MCQs in Fiber Optics Communications Part VI

This is the Multiples Choice Questions Part 6 of the Series in Fiber Optics Communications as one of the Communications Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies, Communications Books, Journals and other Communications References.

Online Questions and Answers Topic Outline

• MCQs in Principles of Light Transmission
• MCQs in Types of Light Sources, Laser, LED
• MCQs in Light Detectors
• MCQs in Modulation and Waveform
• MCQs in System Design
• MCQs in General application
• MCQs in System Bandwidth
• MCQs in Splicing Techniques

MCQs in Fiber Optics Communications Series

Following is the list of multiple choice questions in this brand new series:

Optical Fiber Communications MCQs

PART 1: MCQs from Number 1 – 50                        Answer key: PART I

PART 2: MCQs from Number 51 – 100                   Answer key: PART II

PART 3: MCQs from Number 101 – 150                 Answer key: PART III

PART 4: MCQs from Number 151 – 200                 Answer key: PART IV

PART 5: MCQs from Number 201 – 250                 Answer key: PART V

PART 6: MCQs from Number 251 – 300                 Answer key: PART VI

SEE: More Questions and Answers in Fiber Optics Communications

Continue Practice Exam Test Questions Part VI of the Series

251. Type of lasers that use organic dyes enclosed in glass tube for an active medium.

• A. liquid lasers
• B. plasma lasers
• C. neon lasers
• D. ruby lasers

252. A popular light wavelength fiber-optic cable is

• A. 0.7 micrometer
• B. 1.3 micrometer
• C. 1.5 micrometer
• D. 1.8 micrometer

253. Type of lasers that use solid, cylindrical crystals such as ruby

• A. solid lasers
• B. ILD
• C. gas lasers
• D. liquid lasers

254. Type of lasers that are made from semiconductor ph-junctions commonly called ILDs

• A. semiconductor lasers
• B. liquid lasers
• C. plasma lasers
• D. gas lasers

255. Which of the following is not a common application of fiber-optic cable?

• A. computer networks
• B. long-distance telephone system
• C. closed-circuit TV
• D. consumer TV

256. Total internal reflection takes place if the light ray strikes the interface at an angle with what relationship to the critical angle?

• A. less than
• B. greater than
• C. equal to
• D. zero

257. Loss comparisons between fusion splices an mechanical splices

• A. 1:10
• B. 10:1
• C. 20:1
• D. 1:20

258. The operation of a fiber-optic cable is based on the principle of

• A. refraction
• B. reflection
• C. dispersion
• D. absorption

259. Which of the following is not a common type of fiber-optic cable?

• A. single-mode step-index
• B. multimode graded-index
• C. single-mode graded-index
• D. multimode step-index

260. Cable attenuation is usually expressed in terms of

• A. loss per foot
• B. dB/km
• C. intensity per mile
• D. voltage drop per inch

261. Which cable length has the highest attenuation?

• A. 1 km
• B. 2 km
• C. 95 ft.
• D. 500 ft.

262. The mechanical splice is best suited for

• A. quicker installation under ideal condition
• B. minimum attenuation losses
• C. field service conditions
• D. situations in which cost of equipment is not a factor

263. The upper pulse rate and information-carrying capacity of a cable is limited by

• A. pulse shortening
• B. attenuation
• C. light leakage
• D. modal dispersion

264. The core of a fiber-optic cable is made of

• A. air
• B. glass
• C. diamond
• D. quartz

265. The core of fiber-optic cable is surrounded by

• A. wire braid shield
• B. Keviar
• C. cladding
• D. plastic insulation

266. The speed of light in plastic compared to the speed of light in air is

• A. less
• B. more
• C. the same
• D. zero

267. Which of the following is not a major benefit of a fiber-optic cable?

• A. immunity from interference
• B. no electrical safety problems
• C. excellent data security
• D. lower cost

268. EMD is best described by which statement?

• A. 70 percent of the core diameter and 70% of the fiber NA should be filled with light.
• B. 70 percent of the fiber diameter and 70% of the cone of acceptance should be filled with light.
• C. 70 percent of input light should be measured at the output.
• D. 70 percent of the unwanted wavelengths should be attenuated by the fiber.

269. The main benefit of light wave communications over microwaves or any other communications media are

• A. lower cost
• B. better security
• C. wider bandwidth
• D. freedom from interface

270. Which of the following is not a part of the optical spectrum?

• A. infrared
• B. ultraviolet
• C. visible color
• D. x-rays

271. The wavelength of a visible extends from

• A. 0.8 to 1.6 um
• B. 400 to 750 nm
• C. 200 to 660 nm
• D. 700 to 1200 nm

272. Single-mode step-index cable has a core diameter in the range of

• A. 100 to 1000 micrometer
• B. 50 to 100 micrometer
• C. 2 to 15 micrometer
• D. 5 to 20 micrometer

273. Refraction is the

• A. bending of light
• B. reflection of light waves
• C. distortion of light waves
• D. diffusion of light waves

274. Which of the following cables will have the highest launch power capability?

• A. 50/125/0.2
• B. 85/125/0.275
• C. 62.5/125/0.275
• D. 100/140/0.3

275. Which type of fiber-optic cable is the most widely used?

• A. single-mode step-index
• B. multimode step-index
• C. single-mode graded index
• D. multimode graded index

276. The term power budgeting refers to

• A. the cost of cable, connectors, equipment and installation
• B. the loss of power due to defective components
• C. the total power available minus the attenuation losses
• D. the comparative costs of fiber and copper installations

277. It refers to the abrupt of change in refractive index from core to clad

• A. step index
• B. graded index
• C. semi-graded index
• D. half step index

Complete List of MCQs in Communications Engineering per topic

Series of Multiple Choice Questions in Electronics Systems and Technologies

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