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FIBER OPTICS (LIGHT
BRIGADE) EXAM
True or False: "Not to exceed" charts help to quickly determine if the total loss of span meets the required end-to-end loss specifications and individual component values. - ANSWERS-True How will a mechanical splice or a connector show up on the OTDR display? - ANSWERS-Fresnal Reflection Spike What type of OTDR measurements require the correct fiber index of refraction value? - ANSWERS-Length True or False: The OTDR measures cable length. - ANSWERS-False What is the difference between optical return loss (ORL) and reflectance? - ANSWERS-Reflectance - 1 point in a system ORL - Total reflectance What type of test equipment can measure both ORL and reflectance? - ANSWERS-OTDR What is the only thing a continuity tester tests for in the optical fibers?
What are the different launch conditions and methods used to perform multimode attenuation tests? - ANSWERS-Overfill, Restricted, Encircle Flux, Mode Conditioning patch cord. True or False: The five common settings on an OTDR that should be set up properly are range, average time, pulse width, index of refraction, and proper marker placement. - ANSWERS-False - Range, Pulse Width, index of Refraction, Wavelength What is a deadzone? - ANSWERS-The area where we can't make measurements, blind spots How can attenuation and reflection measurements be made with a OTDR? - ANSWERS-Averaging mode True or False: Optical loss test sets are the only test equipment that truly measures end-to-end loss. - ANSWERS-True Which laser classification designates a retina-safe laser? - ANSWERS-Class 1 True or False: Shorter wavelengths are more dangerous at lower power levels. - ANSWERS-True What safety forms must be available for review when working with chemicals? - ANSWERS-Material Safety Data Sheet (MSDS)
what are the two most commonly used sizes of multimode cores? - ANSWERS-50um, 62.5um What unit of measurement is used to measure and express wavelengths? - ANSWERS-nm - nanometer what unit of measurement is used to denote the size of a fiber's core, cladding, and coating? - ANSWERS-um - microns what are the outside diameters of single-mode and multimode claddings? - ANSWERS-125um What effects are optical fibers immune to? - ANSWERS-Electrical, Radio what are the three primary wavelength windows in a fiber optic system? - ANSWERS-850, 1300, 1550 which wavelength has the lowest attenuation? - ANSWERS- 1550 what part of the electromagnetic spectrum is used by fiber optic systems? - ANSWERS-Infrared Does light have a higher or lower frequency that radio waves? - ANSWERS-Higher frequency
Does light waves have a longer or shorter wavelength than radio waves? - ANSWERS-Shorter wavelength what is the bending of light called? - ANSWERS-Refraction what type of reflection is caused by an air gap in a connector pair? - ANSWERS-Fresnel reflection what are the three ways to reduce modal dispersion in a multimode system? - ANSWERS-graded index fiber, smaller core, longer wavelength True or False: All wavelengths travel at the same speed through the fiber. - ANSWERS-False What are the two most common multimode wavelengths? - ANSWERS-850, 1300 What type of loss will a poor cleave angle cause: intrinsic or extrinsic? - ANSWERS-Extrinsic The acronym IOR is the ratio of speed of light in a vacuum versus the speed of light in what? - ANSWERS-Glass
What is the ITU designation for standard single-mode fiber? - ANSWERS-G.652, G. What is the ITU designation for single-mode bend-insensitive fiber? - ANSWERS-G. True or false: Improper bending of an optical fiber will decrease the tensile strength of fibers. - ANSWERS-True What two types of transmitting light sources can a multimode fiber use? - ANSWERS-LED and VCSEL (laser) What are the 12 colors identified in the TIA- 598 and IEC 60304 color code standards? - ANSWERS-1. Blue, 2. orange, 3. green, 4. brown,
- slate, 6. white, 7. red, 8. black, 9. yellow, 10. violet, 11. rose, 12. aqua In what spectrum of light do the fiber optic wavelengths take place? - ANSWERS-Infrared What two wavelengths do multimode fibers most commonly use? - ANSWERS-850, 1300 what two wavelengths do single-mode fibers most commonly use? - ANSWERS-1310, 1550
True and false: Different wavelengths travel at different speeds through a fiber. - ANSWERS-True What will happen to the number of modes as the wavelength decreases? - ANSWERS-More modes True or false: ITU-T G.652D is classified as low water peak or zero water peak single-mode fiber. - ANSWERS-True True or false: ITU-T G.55 is single-mode fiber that was optimized for 1550 - nm transmissions. - ANSWERS-True What colors are used for single-mode cordage? What about for mulimode cordage? - ANSWERS-single-mode: yellow multimode: orange What is the outside coating diameter of the fiber in tightbuffered cables? - ANSWERS-900um What is the outside coating diameter of the fiber in loose buffered cables? - ANSWERS-250um What are the names of the two types of indoor tight buffered cables? - ANSWERS-Breakout, Distributions What is a composite cable? - ANSWERS-Fiber and copper
What is the maximum pull tension for traditional outside plant cables?
