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FOA CFOS/H practice questions

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Question 1Fiber optics fundamentals and home fiber architectures

In a typical FTTH installation, what is the primary function of the optical network terminal (ONT) at the subscriber's premises?

  1. It splits one feeder fiber into multiple drop fibers toward neighboring homes
  2. It provides the central office with power metering for the subscriber line
  3. It converts the incoming optical signal into electrical Ethernet and voice services for the home Correct answer.
  4. It amplifies the optical signal before it reaches the splitter

Explanation

The ONT terminates the drop fiber at the customer site and performs optical-to-electrical conversion so that standard in-home equipment (routers, phones, set-top boxes) can use the service. It is the subscriber-side endpoint of the PON. Splitting and amplification happen elsewhere in the network, not inside the ONT.

Question 2Fiber optics fundamentals and home fiber architectures

Which wavelength window is most commonly used for the downstream signal in a GPON access network?

  1. 1310 nm
  2. 1625 nm
  3. 1490 nm Correct answer.
  4. 850 nm

Explanation

GPON uses 1490 nm for downstream traffic and 1310 nm for upstream traffic, keeping the two directions separated by wavelength. The 1550 nm region is reserved for video overlay, and 1625 nm is often used for monitoring. The 850 nm window is typical of short-reach multimode datacom links, not PON access.

Question 3Fiber optics fundamentals and home fiber architectures

What is the main reason single-mode fiber is preferred over multimode fiber for long-reach home broadband access networks?

  1. It has a larger core diameter that captures more light
  2. It supports only short wavelengths, which reduces attenuation
  3. It eliminates modal dispersion, allowing much greater transmission distance Correct answer.
  4. It is cheaper to terminate in the field than multimode fiber

Explanation

Single-mode fiber has a small core that supports essentially one propagation path, so modal dispersion is negligible and signals travel far greater distances. Multimode fiber suffers modal dispersion that limits reach. This is the key reason access networks standardize on single-mode fiber.

Question 4Fiber optics fundamentals and home fiber architectures

A technician reads a loss of 0.35 dB/km at 1310 nm on a newly installed single-mode drop cable. Which statement best interprets this result?

  1. The reading is consistent with normal single-mode attenuation at that wavelength Correct answer.
  2. The reading indicates a macrobend that must be repaired
  3. The reading proves the fiber is multimode rather than single-mode
  4. The fiber is defective because 1310 nm loss should be below 0.1 dB/km

Explanation

Standard single-mode fiber has attenuation near 0.35 dB/km at 1310 nm, so this measurement is within normal expectations. Loss at 1550 nm is lower, around 0.2 dB/km, but 1310 nm values near 0.35 dB/km are typical. Nothing in the reading alone suggests a fault.

Question 5Fiber optics fundamentals and home fiber architectures

In a passive optical network, what does a 1:32 splitter do to the downstream optical signal?

  1. It divides the optical power among 32 outputs, introducing an insertion loss of roughly 15 dB Correct answer.
  2. It blocks downstream traffic and passes only upstream traffic
  3. It combines 32 upstream signals into a single wavelength-converted stream
  4. It regenerates the signal at full power on each of the 32 outputs

Explanation

A passive splitter divides incoming optical power among its output ports, so each port receives a fraction of the original power. A 1:32 split corresponds to about 15 dB of theoretical splitting loss, plus excess loss. Splitters are passive and do not regenerate or wavelength-convert signals.

Question 6Fiber optics fundamentals and home fiber architectures

Which connector polish type is designed to reduce back-reflection by bringing the fiber cores into physical contact?

  1. PC (physical contact) Correct answer.
  2. SC duplex
  3. ST bayonet
  4. LC unibody

Explanation

Physical contact (PC) polishing curves the ferrule endface so that the fiber cores touch directly, minimizing the air gap and reducing back-reflection. APC goes further with an angled polish for even lower reflectance. ST, SC, and LC describe connector form factors rather than the polish that controls reflection.

Question 7Fiber optics fundamentals and home fiber architectures

A home is served by an FTTH drop cable that enters through an exterior wall. Which practice best protects the indoor fiber from bend-induced loss?

