You dont have javascript enabled! Please enable it! MCQ in Fiber Optics Communications Part 4 | ECE Board Exam

# MCQ in Fiber Optics Communications Part 4 | ECE Board Exam

This is the Multiples Choice Questions Part 4 of the Series in Fiber Optics Communications as one of the Communications Engineering topics. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize yourself with each and every question compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic Systems and Technologies, Communications Books, Journals, and other Communications References.

#### MCQ Topic Outline included in ECE Board Exam Syllabi

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

#### Continue Practice Exam Test Questions Part 4 of the Series

Choose the letter of the best answer in each questions.

151. A device that was constructed from mirrors and selenium detectors that transmitted sound waves over a beam of light.

A. lightphone

B. photophone

C. cameraphone

D. walletphone

Solution:

152. Which fiber-optic system is better?

A. 3 repeaters

B. 8 repeaters

C. 11 repeaters

D. 20 repeaters

Solution:

153. What is the frequency limit of a copper wire?

A. approximately 0.5 MHz

B. approximately 1.0 MHz

C. approximately 40 GHz

D. none of the above

Solution:

154. They were granted patents for scanning and transmitting television images through uncoated fiber cables.

A. Baird and Hansel

B. Bockham and Kao

C. Kapron and Keck

D. Maiman and Schawlow

Solution:

155. The product of the bit rate and distance of a fiber-optic system is 2 Gbits-km/s. What is the maximum rate at 5 km?

A. 100 Mbits/s

B. 200 Mbits/s

C. 400 Mbits/s

D. 1000 Gbits/s

Solution:

156. Approximately what is the frequency limit of the optical fiber?

A. 20 MHz

B. 1 MHz

C. 100 MHz

D. 40 GHz

Solution:

157. They experimented with light transmission cables through bundle of fibers and lead to the development of flexible fiberscope.

A. Townes, Schawlow and Kao

B. Maiman, Kao and Bockham

C. Maurer, Kapron and Keck

D. Van Heel, Hopkins and Kapany

Solution:

158. Photodiodes operate properly with

A. forward bias

B. reverse bias

C. neither forward nor reverse bias

D. either forward or reverse bias

Solution:

159. He coined the term โfiber opticsโ in 1956.

A. Kapany

B. Kao

C. Bockham

D. Keck

Solution:

160. They wrote a paper describing how it was possible to use stimulated emission for amplifying light waves (laser) as well as microwaves (maser).

A. Theodore Maiman

B. KC Kao and GA Bockham

C. Charles Townes and Arthur Schawlow

D. Kapron, Keck and Maurer

Solution:

161. The scientist who built the first optical maser

A. Charles Townes

B. GA Bockham

C. Theodore Maiman

D. ACS Van Heel

Solution:

162. A single fiber can handle as many voice channels as

A. a pair of copper conductors

B. a 1500-pair cable

C. a 500-pair cable

D. a 1000-pair cable

Solution:

163. They proposed a new communication medium using cladded fiber cables.

A. Kao and Bockham

B. Maiman, Kao and Bockham

C. Kapron, Keck and Maurer

D. Maiman and Schawlow

Solution:

164. An incident ray can be defined as

A. a light ray reflected from a flat surface

B. a light directed toward a surface

C. a diffused light ray

D. a light ray that happens periodically

Solution:

165. Developed an optical fiber with losses less that 2 dB/km

A. Kao and Bockham

B. Maiman, Kao and Bockham

C. Maiman and Schawlow

D. Kapron, Keck and Maurer

Solution:

166. The band of light frequencies that are too high to be seen by the human eye.

A. Ultraviolet

B. Visible light

C. Infrared

D. Yellow

Solution:

167. Which of the following is the fastest light sensor?

A. PIN photodiode

B. Photovoltaic diode

C. Photodiode

D. Avalanche photodiode

Solution:

168. Range of infrared

A. 360 nm to 440 nm

B. 670 nm to 10^3 nm

C. 110 nm to 240 nm

D. 770 nm to 10^6 nm

Solution:

169. The term dispersion describes the process of

A. separating light into its component frequencies

B. reflecting light from a smooth surface

C. the process by which light is absorbed by an uneven rough surface

D. light scattering

Solution:

170. The band of light frequencies to which human eye will respond

A. Infrared

B. Visible light

C. Ultraviolet

D. Cosmic ray

Solution:

171. Laser light is very bright because it is

A. pure

B. white

C. coherent

D. monochromatic

Solution:

172. Which of the following is the fastest light sensor?

A. PIN photodiode

B. Photovoltaic diode

C. Photodiode

D. Avalanche photodiode

Solution:

173. Range of wavelength of visible light

A. 670 nm to 10^3 nm

B. 440 nm to 540 nm

C. 110 nm to 240 nm

D. 390 nm to 770 nm

Solution:

