2B
The disconnecting means for the controller and motor shall open all ungrounded supply conductors.
True
Where more than one motor disconnecting means is provided in the same motor branch circuit, at least one of the disconnecting means shall be readily accessible.
True
The terminals of a motor can be identified using a battery and a(n):
voltmeter
A polyphase synchronous motor has three stator windings that are:
120° apart
Conductors supplying several motors shall not be sized smaller than _____ percent of the full-load current rating of the highest rated motor, plus the sum of the full-load current ratings of all other motors in the group, plus the ampacity of other loads.
125
The raceway or cable for tap conductors to recessed luminaires shall have a minimum length of _____ in.
18
Which color temperature produces a balance between warmth and coolness?
3,500K
Motor control circuit conductors that extend beyond the motor control equipment enclosure shall have short-circuit and ground-fault protection sized not greater than _____ percent of the value specified in Table 310. 15(B)(16) for 60º C conductors.
300
What is the frequency of an AC waveform that completes 20 cycles per half second?
40Hz
In a split-phase motor, how much greater is the starting current when compared to the full- load current?
6 to 8 times
Incandescent luminaires that have open lamps, and pendant-type luminaires, shall be permitted in clothes closets where proper clearance is maintained from combustible products.
False
Which of the following is most likely to use dynamic braking?
Forklift
Which of the following provides high voltage across the lamp's electrodes at startup, causing them to emit electrons?
Instant-start ballast
The junction box and recessed lighting fixture should be separated by a minimum distance of:
1'
The power factor of an induction motor at no-load conditions can be as low as:
15%
Lighting track shall not be installed less than _____ ft. above the finished floor except where protected from physical damage or where the track operates at less than 30V rms, open-circuit voltage.
5
Reactive power is always:
90° out of phase with true power
Which of the following is an HID ballast category?
Constant wattage autotransformer
If the phase angles of two sine waves are both 0 degrees, then the waves:
are in phase
The motor disconnecting means shall not be required to be in sight from the motor and the driven machinery location, provided _____.
the controller disconnecting means is lockable, in accordance with 110. 25 locating the motor disconnecting means within sight of the motor is impractical locating the motor disconnecting means within sight of the motor introduces additional or increased hazards to people or property
DC injection braking is used on:
the stationary windings of AC motors
Unless overload protection is provided by other approved means, the minimum number of overload units required for a three-phase alternating-current motor is _____.
three
A device that uses electromagnetic induction to transfer electrical energy from one circuit to another is a(n):
transformer
A separate overload device used to protect continuous-duty motors rated more than 1 hp shall be selected to trip at no more than _____ percent of the motor nameplate full-load current rating if marked with a service factor of 1. 15 or greater.
125
Several motors are permitted to be supplied by a single branch circuit as long as each motor is no larger than:
1hp
What is the step-down turns ratio of a transformer with 200 turns in the primary and 100 turns in the secondary?
2:1
Overcurrent protection for motor control circuits shall not exceed _____ percent if the conductor is based on Table 310. 15(B)(17) and does not extend beyond the motor control equipment enclosure.
400
What is the true power in a 2A series RL circuit with a 100Ω resistor?
400W
For stationary motors of 2 hp or less and 300V or less on ac circuits, the controller can be an ac-rated only general-use snap switch where the motor full-load current rating is not more than _____ percent of the rating of the switch.
80
Which of the following motors is used when the required starting torque is high and speed control is desirable?
Compound
Which of the following materials absorbs the most light?
Dark red bricks
A type of system that can be used to control both lighting and HVAC equipment is a(n):
EMS
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
The capacitor-start motor is the single-phase motor type that has the:
highest starting torque
When used outdoors, photosensors should be aimed due:
north
A flange hanger is commonly used with a:
suspended fixture
Chandeliers are a type of:
suspended lighting fixture
Transformers in which the primary and secondary voltages are 180 degrees out of phase are known as:
unlike-wound transformers
Motors shall be located so that adequate _____ is provided and so that maintenance, such as lubrication of bearings and replacing of brushes, can be readily accomplished.
ventilation
Which of the following motors is the best installation choice for an application requiring adjustable speeds?
Shunt DC
Which of the following motors provides constant speed from no-load conditions to full-load conditions?
Synchronous
Energy legislation promotes the replacement of full-wattage fluorescent lamps with higher- efficiency types, such as:
T-5s
A branch-circuit overcurrent device can serve as the disconnecting means for a stationary motor of 1/8 hp or less.
True
Each motor shall be provided with an individual controller.
True
Outdoor luminaires and associated equipment can be supported by trees.
True
Where the motor short-circuit and ground-fault protection devices determined by Table 430.52 do not correspond to the standard sizes or ratings, a higher rating that does not exceed the next higher standard ampere rating shall be permitted.
True
Which of the following is true regarding the storage and handling of lighting fixtures?
Wear gloves when handling fixtures to protect finished surfaces.
