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JATC FIBER OPTICS FINAL
OTDRs are used in outside plant cables to , , and. - ANSWERS-- Verify splice loss
- Measure length
- Find faults in installed cables What does "OTDR" stand for? - ANSWERS-Optical Time Domain Reflectometer Which parameters CANNOT be measured by OTDRs in fiber optic networks? - ANSWERS-Transmitter and receiver power The OTDR should never be used without a "launch cable" (aka, "pulse suppressor"). - ANSWERS-True Cables tested with an OTDR do not require insertion loss testing with an OLTS. - ANSWERS-False The principle of operation of OTDRs is similar to. - ANSWERS-- Radar Every network needs lots of which may be directly connected to servers through switches or connected in a "storage area network" or SAN. - ANSWERS-- Storage
Wired users and wireless access points are connected to on the network. - ANSWERS-- Switches Which network component switches connections between devices on the network? - ANSWERS-Switches What type of network architecture consists of all network devices/users connected to a central point that switches or connects them to whomever they want to communicate with? - ANSWERS- Star topology What type of network architecture utilizes connections that "tap" into a cable that is usually coax? - ANSWERS-Bus topology The Internet is an example of what type of network architecture? - ANSWERS-Mesh topology Telephone systems and LAN's commonly use networks. - ANSWERS-- Star The essence of any network is that the network shares connections and thereby shares the available. - ANSWERS-- Bandwidth What network device replaced a hub, making full duplex data transfer possible? - ANSWERS-Switches
An advantage of optical fiber is the fact that it is the most cost effective means of transporting information over long distances. - ANSWERS-True The bandwidth and distance capability of optical fiber means that
. - ANSWERS-- 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. - ANSWERS-Eye protection Information on the safety of chemicals used in fiber optics are.
- ANSWERS-In MSDS supplied by the manufacturer. Inspection microscopes can concentrate the light from a fiber into your eye causing serious damage. - ANSWERS-True Bright red visible light is produced by a VFL that is safe to look at directly at the end of the fiber. - ANSWERS-False A digital camera can see infrared light, so it can be used to determine if there is light present in a fiber. - ANSWERS-True
Dangerous light from fiber optic cables is bright and easily visible. - ANSWERS-False During fiber optic installations, the most common danger is caused by
. - ANSWERS-Fiber scraps or shards by cleaving, splicing, and termination. If you inspect a fiber optic connector that is connected to a laser source with a microscope, you will experience a high level of pain while your eye is damaged. - ANSWERS-False What are some potential hazards associated with the use of cleaning solvents that are sometimes used when working with fiber optics? - ANSWERS-- Vapors
- Skin irritation To ensure that you are using proper protective eyewear, look for the mark on your glasses. - ANSWERS-- ANSI Z Proper eyewear should include for maximum protection from flying debris. - ANSWERS-- Side shields SM fiber has a light-carrying core than multimode (MM) fiber.
- ANSWERS-- Smaller What is the core size of SM fiber? - ANSWERS- 9 microns
"Thin strands of highly transparent glass or plastic that guide light" defines. - ANSWERS-- Optical fiber The term "nanometer" is a measurement that is often used in fiber optics to express. - ANSWERS-Wavelengths of light The diameter of an optical fiber is traditionally measured in /. - ANSWERS-- Microns/micrometers Multimode fiber systems operation at speeds of 1 gigabit per second or more for short lengths use. - ANSWERS-- Vertical cavity surface emitting lasers (VCSELs) LED light sources have a very spectra, while laser light sources have a very spectra. - ANSWERS-- Broad
- Narrow What wavelengths would an F-P laser light source used for SM operate at for transmission over fiber optic cabling? - ANSWERS- 1300 and 1550 nm What wavelengths are appropriate for use with MM fiber? - ANSWERS-850 and 1300 nm
What wavelengths are appropriate for use with SM fiber? - ANSWERS-1310 and 1550 nm Light-emitting diodes (LEDs) have higher output power and bandwidth than lasers. - ANSWERS-False An F-P laser light source emits its light from the of the microchip. - ANSWERS-- Side The light source best matched for a multimode fiber link operating at less than 100MB/s would be an. - ANSWERS-- LED Loss of a fiber or any fiber in a cable is measured in. - ANSWERS-- dB In multimode fiber, the attenuation of the fiber is at 850 nm than at 1300nm. - ANSWERS-- Higher "The reduction in optical power as it passes along a fiber" is known as
. - ANSWERS-- Attenuation Scattering quickly at longer wavelengths. - ANSWERS-- Decreases The largest contributor to fiber attenuation is. - ANSWERS-- Scattering