174. The band of light frequencies that are too low to be seen by the human eye

A. Infrared

B. X-rays

C. Visible

D. Ultraviolet

Solution:

175. Which of the following terms best describes the reason that light is refracted at different angles?

A. Photon energy changes with wavelength

B. Light is refracted as a function of surface smoothness

C. The angle is determined partly by a and b

D. The angle is determined by the index of the materials

Solution:

176. Range of wavelengths of ultraviolet

A. 670 nm to 10^3 nm

B. 440 nm to 540 nm

C. 110 nm to 240 nm

D. 10 nm to 390 nm

Solution:

177. Single frequency light is called

A. pure

B. intense

C. coherent

D. monochromatic

Solution:

178. The coating in a fiber helps protect fiber from moisture, which reduces the possibility of the occurrence of a detrimental phenomenon called

A. static fatigue

B. mechanical fatigue

C. stress fatigue

D. coating fatigue

Solution:

179. The term critical angle describes

A. the point at which light is refracted

B. the point at which light becomes invisible

C. the point at which light has gone from the refractive mode to the reflective mode

D. the point at which light has crossed the boundary layers from one index to another

Solution:

180. The ratio of the speed of light in air to the speed of light in another substance is called

A. speed factor

B. index of reflection

C. index of refraction

D. speed gain

Solution:

181. The three essential types of fiber commonly used today except:

B. Plastic core and glass cladding

C. Glass core and glass cladding (SCS)

D. Glass core and plastic cladding (PCS)

Solution:

182. What phenomenon will result if the glass fiber is exposed to long periods of high humidity?

A. stress fatigue

B. core corrosion

C. stress corrosion

Solution:

183. The law that states โWhen visible light of high frequency electromagnetic radiation illuminates a metallic surface, electrons are emittedโ is known as ____________.

A. Einstein law of photon

B. Marconiโs law

C. Maxwellโs law

D. Plankโs law

Solution:

184. Both LEDs and ILDs operate correctly with

A. forward bias

B. reverse bias

C. neither forward nor reverse bias

D. either forward or reverse bias

Solution:

185. Any energy above the ground state is called ___________.

A. normal state

B. above-ground state

C. excited state

D. spontaneous state

Solution:

186. The process of decaying from one energy level to another energy level is called __________.

A. Spontaneous emission

B. Excited emission

C. Absorption

D. Any of these

Solution:

187. The process of moving from one energy level to another is called ____________.

A. Spontaneous emission

B. Excited emission

C. Absorption

D. Spontaneous decay

Solution:

188. Most fiber optic light sources emit light in which spectrum?

A. visible

B. infrared

C. ultraviolet

D. X-ray

Solution:

189. A packet of energy which is equal to the difference between the two energy levels.

A. Photons

B. Electronvolt

C. Quantum

D. Quanta

Solution:

190. It is the science of measuring only light waves that are visible to the human eye.

B. Photometry

C. Ophthalmology

D. Optometry

Solution:

191. The refractive index number is

A. a number which compares the transparency of a material with that of air

B. a number of assigned by the manufacturer to the fiber in question

C. a number which determines the core diameter

D. a term describing core elasticity

Solution:

192. It is a science of measuring light throughout the entire electromagnetic spectrum

B. Photometry

C. Ophthalmology

D. Optometry

Solution:

193. Which light emitter is preferred for high-speed data in a fiber-optic system?

A. incandescent

B. LED

C. neon

D. laser

Solution:

194. Light intensity is generally described in terms of __________ and measured in _________.

A. Luminous flux density; Lumens per unit area

B. Luminous flux intensity; Lumens per unit area

C. Luminous flux density; Lumens per unit volume

D. Luminous flux intensity; Lumens per unit volume

Solution:

195. In radiometric terms, it measures the rate at which electromagnetic waves transfer light energy

B. Optical impedance

C. Optical illusion

D. Optical power

Solution:

196. It is described as the flow of light energy past a given point in a specified time

B. Optical impedance

C. Optical illusion

D. Optical power

Solution:

197. The term single mode and multimode are best described as

A. a number of fibers placed into fiber-optic cable

B. the number of voice channels each fiber can support

C. the number of wavelengths each fiber can support

D. the index number

Solution:

198. Optical power is sometimes called __________.

Solution:

199. In refraction that occurs in air/glass interfaces, among the visible light, which is bent the most?

A. red

B. violet

C. yellow

D. green

Solution:

200. Fiber-optic cables with attenuation of 1.8, 3.4, 5.9 and 18 dB are linked together. The total loss is

A. 7.5 dB

B. 19.8 dB

C. 29.1 dB

D. 650 dB

Solution:

### Complete List of MCQ in Communications Engineering per topic

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