  1. Staple the cable firmly against the wall at short intervals
  2. Terminate the drop directly onto a bare fiber adapter without a patch panel
  3. Maintain a minimum bend radius and secure the cable with loose cable ties Correct answer.
  4. Coil excess fiber tightly around a small radius to save space

Explanation

Respecting the fiber's minimum bend radius prevents macrobending loss and mechanical damage, and loose ties avoid pinching. Tight coiling and stapling create small-radius bends that leak light. A proper enclosure or patch panel also protects the termination.

Question 8Fiber optics fundamentals and home fiber architectures

What is the purpose of an APC (angled physical contact) connector in a home fiber installation?

  1. To allow the connector to be cleaned without removing it
  2. To increase the core diameter for easier alignment
  3. To reduce back-reflection to below that of a standard PC connector Correct answer.
  4. To permit both single-mode and multimode use on the same ferrule

Explanation

The 8-degree angled endface of an APC connector directs reflected light into the cladding rather than back down the fiber, achieving lower reflectance than PC. This is valuable in PON and video overlay systems where reflections matter. APC does not change core size or cleaning requirements.

Question 9Fiber optics fundamentals and home fiber architectures

During a fusion splice of two single-mode fibers, the technician sees a large estimated loss on the splicer display. Which action is most appropriate?

  1. Increase the arc power and duration without re-cleaving
  2. Cleave both fibers again and repeat the splice Correct answer.
  3. Accept the splice because splicer estimates are always inaccurate
  4. Wrap the splice in tape and proceed to the next location

Explanation

A high estimated loss usually indicates a poor cleave angle, contamination, or misalignment, and the reliable fix is to re-cleave and re-splice. Repeating with fresh cleaves addresses the root cause. Accepting or taping over a bad splice leaves a permanent high-loss point.

Question 10Fiber optics fundamentals and home fiber architectures

Which fiber type is specified by ITU-T G.657 and is commonly deployed for in-home wiring because of its improved bend tolerance?

  1. Standard single-mode fiber
  2. OM3 multimode fiber
  3. Bend-insensitive single-mode fiber Correct answer.
  4. OM4 multimode fiber

Explanation

G.657 defines bend-insensitive single-mode fiber that tolerates tighter bends than standard G.652 fiber, which suits cramped indoor routing. OM3 and OM4 are multimode grades used in short-reach data links. Standard single-mode is G.652.

Question 11Fiber optics fundamentals and home fiber architectures

A passive optical splitter with a 1:8 ratio is cascaded with a 1:4 splitter. What is the total split ratio reaching the subscriber ports?

  1. 1:32 Correct answer.
  2. 1:64
  3. 1:12
  4. 1:16

Explanation

Cascaded splitters multiply their ratios, so 1:8 followed by 1:4 yields 1:32. The combined splitting loss is the sum of the individual losses, roughly 9 dB plus 6 dB. Adding the ratios (1:12) is a common but incorrect shortcut.

Question 12Fiber optics fundamentals and home fiber architectures

What does the term 'feeder fiber' refer to in an FTTH network architecture?

  1. The short fiber inside the ONT connecting the transceiver to the port
  2. The fiber running from the central office or OLT to the first splitter point Correct answer.
  3. The patch cord used to connect test equipment to a fiber adapter
  4. The drop cable from the splitter to an individual home

Explanation

In PON terminology the feeder fiber carries traffic from the OLT at the central office to the distribution point where splitting begins. The distribution fiber runs between splitters, and the drop fiber reaches the subscriber. Patch cords and internal pigtails are not called feeder fiber.

Question 13Fiber optics fundamentals and home fiber architectures

Which measurement technique is used to locate a high-loss event along a deployed fiber by analyzing backscattered light versus distance?

  1. Optical time-domain reflectometry Correct answer.
  2. Visual fault location with a red laser
  3. Optical power metering
  4. Insertion loss testing with a light source

Explanation

An OTDR sends pulses and measures backscattered and reflected light over time, converting delay into distance so events can be located. Power meters and loss test sets give total loss but not location. A visual fault locator only shows a glow at a nearby break.

Question 14Fiber optics fundamentals and home fiber architectures

An installer must verify that a completed drop cable meets a specified end-to-end loss budget. Which test setup is appropriate?

  1. A visual fault locator observed at the far end
  2. A fiber cleaver and a microscope
  3. An OTDR with a very short pulse width connected to one end only
  4. A light source and power meter referenced to a known launch power Correct answer.

