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Fiber Optics (Light Brigade) Questions
and Answers Rated A+
When was the first North American commercial fiber optic system installed? ✔✔ 1977
What is a mode in an optical fiber? ✔✔Path
What are the "three Cs" of an optical fiber? ✔✔Core, Cladding, Coating
What are the three critical factors to be considered when working with a fiber optic network? ✔✔Attenuation, Dispersion, Reflection
What does the acronym ITU represent? ✔✔International Telecommunication Union
what are the two most commonly used sizes of multimode cores? ✔✔50um, 62.5um
What unit of measurement is used to measure and express wavelengths? ✔✔nm - nanometer
what unit of measurement is used to denote the size of a fiber's core, cladding, and coating? ✔✔um - microns
what are the outside diameters of single-mode and multimode claddings? ✔✔125um
What effects are optical fibers immune to? ✔✔Electrical, Radio
what are the three primary wavelength windows in a fiber optic system? ✔✔850, 1300, 1550
which wavelength has the lowest attenuation? ✔✔ 1550
what part of the electromagnetic spectrum is used by fiber optic systems? ✔✔Infrared
Does light have a higher or lower frequency that radio waves? ✔✔Higher frequency
Does light waves have a longer or shorter wavelength than radio waves? ✔✔Shorter wavelength
what is the bending of light called? ✔✔Refraction
True or False: 80% of the light travels in the core of a single-mode fiber and 20% travels in the inner cladding that is defined as the mode field diameter. ✔✔True
Which type dispersion effect multimode fiber and is direct relation the larger core size? ✔✔Modal dispersion
Which type of dispersion is a combination of material and waveguide dispersion and effects single-mode fiber? ✔✔Chromatic dispersion
What are the most common multimode core diameters? ✔✔50, 62.
What type of fibers are OM1 and OM2 fibers? ✔✔Legacy
What type of fibers are OM3 and OM4 fibers? ✔✔Laser optimized
What are the three functions of the fiber coating? ✔✔Protect, identify, and strength
What is the ITU designation for standard single-mode fiber? ✔✔G.652, G.
What is the ITU designation for single-mode bend-insensitive fiber? ✔✔G.
True or false: Improper bending of an optical fiber will decrease the tensile strength of fibers. ✔✔True
What two types of transmitting light sources can a multimode fiber use? ✔✔LED and VCSEL (laser)
What are the 12 colors identified in the TIA-598 and IEC 60304 color code standards? ✔✔1. Blue, 2. orange, 3. green, 4. brown, 5. 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? ✔✔Infrared
What two wavelengths do multimode fibers most commonly use? ✔✔850, 1300
what two wavelengths do single-mode fibers most commonly use? ✔✔1310, 1550
What are the names of the two types of indoor tight buffered cables? ✔✔Breakout, Distributions
What is a composite cable? ✔✔Fiber and copper
What does the acronym OFNR signify? ✔✔Non-Conductive Riser
What do gels, tapes, and powders in fiber protect against? ✔✔prevent moisture
If a cable has any metallic components at termination point, what does the NEC require? ✔✔grounding IAW NEC 250
What is the NEC 50 foot rule? ✔✔No more than 50 ft inside building
Sequential markings on the outside of cable jackets help to approximate what? ✔✔length
What must installers consider when installing fiber optic cables? ✔✔NEC
What is the dynamic bend radius for fiber optic cable? ✔✔20x outside diameter
What type of cable do central tube and stranded refer to? ✔✔loose tube
What is the maximum pull tension for traditional outside plant cables? ✔✔600lbs
What type of damage was armored cable designed to prevent? ✔✔Rodent and crush protection
What color is used for a UPC single-mode connector? ✔✔Blue
The cladding is bonded to which part of a connector? ✔✔Ferrule
What will a blue UPC or a green APC connector reduce? ✔✔Fresnal Reflection
Per TIA-568, what is the maximum connector insertion loss for use in commercial buildings? ✔✔0.
What is the ITU-T G.671 attenuation value for single-mode connector attenuation? ✔✔0.
