause a dangerous level of

induced high voltage

The opposing force that an inductor presents to the flow of alternating current is called _____.

inductive reactance

The conductors connected to the direct-current input of an inverter for PV systems form the ____.

inverter input circuit

Dog legs can be avoided when making offset bends by _____.

maintaining the centerline for all bends

A wire that is run along with integral to a cable or conductor to provide mechanical support for the cable or conductor is a ____.

messenger wire

Horsepower is used to rate the _____.

output capacity of a motor

NFPA 70E, Standard for Electrical Safety in the Workplace, provides guidance, such as determining severity of potential exposure, planning safe work practices, are-flash labeling, and selecting ____

personal protective equipment

The Code does not cover installations under the exclusive control of an electrical utility such as ____.

service drops and laterals

Each disconnecting means shall be legibly marked to indicate its purpose unless located and arranged so ____.

the purpose is evident

according to NEMA definitions, which of the following is a type of open motor?

weather-protected

Electrical hazards often occur because the initial ____ did not provide for increases in the use of electricity and therefore wiring systems become overloaded.

wiring

The most important tool for supervising a high-force cable pull is _____.

working communications equipment

In an inductive AC circuit, when the applied voltage is at its maximum negative value, the current is _____.

zero

if the time for one cycle is 0 1 second, the frequency is

10hz

Which of the following provides high voltage across the lamp's electrodes at startup, causing them to emit electrons

Instant-start ballast

which of the following are often used in conjunction with time clocks to turn off lighting when it is no longer needed?

Photosensors

the stationary magnet of a DC motor is represented by the

field poles

Ultrasonic occupancy sensors are triggered by _____.

motion

The size of the grounding electrode conductor for a building or structure supplied by a feeder shall not be smaller than that identified in ____, based on the largest ungrounded supply conductor.

250.66

The vertical clearance of final spans of overhead service conductors above, or within ____ ft measured horizontally of platforms, projections, or surfaces that will permit personal contact shall be maintained in accordance with 230.24(B).

3

The minimum working space on a circuit for equipment operating at 750 volts-to-ground, with exposed live parts on one side and grounded parts on the other side of the working space is ____.

4 ft

____ at other than dwelling units shall be legibly field marked with the maximum available fault current, include the date the fault-current calculation was performed, and be of sufficient durability to withstand the environment involved.

Service equipment

The power factor can be defined as the ratio of true power to _____.

apparent power

The product of the source voltage and the total current is _____.

apparent power

When making concentric bends in conduit of different sizes, the first step in calculating the radius of a bend is to _____.

determine the radius of the innermost bend

Connected (connecting) to ground or to a conductive body that extends the ground connection is called "____".

grounded

To discourage unauthorized entry, handhole covers must be _____.

heavier than 100 pounds or require tools to open

One of the characteristics of aluminum conduit is that it _____.

is lightweight

When making bends on short lengths of conduit, the shoe may be prevented from creeping by _____.

screwing a coupling onto the conduit

A "service drop" is defined as the overhead conductors between the utility electric supply system and the ____.

service point

A conduit run must pass over a pipe then over a rectangular duct. This will require a total of.....

seven bends

Service-entrance and overhead service conductors shall be arranged so that ____ will not enter the service raceway or equipment.

water

If the phase angles of two sine waves are both 0 degrees, then the waves _____.

are in phase

Outside feeder tap conductors can be of unlimited length without overcurrent protection at the point they receive their supply if the tap conductors _____.

are protected from physical damage

The primary method of varying the speed on a DC shunt motor is to adjust the voltage and current on the field winding or the _____.

armature

Type MC cable provides an effective ground-fault current path and is recognized by the NEC as an equipment grounding conductor when ____.

it contains an insulated or uninsulated equipment grounding conductor in compliance with 250.118(1)

Overhead service conductors shall have a minimum clearance from final grade of ____ above areas or sidewalks accessible only to pedestrians, measured from final grade or other accessible surface where the voltage does not exceed 150 volts to ground.

10 ft

Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ____ conductors at the point where the branch circuit originates.

ungrounded

For a constant-torque load, the horsepower increases and decreases _____.

in direct proportion to the speed

for a constant-torque load, the horsepower increases and decreases

in direct proportion to the speed

DC injection braking is used on

the stationary windings of AC motors

a device that uses electromagnetic induction to transfer electrical energy from one circuit to another is a(n)

transformer

PVC expansion couplings are seldom required in _____.

underground installations


Set pelajaran terkait

IT101 Chapter 12: Implementing Business/IT Solutions

View Set

NURA 308 AH 1 Practice Questions Cardiovascular

View Set

Physics Concept Questions Chapter 4-6

View Set

IBM Generative AI Fundamentals Specialization

View Set

Caesar's English Book 1 Lesson 16

View Set

PREPARATION AND ADMINISTRATION OF MEDICATION

View Set

NS 332 Fundamentals Final Quizlet

View Set