Explanation

Insertion loss is measured with a stabilized light source and an optical power meter, with the meter referenced to the source output before the fiber under test is inserted. This gives the end-to-end loss for comparison with the budget. OTDRs measure events but require care for absolute loss, and a VFL does not quantify loss.

Question 15Fiber optics fundamentals and home fiber architectures

Why must a reference test jumper be used when performing an insertion loss measurement with a light source and power meter?

  1. To convert the multimode signal into single-mode
  2. To establish a known reference power level so connector and launch losses are excluded Correct answer.
  3. To verify that the fiber under test is not bent
  4. To increase the output power of the light source

Explanation

Referencing sets the meter to the source power as delivered through a known jumper, so the measured loss reflects only the fiber under test and its terminations. Without referencing, launch and connector losses would be included incorrectly. The jumper does not change source power or fiber type.

Question 16Fiber optics fundamentals and home fiber architectures

In a GPON system, which direction of transmission uses the 1310 nm wavelength?

  1. Video overlay from the headend
  2. RF return path from the set-top box
  3. Upstream from ONT to OLT Correct answer.
  4. Downstream from OLT to ONT

Explanation

GPON assigns 1310 nm to the upstream direction from the ONT to the OLT and 1490 nm to the downstream direction. Video overlay typically uses 1550 nm. RF return paths are electrical, not optical at 1310 nm.

Question 17Fiber optics fundamentals and home fiber architectures

A technician is asked to identify the type of fiber that uses a 50-micron core and is graded for high-bandwidth short-reach links in a home media network. Which designation applies?

  1. OM3 Correct answer.
  2. G.657.A1
  3. OS2
  4. G.652.D

Explanation

OM3 is a laser-optimized 50-micron multimode fiber rated for high-bandwidth short-reach links such as 10G Ethernet in a home or small office. OS2, G.652, and G.657 are all single-mode designations with much smaller cores. The 50-micron core is the defining clue for multimode.

Question 18Fiber optics fundamentals and home fiber architectures

What is the primary reason an FTTH provider records a loss budget for each PON branch?

  1. To determine the color code of the drop cable jacket
  2. To set the upstream laser wavelength
  3. To calculate the electrical power consumed by the ONT
  4. To ensure the total loss stays within the optical transceiver's operating range Correct answer.

Explanation

A loss budget sums fiber, splice, connector, and splitter losses so the design stays within the transceiver's dynamic range. If loss is too high, the receiver may not detect the signal; if too low, the receiver may be overloaded. Jacket color and wavelength selection are unrelated to the budget.

Question 19Fiber optics fundamentals and home fiber architectures

Which condition is most likely to cause increased attenuation at 1550 nm while leaving 1310 nm loss nearly unchanged?

  1. A poor fusion splice
  2. A mismatched core diameter
  3. A tight bend in the fiber Correct answer.
  4. A dirty connector endface

Explanation

Macrobending loss is strongly wavelength-dependent, becoming pronounced at longer wavelengths such as 1550 nm while 1310 nm is less affected. Dirty connectors, bad splices, and core mismatch tend to raise loss at both wavelengths. This wavelength dependence is a useful diagnostic signature.

Question 20Fiber optics fundamentals and home fiber architectures

An OTDR trace of a home drop shows a reflective spike followed immediately by a drop in the backscatter level, then a gradual rise. What does the event most likely represent?

  1. A gradual macrobend along the cable
  2. A fusion splice with low loss
  3. The end of the fiber under test
  4. A connector pair with a small air gap Correct answer.

Explanation

A reflective spike indicates a discrete reflection, typical of a connector or air gap, and the subsequent drop in backscatter indicates loss at that point. A fusion splice normally shows loss without a strong reflection. A macrobend appears as a gradual loss region, and the fiber end shows a large terminal reflection.

Question 21Fiber optics fundamentals and home fiber architectures

A home network uses a passive optical LAN with a 1:16 splitter and a total fiber loss of 3 dB before the splitter. If the OLT launch power is +2 dBm and the splitter loss is 12 dB, what is the approximate power reaching each ONT, ignoring connector and splice losses?

  1. +14 dBm
  2. -2 dBm
  3. -10 dBm
  4. -13 dBm Correct answer.

