Chapter 211/212
An AC generator produces ___ cycle(s) per revolution for each pair of poles.
1
A recessed incandescent luminaire is to be installed in a ceiling grid system. The shortest 14 AWG "fixture whip" permitted, between a 4-square 20-amp branch circuit box and the wiring compartment of the luminaire, is ___. Note that the 14 AWG wires are smaller than the 20-amp circuit breaker can protect and are therefore "tap conductors" by definition.
1.5 feet
The magnetic field around a conductor collapses (zero strength) ___ times per second when 60 Hz AC current is passing through the conductor.
120
The ampacity of each conductor of a 16/3 AWG multiconductor Type SPT-2 flexible cord, used to supply utilization equipment which is fastened-in-place, is ___ amps. See NEC® T. 400.4 for available sizes and which conductors are current carrying.
13
A 208-volt, 1-ph piece of equipment is to be connected with SOO flexible cord. What is the smallest AWG size cord that can be used to connect the equipment? The maximum load on any one conductor is 17 amps.
14
Among the sizes listed below, the damaged power cord on a 120-volt appliance can be replaced with a 6-ft length of flexible SJO cord not smaller than ___ AWG where the appliance is to be connected to a 15-A branch circuit.
14
Amusement rides and amusement attractions shall be maintained not less than ___ feet in any direction from overhead conductors operating at 600 volts or less.
15
Portable structures at a circus shall not be located under or within ___ feet horizontally of conductors operating in excess of 600 volts.
15
Control voltage for permanent amusement attractions shall be a maximum of ___ volts, nominal, ac to ground.
150
Handholes are not required in metal parking lot light poles if the base is hinged and the pole is ___ feet or less in height.
20
When connected to a 120/240-volt, 3Ø piece of equipment a 10 AWG SJO flexible cord can carry ___ amps. The equipment requires a neutral connection and this conductor should be counted as a current-carrying conductor.
20
The 8-32 screws in an octagonal 4/0 box are permitted to support a luminaire provided the luminaire weight does not exceed ___ kg.
23
When connected to a 1Ø piece of equipment that operates at 240 volts, a 12 AWG SJO flexible cord can carry ___ amps.
25
If a circuit is operating at 208 volts (RMS) the peak value of the voltage is ___ volts.
294.2
Any branch circuit conductor located within ___" of a ballast, within a ballast compartment, shall have an insulation rating not lower than 90ºC.
3
The installation shown above in Figure 211.2 violates the provisions of ___ in the NEC ®. Wiring Method 1 is UF cable and Wiring Method 2 is Schedule 40 PVC.
300.5
The minimum branch-circuit rating for an individual branch circuit that is used to supply a fastened-in-place appliance is ___ amps. The marked rating (equipment nameplate) on the appliance is 35 A. The appliance is not continuously loaded.
35
The smallest circuit breaker that can be installed in a panel is ___ Amp. The circuit supplies power to a 240-volt, single-phase, 6.6 KW, 50-gallon water heater.
35
A 3Ø piece of equipment has a nameplate rating of 54 amps at 240 volts 3-phase. The equipment needs to be connected with STO flexible cord. The cord will contain 3 circuit conductors + a green insulated conductor. The smallest cord you can use is ___ AWG.
4
The maximum length of a flexible cord used to connect data-processing equipment to a branch circuit outlet box is ___.
4.5 Meters
A ceiling-mounted luminaire that weighs 5 pounds is permitted to be mounted to and supported by a ___.
4/0 box
Within sight is visible and no more than ___ feet from the object.
50
At a carnival, portable termination boxes installed outdoors, shall be of weatherproof construction and mounted so that the bottom of the enclosure is not less than ___ above the ground.
6"
A 100-gallon boiler is to be installed to supply hot water to the restrooms in an office building. The boiler is rated for 9.8 KW at 240 volts 1-phase. The minimum size of the boiler branch circuit breaker that can be installed in the panel is ___ amps.
60
In the United States ___ is the standard number of cycles per second of generated power.
60
Normally, AC power in the United States operates at ___ cps (cycles per second).
60
Where operating in the United States, AC voltage reaches a positive peak ___ times during 1 second.
60
Where 6 AWG/7-conductor Type G flexible cable is used to supply fastened-in-place utilization equipment, it has an ampacity of ___ amps. See NEC® T. 400.4 for available sizes. This equipment has a metal enclosure and the connection terminals have 75ºC ratings.
