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JATC Fiber Optics Exam With In-Depth Questions &
Model Answers (Newest Updated)
Fiber optics is used in cars to connect their electronic systems. ANSWER>>>> True
Copper networks can be converted to fiber optics using _____. ANSWER>>>> Media
converters Telephone networks have been converted to fiber, including long distance and metropolitan
networks, but fiber to the home (FTTH) is not yet feasible. ANSWER>>>> False
Which of the following communication systems typically use fiber-optic backbones?
ANSWER>>>> - CATV
- Cell phones
- Telephones
- Internet
In an industrial environment, fiber is most often used to _____. ANSWER>>>> Prevent
electromagnetic interference
An advantage of optical fiber is the fact that it is the most cost effective means of transporting
information over long distances. ANSWER>>>> True
The bandwidth and distance capability of optical fiber means that _____. ANSWER>>>> -
Less maintenance is required
- Fewer repeaters are needed
- Fewer cables are needed
- Less power is consumed by the network The protective gear every voice/data/video (VDV) installer must always wear is _____.
ANSWER>>>> Eye protection
Information on the safety of chemicals used in fiber optics are _____. ANSWER>>>> In
MSDS supplied by the manufacturer. Inspection microscopes can concentrate the light from a fiber into your eye causing serious
damage. ANSWER>>>> True
Bright red visible light is produced by a VFL that is safe to look at directly at the end of the fiber.
ANSWER>>>> False
A digital camera can see infrared light, so it can be used to determine if there is light present in
a fiber. ANSWER>>>> True
The wavelength of light used for most fiber-optic systems is in the _____ region and _____ to
the human eye. ANSWER>>>> - Infrared
- Invisible Multimode fiber has a larger core than single mode fiber measuring _____ microns in diameter.
ANSWER>>>> - 50 or 62.5 microns in diameter
In an optical fiber, the light is transmitted through the _____. ANSWER>>>> - Core
Rays of light transmitted in multimode fiber are called _____. ANSWER>>>> - Modes
The cladding of the fiber is stripped off the fiber when terminating. ANSWER>>>> False
What type of fiber optic cable would be used with a LED light source? ANSWER>>>> MM
Which of the following represents a single mode fiber size? ANSWER>>>> 9/125 microns
If a fiber optic cable has a "graded index" core, what type of fiber is it? ANSWER>>>> MM
"Thin strands of highly transparent glass or plastic that guide light" defines _____.
ANSWER>>>> - Optical fiber
The term "nanometer" is a measurement that is often used in fiber optics to express _____.
ANSWER>>>> Wavelengths of light
The diameter of an optical fiber is traditionally measured in _____/_____. ANSWER>>>> -
Microns/micrometers Multimode fiber systems operation at speeds of 1 gigabit per second or more for short lengths
use _____. ANSWER>>>> - Vertical cavity surface emitting lasers (VCSELs)
LED light sources have a very _____ spectra, while laser light sources have a very _____ spectra.
ANSWER>>>> - Broad
- Narrow What wavelengths would an F-P laser light source used for SM operate at for transmission over
fiber optic cabling? ANSWER>>>> 1300 and 1550 nm
What wavelengths are appropriate for use with MM fiber? ANSWER>>>> 850 and 1300 nm
What wavelengths are appropriate for use with SM fiber? ANSWER>>>> 1310 and 1550 nm
Light-emitting diodes (LEDs) have higher output power and bandwidth than lasers.
ANSWER>>>> False
The design of _____ MM fiber compensates for modal dispersion. ANSWER>>>> - Graded
index _____ light sources have a broad spectrum, suffering more chromatic dispersion than _____
light sources. ANSWER>>>> - LED
Which type of dispersion affects SM fiber as well as MM fiber? ANSWER>>>> Chromatic
The speed of light varies with wavelength, which causes _____. ANSWER>>>> - Chromatic
dispersion
SM fiber has _____ bandwidth than MM fiber. ANSWER>>>> - More
The _____ of a laser makes the effective bandwidth of MM fiber higher than LEDs.
ANSWER>>>> - Restricted launch
What is caused by varying speeds in each mode in multimode fiber? ANSWER>>>> - Modal
dispersion
Fiber bandwidth is limited by _____. ANSWER>>>> - Dispersion
The proper method of pulling optical fiber cables is to attach the pull wire or tape to the _____
of the cable. ANSWER>>>> - Strength members
Which type of cable is best suited for indoor installation when fibers are to be directly terminated inside a patch panel with adhesive/polish or pre polished splice connectors?
ANSWER>>>> - Distribution tight buffer cable
What absorbs the tension needed to pull fiber optic cable and provides cushioning for the
fibers? ANSWER>>>> Aramid yarn strength members
What provides additional protection to the fiber and allows for easier handling and direct
termination to the fiber? ANSWER>>>> 900 micron tight buffer coating
The first layer of protection of a fiber optic cable is the _____. ANSWER>>>> 250 micron
primary buffer coating Which of the following cables would be used for patch cord and backplane applications?
ANSWER>>>> Zipcord cable
What type of cable is a favorite where rugged cables are desirable or direct termination without
junction boxes, patch panels, or other hardware is needed? ANSWER>>>> Break-out cable
What type of cable may require installation of a breakout kit (also called a furcation or fan out
kit) for termination? ANSWER>>>> Loose tube cable
What connector color typically identifies an SM APC? ANSWER>>>> Green
The SC and LC connectors have different size ferrules and cannot be mated.