Explanation

Subtract the fiber loss and splitter loss from the launch power: +2 dBm minus 3 dB minus 12 dB equals -13 dBm. Losses in decibels are subtracted directly from the power level. Adding losses or ignoring the fiber segment gives incorrect results.

Question 22Fiber optics fundamentals and home fiber architectures

Which statement correctly describes the role of the optical line terminal (OLT) in an FTTH network?

  1. It terminates the PON at the central office and manages traffic to many ONTs Correct answer.
  2. It converts optical signals into Wi-Fi inside the subscriber's home
  3. It provides the mechanical splice between distribution and drop cables
  4. It measures the loss of each drop cable during installation

Explanation

The OLT is the central-office endpoint of the PON, aggregating and managing traffic for many subscriber ONTs. Wi-Fi conversion happens in the home gateway, and splices are passive field components. Loss measurement is a test function, not an OLT role.

Question 23Fiber optics fundamentals and home fiber architectures

What is the function of a fiber pigtail in a home fiber termination box?

  1. It is a device that converts optical signals to electrical signals
  2. It is a tool used to cleave fiber before splicing
  3. It is a protective sleeve placed over a bare fiber splice
  4. It is a short fiber with a factory connector on one end, spliced to the field fiber Correct answer.

Explanation

A pigtail is a short length of fiber with a factory-terminated connector on one end and a bare end for splicing to the field fiber. This provides a reliable, low-loss connector without field polishing. Cleavers, splice protectors, and media converters are different items.

Question 24Fiber optics fundamentals and home fiber architectures

A technician must route a drop cable through a tight corner in a home. Which approach best preserves optical performance?

  1. Cut and splice the cable at the corner to eliminate the bend
  2. Bend the cable sharply because single-mode fiber is unaffected by bends
  3. Use a bend-radius guide or slack loop to keep the bend above the cable's minimum radius Correct answer.
  4. Pull the cable as tightly as possible to keep it out of the way

Explanation

Using a bend-radius guide or slack loop keeps the bend within the cable's rated minimum radius, preventing macrobend loss and damage. Tight pulling and sharp bends stress the fiber, and unnecessary splices add loss and failure points. Even bend-insensitive fiber has limits.

Question 25Fiber optics fundamentals and home fiber architectures

Which factor most directly determines the maximum number of subscribers that can share a single PON port?

  1. The jacket color of the drop cable
  2. The number of Ethernet ports on the ONT
  3. The length of the patch cord at the OLT
  4. The split ratio and the resulting loss budget Correct answer.

Explanation

The split ratio sets how many subscribers share a PON port, but it also increases splitting loss, so the design must stay within the loss budget and transceiver range. Jacket color, patch cord length at the OLT, and ONT Ethernet port count do not set the subscriber limit. Splitting and budget are evaluated together.

Question 26Fiber optics fundamentals and home fiber architectures

In a home fiber installation, which unit is conventionally used to express optical return loss (ORL) at a connector interface?

  1. Decibels (dB) Correct answer.
  2. Milliwatts (mW)
  3. Decibels relative to one milliwatt (dBm)
  4. Nanometers (nm)

Explanation

Optical return loss is a ratio of reflected power to incident power, so it is expressed in decibels as a positive magnitude. dBm would describe an absolute power level, not a ratio, and nanometers describe wavelength rather than loss.

Question 27Fiber optics fundamentals and home fiber architectures

A single-mode fiber is described as having a mode field diameter of about 9.2 µm at 1310 nm. What does this value represent?

  1. The effective width of the optical power distribution in the core Correct answer.
  2. The diameter of the protective buffer coating
  3. The maximum bend radius permitted before breakage
  4. The physical diameter of the glass cladding

Explanation

Mode field diameter describes how widely the guided optical power is distributed across the core and slightly into the cladding, and it is always somewhat larger than the physical core. It is used to estimate splice loss between dissimilar fibers rather than to describe cladding or coating dimensions.

Question 28Fiber optics fundamentals and home fiber architectures

Which wavelength window is conventionally used for the upstream direction in a GPON FTTH access network?

  1. 1310 nm Correct answer.
  2. 1550 nm
  3. 1625 nm
  4. 1490 nm

Explanation

GPON assigns 1310 nm to the upstream burst transmission from ONTs to the OLT and 1490 nm to the downstream continuous signal. The 1550 nm window is reserved for optional RF video overlay, and 1625 nm is used for maintenance and in-service testing.

