WGU D413 Telecomm and Wireless Communications - D413 - Review Q&A Ch.3 with 100% accurate solutions

Describe how data is transferred across a fiber-optic cable.

Data is transferred across a fiber-optic cable using light signals that travel through the core of the cable. The core is surrounded by cladding that reflects light back into the core, allowing it to travel long distances without significant loss.

List advantages of fiber-optic cable over copper-core cable.

Advantages include higher bandwidth, greater immunity to electromagnetic interference (EMI), longer transmission distances, and lighter weight.

Light is measured by its _____.

Light is measured by its wavelength.

What is the wavelength range of visible light?

The wavelength range of visible light is approximately 400 to 700 nanometers (nm).

What are the three common wavelengths associated with fiber-optic cable?

The three common wavelengths are 850 nm, 1310 nm, and 1550 nm.

What is dispersion?

Dispersion refers to the spreading of light pulses as they travel down the fiber-optic cable, which can cause distortion and limit the transmission distance.

Name three physical factors that contribute to extrinsic losses.

Extrinsic losses can be caused by factors such as bending of the cable, imperfections in connectors, and contamination on the fiber surfaces.

Describe Fresnel reflection loss.

Fresnel reflection loss occurs when a portion of the light signal is reflected back at a connection point due to differences in refractive indices between materials.

What are the two classifications of fiber-optic cable based on the diameter of the core?

Single-mode fiber (SMF) and multimode fiber (MMF).

How does the diameter of the fiber-optic cable core affect the distance light can travel?

A larger core diameter (as in multimode fiber) allows light to travel shorter distances without dispersion compared to single-mode fiber, which has a smaller core.

Fiber-optic cable core diameter is expressed in _____.

Micrometers (µm) or sometimes in terms of the mode field diameter (MFD).

What are the two most common sizes of multimode fiber-optic cable?

62.5 µm (OM1) and 50 µm (OM2, OM3, OM4, OM5).

What is the IEEE 802 standard for Gigabit Ethernet?

IEEE 802.3ab.

What is the IEEE 802 standard for 10 Gigabit Ethernet?

IEEE 802.3ae.

What do the following 10 Gigabit Ethernet acronyms represent: SW, LW, and EW?

SW (Short Wave), LW (Long Wave), and EW (Extended Wave) refer to different types of 10 Gigabit Ethernet optics and transmission distances.

What is the range of FDDI?

FDDI operates over a maximum ring length of 200 kilometers.

Why does FDDI use two rings of cable?

FDDI uses dual rings for redundancy and reliability; if one ring fails, the network can still operate using the second ring.

List the five most common types of fiber-optic cable connector.

SC, LC, ST, MTP/MPO, and FC.

What are some common causes of attenuation associated with fiber-optic cable splices?

Attenuation in splices can result from misalignment of fiber cores, contamination, and imperfect joining of fiber ends.

Using heat to join two fiber-optic cores is called a(n) _____ splice.

Fusion splice.

What is required to test a short run of fiber-optic cable?

A light source and a power meter (or optical loss test set).

What device is commonly used to test long runs of fiber-optic cable?

Optical Time Domain Reflectometer (OTDR).

What principle of fiber-optic cable loss does the OTDR use for measurements?

OTDR measures loss by sending a pulse of light into the fiber and analyzing the reflections (backscatter) caused by changes in the fiber.

Deepak is a network administrator for a defense contractor. He is deeply concerned about eavesdropping on the signal. Which of the following network media is typically the most secure from eavesdropping devices or security taps?

A. Fiber-optic cable

B. Copper-core cable

C. Wireless

D. Infrared

Answer: A. Fiber-optic cable.

Explanation: Fiber-optic cables are the most secure against eavesdropping because they do not emit electromagnetic signals that can be intercepted without physical access to the cable.

Identify the following connector.

A. SC

B. ST

C. RJ-45

D. BNC

Answer: B. SC.

Explanation: SC connectors are commonly used with fiber-optic cables.

Identify the following connector.

A. SC

B. ST

C. RJ-45

D. BNC

Answer: A. ST.

Explanation: ST connectors are also commonly used with fiber-optic cables.

Where is fiber-optic cable typically found? (Select all that apply.)

A. In network backbones.

B. In network segments that are exposed to electromagnetic interference.

C. Where security from wiretaps is of great concern.

D. In network segments requiring slow data transmission rates.

Where is fiber-optic cable typically found? (Select all that apply.)

A. In network backbones.

B. In network segments that are exposed to electromagnetic interference.

C. Where security from wiretaps is of great concern.

D. In network segments requiring slow data transmission rates.

A. In network backbones.

C. Where security from wiretaps is of great concern.

Explanation: Fiber-optic cables are used in network backbones for high-speed and long-distance transmission, and where security is a concern due to their immunity to tapping.

Gerard is a network administrator for a large financial company. He is overseeing the implementation of new fiber optic cable. He is concerned about distortion of the light wave as it reflects off the core cladding. Which of the following best describes this?

A. Scattering

B. Attenuation

C. Diffusion

D. Reflection

D. Reflection.

Explanation: Reflection refers to the bouncing back of light waves when they encounter a change in refractive index, such as at the core-cladding interface.

Juanita is trying to select cable for her companies CAN. She needs cable that supports a very long distance. Which of the following would be her best choice?

A. 10GbaseER

B. 10GBaseLX

C. 1000BaseLX

D. 100BaseCX

A. 10GbaseER.

Explanation: 10GBase-ER is suitable for long-distance Ethernet applications (ER stands for Extended Reach).

According to the ANSI/TIA/EIA standards for backbone distribution inside a premise, what is the maximum recommended distance for multimode fiber-optic cable?

A. 100 meters

B. 200 meters

C. 500 meters

D. 2000 meters

B. 200 meters.

Explanation: ANSI/TIA/EIA standards recommend a maximum distance of 200 meters for multimode fiber in backbone distribution.

You are installing a new FDDI interface. You need to connect the appropriate media to that interface. What type of networking media is used in FDDI?

A. Fiber-optic multimode

B. Fiber-optic single-mode

C. UTP

D. All the above materials can be used for FDDI.

A. Fiber-optic multimode.

Explanation: FDDI uses multimode fiber-optic cable for its dual-ring topology.

Which is a correct description of the FDDI topology?

A. Star

B. Bus

C. Single ring

D. Dual ring

D. Dual ring.

Explanation: FDDI uses a dual-ring topology for redundancy and reliability in data transmission.

The loss of signal strength in the core of a fiber-optic cable caused by impurities in the core is referred to as _____.

A. scattering

B. dispersion

C. diffusion

D. reflection

A. Scattering.

Explanation: Scattering refers to the random redirection of light within the fiber core due to impurities or imperfections.