ANSWER>>>> True
The difference between a fiber-optic connector and a splice is _____. ANSWER>>>> -
Connectors are demountable, splices are permanent Which of the following connector types uses an 8 degree angle to prevent singlemode
reflectance? ANSWER>>>> APC
You may see other connector colors outside of the typical ones, especially for multimode.
ANSWER>>>> True
The connector with the best or lowest reflectance would be the _____. ANSWER>>>> - SC-
APC
What connector color is typically used to identify multimode? ANSWER>>>> Beige
What connector color is typically used to identify singlemode? ANSWER>>>> Blue
Fiber optic joints (connectors or splices) should have _____, _____, and _____.
ANSWER>>>> - Low loss
- Minimal reflectance
- High mechanical strength
Physical contact (PC) polish on connectors is designed to reduce _____. ANSWER>>>> -
Loss and reflectance When terminating fiber, what is used to precisely "break" the fiber to produce a flat end for
polishing or splicing? ANSWER>>>> Cleaver
When preparing a fiber for termination, what is stripped off of the fiber before placing it within
a connector? ANSWER>>>> Primary buffer coating
A _____ is a hard, sharp tool that scratches the fiber to allow cleaving. ANSWER>>>> -
Scribe Before terminating a fiber optic connector, make sure to slide the _____ onto the cable.
ANSWER>>>> - Boot
When injecting epoxy into a connector, how do you know when you have injected enough?
ANSWER>>>> A small bead of the epoxy will be seen coming out of the end of the ferrule
What is the first step when polishing an adhesive termination? ANSWER>>>> "Air polish" to
grind down the cleaved fiber
What type of splice utilizes index matching gel to minimize loss between two fibers?
ANSWER>>>> Mechanical splice
For mechanical splices, it's important to apply _____ on the fiber to keep the ends together
while crimping. ANSWER>>>> - Light pressure
What is the most common application for mechanical splicing? ANSWER>>>> Temporary
restoration When performing mechanical splices, what could be used during the splicing process to yield
more consistent and lower loss splices? ANSWER>>>> Cleaver
What can be used to optimize a mechanical splice for low loss? ANSWER>>>> Visual Fault
Locator The link loss budget analysis of a cable plant should be done to _____, _____, and _____.
ANSWER>>>> - Ensure the intended communications system will work on the cable plant
system
- Provide a pass/fail loss value for comparison to test values
- Ensure the cable plant has been properly installed In a basic fiber optic system, the transmitter converts a _____ signal into a _____ signal.
ANSWER>>>> - Electrical
The amount of optical power lost as light is transmitted through fiber, splices, and couplers is
defined as _____. ANSWER>>>> - Optical loss
Connectors at each end of the cable plant should not be counted when calculating the cable
plant loss. ANSWER>>>> False
What component can convert an electrical signal to or from an optical signal?
ANSWER>>>> Tranceiver
Fiber optic links generally use two fibers for full duplex (bidirectional) links.
ANSWER>>>> True
A fiber optic power meter measures absolute power in dBm (dB referenced to 1 mw) and, when
used with a light source, can measure insertion loss expressed in dB. ANSWER>>>> True
A visible light source (LED or flashlight) used to visually check fiber continuity and location of
faults is called a _____. ANSWER>>>> - Fiber tracer
What is used to inspect the end surface of a connector for faults such as scratches, polish, or
dirt? ANSWER>>>> Inspection microscope
What fiber optic test simulates actual system operation? ANSWER>>>> Optical Loss Test Set
(OLTS)
For insertion loss testing, the fiber optic test source MUST match the both _____ and _____ of
the transmission system or the standards covering the cable plant. ANSWER>>>> - Fiber
type
- Wavelength MM graded index glass fiber optic cables are tested with _____ sources at _____ and _____
wavelengths. ANSWER>>>> - LED
- 850 nm
- 1300 nm SM fiber optic cables are tested with _____ sources at _____ and _____ wavelengths.
ANSWER>>>> - Laser
- 1310 nm
- 1550 nm According to the text, it is recommended that reference test cables be chosen for their _____.
ANSWER>>>> - Low loss
In premises applications, OTDRs are limited in usefulness by their _____. ANSWER>>>> -
Distance resolution
OTDRs are used in outside plant cables to _____, _____, and _____. ANSWER>>>> - Verify
splice loss
- Find faults in installed cables
What does "OTDR" stand for? ANSWER>>>> Optical Time Domain Reflectometer
Which parameters CANNOT be measured by OTDRs in fiber optic networks?
ANSWER>>>> Transmitter and receiver power
The OTDR should never be used without a "launch cable" (aka, "pulse suppressor").
ANSWER>>>> True
Cables tested with an OTDR do not require insertion loss testing with an OLTS.
ANSWER>>>> False
The principle of operation of OTDRs is similar to _____. ANSWER>>>> - Radar
Every network needs lots of _____ which may be directly connected to servers through switches
or connected in a "storage area network" or SAN. ANSWER>>>> - Storage
Wired users and wireless access points are connected to _____ on the network.
ANSWER>>>> - Switches
Which network component switches connections between devices on the network?
ANSWER>>>> Switches