Question 29Fiber optics fundamentals and home fiber architectures

What is the primary function of an optical network terminal (ONT) in a home FTTH deployment?

  1. It terminates the PON at the customer premises and converts optical signals to electrical service interfaces Correct answer.
  2. It provides the upstream laser source for all subscribers on the PON
  3. It splits one downstream signal among several subscriber drops
  4. It amplifies the optical signal before it reaches the subscriber

Explanation

The ONT sits at the subscriber end of the PON and converts the optical signal into the electrical interfaces the home uses, such as Ethernet, voice, or video. It also contains the burst-mode upstream transmitter for that individual subscriber.

Question 30Fiber optics fundamentals and home fiber architectures

A technician measures a PON branch and finds 21.5 dB of total loss, while the design budget allows 28 dB. Which conclusion is correct?

  1. The branch is within budget with margin remaining Correct answer.
  2. The branch is acceptable only if the splitter ratio is changed
  3. The branch exceeds the budget and must be reworked
  4. The branch is invalid because loss budgets must be whole numbers

Explanation

The measured loss of 21.5 dB is below the 28 dB allowance, so the branch has 6.5 dB of headroom and passes the design check. Loss budgets are compared as numeric values, and fractional decibels are entirely normal in measurement.

Question 31Fiber optics fundamentals and home fiber architectures

A 1:32 splitter is replaced with a 1:16 splitter on the same PON branch. What happens to the theoretical splitting loss?

  1. It stays the same because splitting loss depends only on fiber length
  2. It decreases by about 10 dB
  3. It decreases by about 3 dB Correct answer.
  4. It increases by about 3 dB

Explanation

Each halving of the split ratio removes one factor of two, which corresponds to about 3 dB. A 1:16 splitter therefore has roughly 3 dB less splitting loss than a 1:32 splitter, leaving more margin for the branch.

Question 32Fiber optics fundamentals and home fiber architectures

A technician is choosing fiber for a short in-home run that will be stapled along skirting boards and bent around door frames. Which characteristic matters most in this selection?

  1. Macrobend insensitivity at 1550 nm and 1625 nm Correct answer.
  2. Low water-peak attenuation at 1383 nm
  3. Graded-index multimode core profile
  4. High numerical aperture for large-core coupling

Explanation

Indoor routing creates tight bends that can radiate light out of the core, so bend-insensitive single-mode fiber rated for small bend radii is the appropriate choice. Water-peak performance and multimode profiles address different concerns and do not protect against bend loss.

Question 33Fiber optics fundamentals and home fiber architectures

During a power meter measurement at an ONT, the technician records -24.8 dBm at 1490 nm. What does this reading indicate?

  1. The insertion loss of the drop cable in decibels
  2. The return loss of the ONT connector
  3. The received optical power level at that port Correct answer.
  4. The wavelength drift of the OLT transmitter

Explanation

A power meter reading in dBm reports absolute optical power arriving at the port, which is then compared with the ONT receiver sensitivity range. Insertion loss and return loss are relative decibel quantities and require a reference measurement.

Question 34Fiber optics fundamentals and home fiber architectures

An FTTH provider deploys a PON with a 1:64 split and later wants to add subscribers beyond the port capacity. Which approach is consistent with PON architecture?

  1. Reduce the downstream wavelength spacing to create more channels
  2. Add a second PON port at the OLT and split the served area between ports Correct answer.
  3. Increase the transmit power of each ONT to reach the OLT
  4. Replace the passive splitters with electrically powered regenerators

Explanation

PON capacity is extended by adding OLT ports, and often additional feeder fibers, then redistributing subscribers among them. Passive splitting remains in place, and each port keeps its own shared bandwidth and power budget.

Question 35Fiber optics fundamentals and home fiber architectures

A technician must join a drop cable to a pigtail inside a small wall box where a fusion splicer cannot be used. Which method is appropriate?

  1. Fusion splice
  2. Wavelength division multiplexing
  3. Mechanical splice Correct answer.
  4. Optical add-drop multiplexing

Explanation

A mechanical splice aligns and indexes two cleaved fibers using an index-matching gel and a clamp, requiring no fusion splicer or arc. It typically has slightly higher loss than a fusion splice but is well suited to confined field locations.