What is caused by varying speeds in each mode in multimode fiber? - ANSWERS-- Modal dispersion Fiber bandwidth is limited by. - ANSWERS-- Dispersion The proper method of pulling optical fiber cables is to attach the pull wire or tape to the of the cable. - ANSWERS-- 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? - ANSWERS-- Distribution tight buffer cable What absorbs the tension needed to pull fiber optic cable and provides cushioning for the fibers? - ANSWERS-Aramid yarn strength members What provides additional protection to the fiber and allows for easier handling and direct termination to the fiber? - ANSWERS- 900 micron tight buffer coating The first layer of protection of a fiber optic cable is the. - ANSWERS-250 micron primary buffer coating Which of the following cables would be used for patch cord and backplane applications? - ANSWERS-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? - ANSWERS-Break-out cable What type of cable may require installation of a breakout kit (also called a furcation or fan out kit) for termination? - ANSWERS-Loose tube cable What type of cable withstands crush loads well, protects against rodents, and can be directly buried? - ANSWERS-Armored cable What type of cable is most widely used for outside plant (OSP) trunks because it offers the best protection for the fibers under high pulling tensions and can be easily protected from moisture with water- blocking gel or tapes? - ANSWERS-Loose tube cable In a loose tube cable, a gel or absorbent tape or powder is normally used. - ANSWERS-- To prevent water from entering the cable Fiber optic cable for use inside a building must be. - ANSWERS-- Rated to meet the requirements of local building and fire codes What type of fiber cable design allows for large numbers of fibers with ultra-high density, small size (diameter) and low cost? - ANSWERS-Ribbon cable
The connector with the best or lowest reflectance would be the.
- ANSWERS-- SC-APC What connector color is typically used to identify multimode? - ANSWERS-Beige What connector color is typically used to identify singlemode? - ANSWERS-Blue Fiber optic joints (connectors or splices) should have , , and. - ANSWERS-- Low loss
- Minimal reflectance
- High mechanical strength Physical contact (PC) polish on connectors is designed to reduce . - ANSWERS-- Loss and reflectance When terminating fiber, what is used to precisely "break" the fiber to produce a flat end for polishing or splicing? - ANSWERS-Cleaver When preparing a fiber for termination, what is stripped off of the fiber before placing it within a connector? - ANSWERS-Primary buffer coating A is a hard, sharp tool that scratches the fiber to allow cleaving.
- ANSWERS-- Scribe
Before terminating a fiber optic connector, make sure to slide the onto the cable. - ANSWERS-- Boot When injecting epoxy into a connector, how do you know when you have injected enough? - ANSWERS-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? - ANSWERS-"Air polish" to grind down the cleaved fiber What should you reference in order to strip the fiber, buffer, and strength members to the right length? - ANSWERS-Manufacturer's packaging instructions What is needed to get low loss from pre polished splice connector? - ANSWERS-Good initial cleave The manufacturing process of pre-polished connectors is complex and requires extra care, so these connectors are as much as 10 times the amount of an adhesive-and-polish type. - ANSWERS-True What type of splice uses an electric arc to splice two fibers together? - ANSWERS-Fusion splice
What can be used to optimize a mechanical splice for low loss? - ANSWERS-Visual Fault Locator The link loss budget analysis of a cable plant should be done to , , and. - ANSWERS-- 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. - ANSWERS-- Electrical
- Optical The amount of optical power lost as light is transmitted through fiber, splices, and couplers is defined as. - ANSWERS-- Optical loss Connectors at each end of the cable plant should not be counted when calculating the cable plant loss. - ANSWERS-False What component can convert an electrical signal to or from an optical signal? - ANSWERS-Tranceiver Fiber optic links generally use two fibers for full duplex (bidirectional) links. - ANSWERS-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. - ANSWERS-True A visible light source (LED or flashlight) used to visually check fiber continuity and location of faults is called a. - ANSWERS-- Fiber tracer What is used to inspect the end surface of a connector for faults such as scratches, polish, or dirt? - ANSWERS-Inspection microscope What fiber optic test simulates actual system operation? - ANSWERS-Optical Loss Test Set (OLTS) What test instrument(s) are used for insertion loss testing? - ANSWERS-OLTS or power meter and light source Inspection of fibers with an Interferometer is a common field test of fiber optics that is done before plugging into equipment. - ANSWERS-False Connector "dust caps" can transfer dirt onto a fiber optic connector. - ANSWERS-True The infrared light coming out of a fiber optic cable is invisible, but if you look at it through a cell phone camera it is visible. - ANSWERS- True
SM fiber optic cables are tested with sources at and wavelengths. - ANSWERS-- Laser
- 1310 nm
- 1550 nm According to the text, it is recommended that reference test cables be chosen for their. - ANSWERS-- Low loss In premises applications, OTDRs are limited in usefulness by their . - ANSWERS-- Distance resolution