What should be done to all connectors prior to plugging them into any components or test equipment? ✔✔Cleaning
What is the maximum splice loss of Telcordia GR-20 and GR-765? ✔✔0.1 dB
What type of reflection does index matching gel reduce? ✔✔Fresnal reflection
How are most single-mode fibers terminated in the field? ✔✔Pigtails
Achieving a good cleave requires the cleaving blade be held at what angle to the fiber? ✔✔perpendicular
What are two types of splice protectors? ✔✔Heat shrink, butterfly
How are most single-mode fibers terminated before they are spliced to the cable's fiber ends? ✔✔Pigtails
True or False: The loss that results from poor polishing, cleaving, or cleaning is classified as extrinsic. ✔✔True
True or False: Mechanical splicing is most common in emergency restoration applications. ✔✔True
True or False: Fusion splicing is the primary solution for single-mode applications. ✔✔True
What are the three types of fusion splicer technologies? ✔✔Profile Alignment System (PAS), Local Inject and Detect (LID), and Fixed V-Groove
What type of deployment has returned fixed V-groove alignment fusion splicers to prominence? ✔✔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. ✔✔True
Great care should be provided when dressing in splice sleeves and fibers to prevent inducing what? ✔✔Micro and macro bending
True or False: Cables should still be able to move freely when secured with tie wraps. ✔✔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. ✔✔True
What must be performed if a cable has metallic elements? ✔✔Grounding
Is strain relief a requirement for fiber and cable management products? ✔✔No requirement
What does "RU" denote? ✔✔Rack Unit
True and False: Installers must consider building codes when installing premises fiber optic cables. ✔✔True
What does the acronym NEC signify? ✔✔National Electrical Code (NEC)
How often is the NEC reissued? ✔✔every 3 years
What is the difference between the terms "dynamic" and "static" in terms of bend radius and tension? ✔✔dynamic - as your doing
static - stored
What is generally accepted dynamic bend radius of fiber optic cable? ✔✔20x outside diameter
Which type of premises cable installation uses compressed air to reduce tension on the cable? ✔✔Air Blown Fiber (ABF)
What is the diameter of the fiber used in an air blown fiber installation? ✔✔250um
What is the role of a Kellems grip? ✔✔Cable attachment device
True or False: Break away swivels will prevent excessive pull tension if the proper rated device is used. ✔✔True
What is the main benefit of a HASB installation? ✔✔Speed and cable strain free
what does the acronym NESC represent? ✔✔National Electric Safety Code (outside)
What information is contained in the NESC? ✔✔Outside plan codes
What does the acronym ADSS stand for? ✔✔All dielectric Self Supporting
What are two very important considerations when installing an aerial fiber optic cable? ✔✔Span length or slag
What is a mid-span entry? ✔✔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. ✔✔True
What is the most common method of installing aerial cables for telephone and CATV organizations? ✔✔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? ✔✔Optical Time-Domain Reflectometer (OTDR)
What is a falt locator used to locate within a fiber optic network? ✔✔Break
Which piece of test equipment uses a red laser light? ✔✔BFL
What types of tests use total fiber distance and decibels per kilometer? ✔✔Acceptance Test
What is a simple device used to locate faults in the OTDR deadzone? ✔✔VFL
What instrument is used to visually inspect fiber optic connector endfaces? ✔✔Inspection scope
What function does a fiber identifier serve? ✔✔Tones/Locate light fiber
Are fiber identifiers effective with multimode fiber? ✔✔no
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. ✔✔True
How will a mechanical splice or a connector show up on the OTDR display? ✔✔Fresnal Reflection Spike
What type of OTDR measurements require the correct fiber index of refraction value? ✔✔Length
True or False: The OTDR measures cable length. ✔✔False
What is the difference between optical return loss (ORL) and reflectance? ✔✔Reflectance - 1 point in a system
ORL - Total reflectance
What type of test equipment can measure both ORL and reflectance? ✔✔OTDR
What is the only thing a continuity tester tests for in the optical fibers? ✔✔Break
What are the different launch conditions and methods used to perform multimode attenuation tests? ✔✔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. ✔✔False - Range, Pulse Width, index of Refraction, Wavelength
What is a deadzone? ✔✔The area where we can't make measurements, blind spots
How can attenuation and reflection measurements be made with a OTDR? ✔✔Averaging mode
True or False: Optical loss test sets are the only test equipment that truly measures end-to-end loss. ✔✔True
Which laser classification designates a retina-safe laser? ✔✔Class 1