Question 36Fiber optics fundamentals and home fiber architectures

Why does a PON use a single fiber for both downstream and upstream traffic rather than separate fibers to each home?

  1. It removes the need for a loss budget on each branch
  2. It reduces feeder and distribution fiber count and outside-plant cost Correct answer.
  3. It allows the splitter to amplify the upstream signal
  4. It eliminates the need for any wavelength filtering at the ONT

Explanation

Bidirectional transmission over one fiber with different upstream and downstream wavelengths greatly reduces the amount of fiber and splicing needed in the feeder and distribution network. The ONT still needs wavelength-selective components to separate the bands.

Question 37Fiber optics fundamentals and home fiber architectures

A technician inspects a cleaved fiber before splicing and sees a rough, angled end face with a lip. What is the correct action?

  1. Proceed, because the splicer arc will smooth the end face
  2. Increase the arc duration to compensate for the defect
  3. Re-cleave the fiber and inspect again before splicing Correct answer.
  4. Wet the fiber end with index-matching gel before splicing

Explanation

A cleave must be flat and perpendicular so the two end faces can be aligned and fused with low loss. Rough or angled cleaves cause high splice loss and should be corrected by re-cleaving rather than compensated for in the splicer settings.

Question 38Fiber optics fundamentals and home fiber architectures

A home is offered both a GPON-based FTTH service and a point-to-point active Ethernet fiber service. Which statement correctly distinguishes them?

  1. GPON gives each subscriber a dedicated fiber, while active Ethernet shares a single fiber through splitters
  2. GPON shares one OLT port among many subscribers through passive splitters, while active Ethernet gives each subscriber a dedicated fiber and switch port Correct answer.
  3. Active Ethernet uses only multimode fiber, while GPON uses only single-mode fiber
  4. Both architectures require powered equipment inside the distribution network between OLT and subscriber

Explanation

A PON concentrates many subscribers onto one OLT port using passive splitters in the field, sharing the port's bandwidth. Point-to-point active Ethernet instead runs a dedicated fiber from the central switch to each subscriber, giving dedicated capacity at higher fiber count.

Question 39Fiber optics fundamentals and home fiber architectures

A PON branch shows correct loss at 1310 nm but excessive loss at 1490 nm, with a visible tight coil of drop cable fixed to a wall. Which explanation is most consistent with these observations?

  1. A failed splitter port causing uniform loss at all wavelengths
  2. A contaminated connector end face at the ONT
  3. Macrobend loss in the coiled drop cable affecting the longer wavelength more Correct answer.
  4. A misconfigured upstream transmit power at the ONT

Explanation

Bend-induced loss grows at longer wavelengths, so a tight coil can degrade 1490 nm and 1550 nm while leaving 1310 nm nearly unaffected. Connector contamination and splitter faults would normally raise loss across all wavelengths.

Question 40Fiber optics fundamentals and home fiber architectures

An engineer must decide whether a PON branch can support an additional 1:8 splitter stage. Which analysis is most relevant?

  1. Measuring the return loss of the OLT transmitter alone
  2. Comparing the added splitting loss plus connector losses against the remaining power budget margin Correct answer.
  3. Checking the ONT Ethernet port speed
  4. Counting the number of spare ports on the OLT chassis

Explanation

Cascading another splitter adds both its splitting loss and additional connectors and splices to the branch, so the decision rests on whether the remaining budget margin covers that increase. Port counts, Ethernet speeds, and single-point return loss do not answer the budget question.

Question 41Fiber optic components for the home: cable, connectors and hardware

In a typical FTTH drop installation, which fiber type is most commonly used inside the home because of its tight-buffer construction and flexible bend radius?

  1. Large-core plastic optical fiber
  2. OM4 50/125 µm multimode
  3. OS2 single-mode with tight buffer Correct answer.
  4. OM1 62.5/125 µm multimode

Explanation

FTTH drop and in-home cabling almost always carries a single-mode signal from the PON, so OS2 tight-buffer cable is used for its small bend radius and rugged handling. Multimode grades are used in short-reach data links, not in PON drops.

Question 42Fiber optic components for the home: cable, connectors and hardware

Which connector polish geometry is standard on SC and LC connectors used for FTTH ONT and patch-panel connections?