62
A certain piece of equipment is to be connected with SOO flexible cord. The equipment requires 2 ungrounded and 1 grounded conductors. What is the smallest AWG size cord that can be used to connect the equipment? All conductors should be counted as a current carrying. The maximum load on any one conductor is 31 amps. The equipment will operate continuously.
7
A 100-gallon boiler is to be installed to supply hot water to the restrooms in an office building. The boiler is rated for 7.6 KW at 240 volts 1-phase. The circuit for the boiler originates in a 120/208-volt, 3Ø, 4-wire panelboard. The minimum size THHN/THWN copper wire that can be installed between the required disconnect switch and the boiler is ___ AWG. Don't forget to check the requirements of 240.4(D).
8
A 60-gallon water heater is to be installed to supply hot water to the restrooms in an office building. The water heater is rated for 8.2 KW at 240 volts 1-phase. The minimum size THHN/THWN copper wire that can be installed between the required disconnect switch and the water heater is ___ AWG.
8
The smallest THHN/THWN copper circuit conductors that can be used for a 240-volt, single-phase, 8.5 KW, 50-gallon water heater where connected to a circuit breaker is ___ AWG.
8
If a circuit breaker protecting a 60 Hz circuit can operate on a short circuit in one-half of an electrical cycle, this is ___ mS.
8.33
Per 220.43(B) in the NEC ®, ___ VA must be allocated for the lighting track when determining the calculated load on the service where a 12' length of lighting track is installed in the conference room in an office building.
900
The "J" designation in any of the "S-type" flexible cords designates ___.
A junior size
The discovery that charged bodies attract or repel each other is called ___.
Coulomb's Law of Charges
Connection ___, shown above in Figure 211.4, can be used where the cover on the luminaire terminal box is stamped "Suitable for thru-wiring".
Either I or II
Luminaires (such as "down lights") that are recessed in a grid-type ceiling are required to be secured to the building structure, according to the NEC ®.
False
The NEC® prohibits mounting luminaires directly to a tree.
False
___ materials, such as soft iron, can be easily magnetized.
Ferrous
Standard lighting track shall not be equipped with ___.
General-purpose receptacles
___-grade receptacles are the highest grade receptacles manufactured by the electrical industry.
Hospital
___ is a type of lamp used in an HID luminaire. I. Mercury-vapor II. Metal halide III. Nickel cadmium
I & II only
Refer to Figure 211.10. You are to connect the dishwasher. A dedicated circuit has been run to a receptacle that is located under the sink. The 2-pole, 3-wire receptacle is flush-mounted in the sheetrock wall under the sink. Your two installation options are: I. Install a flexible cord with a grounding-type attachment plug. There will be 33 inches of cord between the back of the dishwasher and the receptacle. II. Replace the receptacle with a handy box extension ring and a single-pole switch with a cover, and run Type MC cable from the e-ring to the dishwasher. Which installation method, shown above, violates the provisions of NEC® Article 422?
I only
Where a luminaire is listed for installation in a damp location, it can be installed in a ___ location. I. wet II. dry III. damp
II & III only
The power to the fan, shown below, is to be supplied from a 4/0 box that is not listed for fan support. The installation options are: I. Using a 1/ 2" threaded rod suspended vertically from the building structure, securely attach the 4/0 box to the rod using hex nuts. Then directly connect the fan to the 4/0 box using 8-32 machine screws. II. Suspend two parallel 1/ 4" threaded rods vertically from the building structure so that these pass through the 4/0 box and extend below the ceiling finish. Attach the 4/0 box to these rods with hex nuts. Attach the canopy, with hex nuts, to the rods that extend below the ceiling. Which installation option, shown above, satisfies the requirements of 314.27(C) in the NEC ®?
II Only
Permanent magnets are used in the construction of ___ motors. I. AC II. DC
II only
Refer to Figure 211.6. After removing the receptacle from its package, you are going to check it with an ohmmeter. If the leads of the ohmmeter are placed between Points D and G, the meter should indicate ___ ohms.
Infinite
___ shall not support luminaires weighing over 6 lb.
Lampholders
A(n) ___ is a complete lighting unit consisting of a light source such as a lamp or lamps, together with the parts designed to position the light source and connect it to the power supply.
Luminaire
An atom with an equal number of protons and electrons is said to be electrically ___.