- ANSWERS-600lbs What type of damage was armored cable designed to prevent? - ANSWERS-Rodent and crush protection What color is used for a UPC single-mode connector? - ANSWERS- Blue The cladding is bonded to which part of a connector? - ANSWERS- Ferrule What will a blue UPC or a green APC connector reduce? - ANSWERS-Fresnal Reflection Per TIA-568, what is the maximum connector insertion loss for use in commercial buildings? - ANSWERS-0. What is the ITU-T G.671 attenuation value for single-mode connector attenuation? - ANSWERS-0. What pattern should be used when hand polishing a multimode connector? - ANSWERS-Figure 8 What other name are MPO and MTP connectors also known by? - ANSWERS-Array Connector
From what material are most precision ferrules made? - ANSWERS- Ceramic What is the ferrule diameter of most small form factor connectors? - ANSWERS-1.25mm What are four desirable factors to look for in a connector? - ANSWERS-low loss, mechanical protection, low reflectance, repeatability Hardened connectors are typically used in what type of application? - ANSWERS-FTTX Fiber-to-the-X (house) Where are minor defects allowed on the surface of the ferrule? - ANSWERS-Outer cladding What should be done to all connectors prior to plugging them into any components or test equipment? - ANSWERS-Cleaning What is the maximum splice loss of Telcordia GR- 20 and GR-765? - ANSWERS-0.1 dB What type of reflection does index matching gel reduce? - ANSWERS-Fresnal reflection
What type of deployment has returned fixed V-groove alignment fusion splicers to prominence? - ANSWERS-FTTX Fiber-to-the- Home True or False: Arc temperature or burn-back test should be conducted as needed, but specifically any time there is a humidity or altitude change. - ANSWERS-True Great care should be provided when dressing in splice sleeves and fibers to prevent inducing what? - ANSWERS-Micro and macro bending What type of panel can be used as a central access location for testing and troubleshooting? - ANSWERS-Patch panel What does a fanout kit do? - ANSWERS-convert 250um to 900um What standards are used for premise installations of cable management products? - ANSWERS-TIA 568, 569, IAC 11801 What cable management product has both splicing and connector functions? - ANSWERS-Distribution panel What do break out kids do? - ANSWERS-builds 250um into cordage What does a splice closure do? - ANSWERS-encloses the splices
True or False: the damage that tight tie wraps can cause is not limited to breakage, most often it causes a significant reduction signal, requiring unnecessary troubleshooting and network downtime. - ANSWERS-True True or False: Cables should still be able to move freely when secured with tie wraps. - ANSWERS-True True or False: When dressing in fibers into patch panels, it's very important not to leave any fibers outside of the internal cable management, as micro-bends can occur when fibers are compressed or pinched by panel doors, latches, or other hardware. - ANSWERS- True What must be performed if a cable has metallic elements? - ANSWERS-Grounding Is strain relief a requirement for fiber and cable management products? - ANSWERS-No requirement What does "RU" denote? - ANSWERS-Rack Unit True and False: Installers must consider building codes when installing premises fiber optic cables. - ANSWERS-True
True or False: Utilization of duct plugs will prevent not only moisture but also blockage. - ANSWERS-True What do the sequential markings help the cable installer to determine?
- ANSWERS-Total length of cable What should a cable installer be aware of when installing fiber optic cables into a conduit? - ANSWERS-Fill ratio What is the maximum fill percentage ration by cross-sectional area for a conduit with one cable? - ANSWERS-53% What is recommended to have for future changes and restorations? - ANSWERS-Slack (service loops) What are three primary methods for underground installation of fiber optic cable? - ANSWERS-Trench, Plow, Bore What does the acronym HASB signify? - ANSWERS-High Air Speed Blown What is the main benefit of a HASB installation? - ANSWERS-Speed and cable strain free what does the acronym NESC represent? - ANSWERS-National Electric Safety Code (outside)
What information is contained in the NESC? - ANSWERS-Outside plan codes What does the acronym ADSS stand for? - ANSWERS-All dielectric Self Supporting What are two very important considerations when installing an aerial fiber optic cable? - ANSWERS-Span length or slag What is a mid-span entry? - ANSWERS-Entry in the middle (access cable without cutting) True or False: Maxcell bags were designed not only to separate and maximize duct space but also to decrease cable friction. - ANSWERS- True What is the most common method of installing aerial cables for telephone and CATV organizations? - ANSWERS-Lashing/Overlash What type of test equipment is used to test for total distance and provide attenuation values for fiber loss per kilometer, splice, connector, and total span loss? - ANSWERS-Optical Time-Domain Reflectometer (OTDR) What is a falt locator used to locate within a fiber optic network? - ANSWERS-Break
What two wavelengths are used when measuring single-mode fiber spans? - ANSWERS-1310, 1550 What fiber optic test equipment is required for calibration traceable to the National Institute of Standards Technology? - ANSWERS-Power meter What should be done to all connectors before testing? - ANSWERS- Cleaning What type of light sources are used to test LANs for OM1 and OM fibers? - ANSWERS-LED What type of light sources are used to test LANs for OM3 and OM fibers? - ANSWERS-LED Mandrel or VCSEL