  1. PC with flat endface
  2. ST bayonet with flat endface
  3. UPC with domed endface Correct answer.
  4. APC with 8-degree angled endface

Explanation

UPC uses a domed, physically contacting endface and is the common polish for SC and LC connectors in FTTH equipment. APC is angled and appears mainly on RF-video or high-reflection-sensitive links.

Question 43Fiber optic components for the home: cable, connectors and hardware

A technician must join two field fibers permanently with the lowest possible loss inside a small subscriber enclosure. Which method is most appropriate?

  1. SC/APC connector pair
  2. Mechanical splice with index-matching gel
  3. Bare fiber twist and heat-shrink
  4. Fusion splicing Correct answer.

Explanation

Fusion splicing welds the fibers into a continuous glass joint and gives the lowest loss and best long-term reliability for permanent splices. Mechanical splices are acceptable but typically show higher loss and reflection.

Question 44Fiber optic components for the home: cable, connectors and hardware

What is the primary purpose of the strength members in an indoor drop cable?

  1. Block ultraviolet light from degrading the jacket
  2. Terminate the cable at the ONT
  3. Provide tensile load bearing so the fiber is not strained Correct answer.
  4. Carry the optical signal alongside the fiber

Explanation

Aramid yarn or FRP rods take the pulling and hanging loads so the glass fiber itself carries no tension. The fiber alone is fragile and would fail if stressed mechanically.

Question 45Fiber optic components for the home: cable, connectors and hardware

Which color is the standard jacket color for single-mode OS2 indoor cable?

  1. Magenta
  2. Aqua
  3. Orange
  4. Yellow Correct answer.

Explanation

Yellow identifies single-mode OS2 cable in the common color code. Aqua and magenta mark multimode grades, and orange marks older OM1/OM2 multimode.

Question 46Fiber optic components for the home: cable, connectors and hardware

An installer is mounting a small wall box for an ONT and needs to secure the drop cable so it cannot be pulled tight. What is the accepted practice?

  1. Coil the cable around the ONT power cord
  2. Tie the cable to a conduit with a tight knot
  3. Leave a service loop and use cable clamps that do not crush the jacket Correct answer.
  4. Staple the cable tightly every 10 cm

Explanation

A slack service loop plus non-crushing clamps keeps tension off the connector and protects the fiber bend radius. Tight staples or knots deform the cable and can break the fiber.

Question 47Fiber optic components for the home: cable, connectors and hardware

Which tool is used to strip the 250 µm coating from a single fiber before cleaving and splicing?

  1. Jacket slitter
  2. Miller stripping tool Correct answer.
  3. Cleaver
  4. Visual fault locator

Explanation

A Miller-style stripper has sized notches for removing the 250 µm acrylate coating without nicking the glass. Jacket slitters are for the outer cable sheath, not the fiber coating.

Question 48Fiber optic components for the home: cable, connectors and hardware

Which connector style uses a 2.5 mm ferrule and a square push-pull latch, commonly found on older FTTH ONTs and patch panels?

  1. MTRJ
  2. MU
  3. SC Correct answer.
  4. LC

Explanation

The SC connector uses a 2.5 mm ferrule with a square body and push-pull latch. LC uses a 1.25 mm ferrule, and MTRJ uses a duplex pin-and-socket design.

Question 49Fiber optic components for the home: cable, connectors and hardware

A field technician is installing a pre-terminated drop cable with an SC/APC connector into an ONT port. Which action protects the connector and the measurement?

  1. Apply index-matching gel to the connector tip
  2. Mate the connector dry and clean it only if the link fails
  3. Clean both endfaces and verify the port accepts an APC polish before mating Correct answer.
  4. Remove the dust cap and blow on the ferrule to clear debris

Explanation

Dirt is the leading cause of connector loss and damage, so endfaces must be inspected and cleaned before mating. The port polish must also match, because APC and UPC endfaces do not mate correctly.

Question 50Fiber optic components for the home: cable, connectors and hardware

A drop cable must make a 90-degree turn inside a small wall box. Which practice respects the fiber's bend radius?

  1. Form a gentle loop no tighter than the cable's rated minimum bend radius Correct answer.
  2. Kink the cable and cover it with the faceplate
  3. Coil the cable around a screwdriver shaft
  4. Fold the cable sharply and tape it down

Explanation

Bending below the rated minimum radius causes macrobending loss and can crack the fiber. A gentle loop within the cable's specification keeps attenuation acceptable.