EESTX 106 Final
What is the diameter in inches of a T-8 fluorescent lamp?
1"
A 2,000A frame circuit breaker has a range of _____.
1,200 to 2,000 amps
What is normally the highest short circuit current in residential applications?
10,000A
The frame size of a 20A circuit breaker is _____.
100A
In a feeder circuit with no motor load, a time-delay fuse must be sized for _____ percent of the continuous load.
125
Given a cable tray that is available in standard widths of 6, 12, 18, 24, and 36 inches, what is the minimum width of a 3-inch deep cable tray used for the following cables that are all 4/0 or larger: two 1.75-inch diameter; and four 2.5-inch diameter?
18"
The heart is likely to stop when exposed to a current above _____.
200mA
The expected weight of an installed cable tray system is 200 pounds. Each support must be capable of carrying _______ .
250 lbs
Type S plug fuses are available with capacities up to _____ amps.
30
Type S fuses are available in sizes up to _____.
30A
Every circuit breaker must have its interrupting rating shown on the circuit breaker, unless it is rated for _____.
5000A
What is the highest voltage rating for circuit breakers used on DC systems that UL recognizes?
600V
The interrupting rating of an FH-type circuit breaker is _____.
65,000A
When conductors 1/0 through 4/0 are run in ladder-type trays, the maximum rung spacing must not exceed _____.
9"
Choose the correct statement.
A GFCI will open a circuit if a current imbalance of greater than 6mA is detected
Choose the correct statement
A cable tray support should be designed to provide no less than 125% of the combined weight of the tray and cable.
Choose the correct statement.
A compatible nonmetallic cable tray is permitted in corrosive areas.
Which of the following best describes the type of fitting that will be used with a solid cover cable tray?
A cover clamp
Which of the following best describes a dual-element fuse?
A fuse having an overcurrent limit and a time delay before activation
Which of the following branches in four different directions?
A horizontal cross
Choose the correct statement.
Cable tray is typically available in 12' and 24' lengths.
Which of the following is an NEC requirement for grounding and bonding cable tray installations ?
Cable tray sections must be bonded
When a circuit breaker trips, its handle moves to the _____ position
Center
A device that trips when a fault current to ground is 6mA or more is designated by UL as _____.
Class A
Which of the following statements is TRUE requiring ampacity adjustments of conductors in cable tray?
Conductors in cable tray use the same ampacity tables as other conductors
Which of the following HID ballasts provides improved dip tolerance?
Constant-wattage autotransformer
Choose the correct statement
Corrosion protection is required for metal cable trays used in corrosive atmospheres.
Which of the following provides a curved surface for the cable to follow as it passes from the cable tray?
Dropout plate
A center rail cable tray system is likely to be used to support cables in a power distribution system in a factory
False
A time delay fuse reacts to normal overcurrents and high fault currents in the same way.
False
Barrier strips are used to separate different types of cable tray
False
During a break period, it is acceptable to penetrate an on-the-ground safety barrier.
False
Feed-through GFCI receptacles are designed to interrupt current at one outlet and feed normal current through the circuit to the remaining outlets.
False
Incandescent lamps use a universal, twist-in base.
False
It is acceptable to place electrical cable in the same tray as gas or water pipes.
False
Single-element cartridge fuses are commonly used in motor control circuits.
False
The cable fill requirements for installation of multiconductor cable in solid bottom cable tray are the same as those for open cable tray.
False
The symbol list on drawings and specifications for a cable tray system must conform to an industry-wide standard.
False
The terms overload current and short circuit mean the same thing.
False
When non-time-delay fuses are being used in a motor circuit with fuse protection only, the fuse should be sized for 150% of the full-load current.
False
Which of the following best describes where the NEC® allows the use of Edison-base fuses?
For replacements in existing installations
When a common molded-case circuit breaker trips, in what position will the operating handle be?
Halfway between the On and Off positions
The voltage rating of a fuse in a circuit can be _____ than the circuit voltage.
Higher
Choose the correct statement.
If a conductor is rated for 15 amps, the fuse should be no larger than 15 amps.
Choose the correct statement.
In a center-hung support system, the cable tray is hung from a single threaded rod along with channel or Unistrut . ®
Conductors size 4/0 and larger in a cable tray must be _______ .
Installed in a single layer
When cable exits downward from a tray without a dropout plate, which of the following could occur?
Insulation damage
Which of the following is TRUE regarding a dual-element fuse?
It contains a fuse link connected in series with an overload element.
Choose the correct statement.
It is important that all circuit components be compatible as far as voltage and current ratings are concerned.