Neutral
Which of the conversion formulas listed below is correct?
RMS = Peak × 0.707
Which of the flexible cables or cords listed below could be used to connect a piece of equipment that operates at 480 volts 3-ph?
SEO
A listed appliance is manufactured with a 16 AWG flexible power cord that is used for connection to a receptacle. The nameplate on the appliance contains the information: "Maximum 15 A". This appliance is considered to be protected by a 15-amp branch circuit breaker.
T rue
Fluorescent luminaires are connected end-to-end as shown below. The "Home Run" conduit contains circuits HA-16, 18, 20 (3 "hots" + 1 neutral) and nightlight (NL) circuit HA-2. All of these circuits originate in a 277/480-volt, 3Ø, 4-W panelboard. These conductors pass through the luminaires and the circuits serve the luminaires as indicated on the illustration. Which of the following statements is true?
This installation is permitted by NEC 410.64(C)
Generally, flexible cords and cables shall be installed in continuous lengths without splices or taps.
True
Temporary magnets lose their magnetism as soon as the magnetizing force is removed.
True
Where flexible cord is used to connect a kitchen food waste disposer to the branch circuit the cord can be connected by which of the following methods?
Using a listed 2-P, 3-wire cord cap inserted into a receptacle that is connected to the branch circuit.
Which of the formulas, shown below, is correct to find the equivalent of 3 caps in a parallel circuit?
answer is picture
Which of the formulas, shown below, is correct to find the equivalent of 3 inductors in a parallel circuit?
answer is picture
Which of the symbols, shown below, is used to represent a resistor in a schematic circuit?
answer is picture
Which of the symbols, shown below, is used to represent an AC power source in a schematic circuit?
answer is picture
Which of the symbols, shown below, is used to represent an inductor in a schematic circuit?
answer is picture
Which of the flexible cords or cables listed below can be used in dry locations?
any of these
When power is ___ a solenoid valve controlling the flow of water into a clothes washing machine the valve opens and allows water to flow.
applied to
The "W" suffix (last letter) in any of the "S-type" flexible cords designates that the cable ___.
as suitable for wet locations
Low-voltage equipment and instruments shall have ___.
attachment plugs that do not allow interchangeability with higher voltage circuits
An electric-discharge luminaire utilizes a ___ for the operation of the lamp.
ballast
As the distance between two magnetic poles increases, the force of attraction (strength of the magnetic field) ___.
decreases
The three most common types of permanent magnets include all except ___.
electromagnets
A capacitor is made up of a pair of conductive plates separated by a thin layer of ___ material.
insulating
The strength of the magnetic field around a coil (or winding) ___ when DC voltage is applied.
is constant
In an inductive circuit, the current ___ the applied voltage.
lags
A ___ is a device that attracts iron and steel because of the molecular alignment of its material.
magnet
A coil of wire, when carrying current, acts like a ___.
magnet
Magnetic flux comprises the invisible lines of force that make up the ___.
magnetic field
The two axes of alternating voltage or current on a sine wave are a graphic representation of ___.
magnitude and time
A customer wants to install 120-volt track lighting on the wall 2 feet above a countertop. The top of the countertop is 32 inches AFF. Does the NEC® permit this installation?
no
Luminaires are installed outdoors under an open porch of a one-family dwelling. The luminaires are marked "Suitable for Wet Locations." Does this violate the provisions of Article 410 of the NEC ®?
no
Which of the symbols, shown below, is used to represent a DC power source in a schematic circuit?
none of these
Where stage smoke ventilators are released by an electrical device, the circuit operating the device shall be ___ and shall be controlled by at least two externally operable switches.
normally closed
X-Ray equipment shall have a disconnect that is ___.
operable from a readily accessible location.
Capacitors in series add like resistors in ___.
parallel
Inductors in parallel add like resistors in ___.
parallel
Meter leads must have an insulation that is rated for the ___ voltage of a circuit.
peak
As a safety consideration, when power is ___ a solenoid valve controlling the flow of natural gas to the gas-fired cooking appliances in a restaurant, the valve closes and stops the gas flow to the appliances.
removed from
The graphic representation of AC voltage or current values over a period of time is a ___.
sine wave
The peak-to-peak value of a sine wave is ___ the maximum positive peak value.
twice
A unit switch is the ON/OFF switch on an appliance that disconnects all ___ conductors.
ungrounded