The formula for inductive reactance is:
XL = 2πfL
Poles over 20 ft. in height above grade, without a hinged base, that support luminaires shall have an _____.
accessible hand hole (sized 2 in. x 4 in. ) with a cover suitable for use in wet locations equipment grounding terminal that is accessible from the hand hole
A horsepower-rated _____ having a horsepower rating not less than the motor rating shall be permitted to serve as the disconnecting means.
attachment plug and receptacle flanged surface inlet and cord connector
A _____ rated in amperes shall be permitted as a controller for all motors.
branch-circuit inverse time circuit breaker molded case switch
In a circuit that has both capacitance and resistance, the current will lead the voltage:
by some angle between 0° and 90°
The disconnecting means for a motor controller shall be designed so that it cannot _____ automatically.
close
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
A _____ shall be located in sight from the motor location and the driven machinery location.
disconnecting means
Overload devices are intended to protect motors, motor control apparatus, and motor branch-circuit conductors against _____.
excessive heating due to motor overloads excessive heating due to failure to start
The stationary magnet of a DC motor is represented by the:
field poles
If a motor disconnecting means is a motor-circuit switch, it shall be rated in _____.
horsepower
The opposing force that an inductor presents to the flow of alternating current is called
inductive reactance
A feeder supplying fixed motor load(s) shall have a protective device with a rating or setting _____ branch-circuit short-circuit and ground-fault protective device for any motor in the group, plus the sum of the full-load currents of the other motors of the group.
not greater than the largest rating or setting of the
The motor disconnecting means for a motor shall _____ whether it is in the open (off) or closed (on) position.
plainly indicate
Electric-discharge and LED luminaires supported independently of the outlet box shall be connected to the branch circuit through _____.
raceways Type MC, AC, MI, or NM cable flexible cords
The value indicated in rpm on the nameplate is the:
rated full-load speed
Luminaires designed for end-to-end assembly, or luminaires connected together by _____, can contain a 2-wire branch circuit, or one multi-wire branch circuit, supplying the connected luminaires. One additional 2-wire branch circuit separately supplying one or more of the connected luminaires is permitted.
recognized wiring methods
The motor branch-circuit short-circuit and ground-fault protective device shall be capable of carrying the _____ current of the motor.
starting
The NEC® requires motor disconnecting means be:
within sight of the controller location
Lamp holders installed in wet locations shall be listed for use in _____ locations.
wet
Track lighting shall not be installed _____.
where likely to be subjected to physical damage in wet or damp locations
Article 410 covers luminaires, portable luminaires, lampholders, pendants, incandescent filament lamps, arc lamps, electric-discharge lamps, and _____, and the wiring and equipment forming part of such products and lighting installations.
decorative lighting products lighting accessories for temporary seasonal and holiday use portable flexible lighting products
An electric-discharge or LED luminaire or listed assembly can be cord connected if the luminaire is located _____ the outlet, the cord is visible for its entire length except at terminations, and the cord is not subject to strain or physical damage.
directly below
In an inductive AC circuit, when the applied voltage is at its maximum negative value, the current is:
zero
What is the current flow in a purely resistive AC circuit if the resistance is 15 ohms and the voltage is 150V?
10A
If the time for one cycle is 0. 1 second, the frequency is:
10Hz
The maximum rating or setting of an inverse time breaker used as the motor branch-circuit short-circuit and ground-fault protective device for a single-phase motor is _____ percent of the full-load current given in Table 430.248.
250
Which of the following are often used in conjunction with time clocks to turn off lighting when it is no longer needed?
Photosensors
Handholds in poles supporting luminaires shall not be required for poles _____ ft. or less in height above finished grade, if the pole is provided with a hinged base.
20
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
A delta-connected motor has:
9 leads
Which of the following is true regarding modular wiring systems?
Modular components are color-coded by voltage.
For general motor applications, the motor branch-circuit short-circuit and ground-fault protection device shall be sized based on the _____ values.
NEC Table
Which of the following will shorten the life of a filament in an incandescent lamp?
Operating at warmer temperatures
Motor control circuits shall be arranged so they will be disconnected from all sources of supply when the disconnecting means is in the open position.
True
Torque requirements for motor control circuit device terminals shall be a minimum of _____ lb-in. (unless otherwise identified) for screw-type pressure terminals used for 14 AWG and smaller copper conductors.
7
Motor controllers and terminals of control circuit devices shall be connected with copper conductors unless identified for use with a different conductor.
True
The type of high-intensity discharge (HID) lamp that has excellent color rendition is the:
metal halide lamp
A motor disconnecting means can be a listed _____.
molded case circuit breaker motor-circuit switch rated in horsepower molded case switch
Open motors having commutators or collector rings shall be located or protected so that sparks cannot reach adjacent combustible material. This shall not prohibit the installation of these motors _____.
on wooden floors
A motor can be provided with combined overcurrent protection using a single protective device to provide branch-circuit _____ protection where the rating of the device provides the overload protection specified in 430.32.
short-circuit ground-fault motor overload
Feeder tap conductors supplying motor circuits, with an ampacity at least one-third that of the feeder, shall not exceed _____ ft. in length.
25
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
Any exposed live parts must be guarded if they are operating at:
50V or more between terminals
Which type of ballast has the highest system efficiency?
Electronic instant-start
A 120V section of lighting track that is continuously loaded shall not exceed 12 ft in length, in accordance with 220. 43(B).
False
A motor controller shall open all conductors to the motor where not used as a disconnecting means.
False
Fluorescent lamps with a single pin at each end are known as:
instant-start lamps
The motor controller shall have horsepower ratings at the application voltage not _____ the horsepower rating of the motor.
lower than
Luminaires using a _____ lamp, that is subject to physical damage and installed in playing and spectator seating areas of indoor sports, mixed-use, or all-purpose facilities, shall be of the type that protects the lamp with a glass or plastic lens.
mercury vapor metal halide
Ultrasonic occupancy sensors are triggered by:
motion