On renewable cartridge fuses, which part of the fuse is normally renewed?
Link
Choose the correct statement.
Multiconductor cables 4/0 and larger must be placed in a single layer with no cables on top of them.
The requirements for overcurrent protection can be found in _____.
NEC Article 240
Cable tray is covered in _____.
NEC Article 392
Cable tray ampacity information can be found in _____.
NEC Section 310.15
Where is the ampere rating normally marked on circuit breakers?
On the handle
Which of the following is TRUE regarding overload current?
Overload current is confined to normal conductive paths.
Which of the following is a violation of NEC Section 300.8?
Placing an instrumentation air line in the same tray with electrical conductors
What is the name for the nerve terminals in the eye that are stimulated by light on the retina and provide a path by which the light impulses are transferred from the eye to the brain?
Rods and Cones
Choose the correct statement.
Single-element cartridge fuses respond rapidly to short circuit currents.
Which of the following types of drawings helps when sizing fuses for a given application?
Single-line schematic
Which of the following statements is TRUE regarding cable splices in cable trays?
Splices must be insulated using NEC-approved methods
Which of the following is the most important consideration when working with overcurrent protection devices?
The correct interrupting capacity
Choose the correct statement.
The current-limiting mechanism of a current-limiting circuit breaker reacts instantaneously to a large fault current. The conventional mechanism opens when the fault current has been dissipated.
Which of the following is TRUE with regard to circuit breakers?
The interrupting capacity is based on its rated voltage.
Which of the following best describes how closely packed cables will be affected when energized?
Their efficiency will be decreased.
Which of the following occurs when the load applied causes the fibers on the tension side of the rung to stretch and permanently deform?
Transverse failure
A cable tray in an industrial setting may be located on a pipe rack used to carry steam or other fluids
True
Dimming ballasts for fluorescent lamps are usually of the electronic type.
True
Under some conditions, grounded metallic cable tray may be used as an equipment grounding conductor
True
All multicolor cables operating at or above 1000V must be separated by a solid divider from cables operating under 1000V, EXCEPT for ______ .
Type MC
What must be used in conjunction with Type S plug fuses when they are installed in a fuse holder?
Type S adapter
What kind of mounting is often used in tunnels and other underground installations?
Wall mounting
Circuits in which the breaker must be highly sensitive to amperage changes should use a(n) _____.
ambient-compensating circuit breaker
The term AIC refers to the _____.
amperage interrupting capacity
NEC Section 240.85 covers circuit breaker _____.
applications
A _____ is used to bind a raw metallic edge over which a cable might pass.
barrier strip cable protector
The main purpose of vertical adjustment splice plates is to _____.
change the elevation in a run of cable tray
A _____ is used to carry cables from the tray to the termination point.
channel
In a system where selective coordination is applied, the protective device _____ the fault source will open first.
closest to
The time-current relationship for a number of overcurrent devices connected in series is known as _____.
coordination
The method of supporting cable trays using threaded rods and hanger clamps is known as _________ .
direct rod suspension
A barrier strip is a _____.
division strip installed in a raceway to separate certain types of cables
A section of cable tray that makes a single horizontal 90° turn is known as a(n) _____.
elbow
The most desirable method of exiting cable from a cable tray ______ .
from the end of the tray using a dropout plate
A tungsten halogen lamp is likely to contain _____ gas.
iodine
Symbols used to show cable tray systems on working drawings are explained in the
legend
Overloads are often caused by _____.
motors starting
Cable tray in a corrosive location is most often constructed of _____.
non matallic material
Areas requiring voltage isolation are likely to use _____.
nonmetallic cable tray
Tray splices should be located within _____ of the span's distance from the support.
one-fourth
Cable in vertical trays should be supported _____.
per the manufacturer's recommendations
Circuit breakers and fuses operate in a similar manner as a boiler's _____.
pressure relief valve
Dropout plates are used to _____.
protect cable exiting the tray
A cable hanger elbow is used to ________ .
suspended cables in long vertical runs
When a cable tray section branches off from a main section in two 90° turns, the section is called a(n) _____.
tee
When a cable tray system must be protected from dropping objects that may damage the cable, a _____.
tray cover is used
Circuit breakers have _____ type(s) of current ratings.
two
Cartridge fuses used for branch circuit protection must be marked with the ampere rating, interrupting rating (if other than 10,000A), and the _____.
voltage rating
Which type of lamp produces light that is concentrated in the yellow portion of the visible light spectrum?
Low-pressure sodium
Which type of fluorescent ballast is used with a lamp that has low-resistance electrodes that remains energized when the lamp is energized?
Rapid-start
