McqMate
| 101. |
3dB optical bandwidth is always ___________ the 3dB electrical bandwidth. |
| A. | smaller than |
| B. | larger than |
| C. | negligible than |
| D. | equal to |
| Answer» B. larger than | |
| 102. |
A multimode graded index fiber exhibits a total pulse broadening of 0.15μsover a distance of 16 km. Estimate the maximum possible bandwidth, assuming no intersymbol interference. |
| A. | 4.6 mhz |
| B. | 3.9 mhz |
| C. | 3.3 mhz |
| D. | 4.2 mhz |
| Answer» C. 3.3 mhz | |
| 103. |
What is pulse dispersion per unit length if for a graded index fiber, 0.1μs pulse broadening is seen over a distance of 13 km? |
| A. | 6.12ns/km |
| B. | 7.69ns/km |
| C. | 10.29ns/km |
| D. | 8.23ns/km |
| Answer» B. 7.69ns/km | |
| 104. |
Chromatic dispersion is also called as intermodal dispersion. State whether the given statement true or false. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 105. |
Chromatic dispersion is also called as intermodal dispersion. State true or false |
| A. | true |
| B. | false |
| Answer» B. false | |
| 106. |
The optical source used in a fiber is an injection laser with a relative spectral width σλ/λ of 0.0011 at a wavelength of 0.70μm. Estimate the RMS spectral width. |
| A. | 1.2 nm |
| B. | 1.3 nm |
| C. | 0.77 nm |
| D. | 0.98 nm |
| Answer» C. 0.77 nm | |
| 107. |
In waveguide dispersion, refractive index is independent of |
| A. | bit rate |
| B. | index difference |
| C. | velocity of medium |
| D. | wavelength |
| Answer» D. wavelength | |
| 108. |
Intermodal dispersion occurring in a large amount in multimode step index fiber results in |
| A. | propagation of the fiber |
| B. | propagating through the fiber |
| C. | pulse broadening at output |
| D. | attenuation of waves |
| Answer» C. pulse broadening at output | |
| 109. |
After Total Internal Reflection the Meridional ray |
| A. | makes an angle equal to acceptance angle with the axial ray |
| B. | makes an angle equal to critical angle with the axial ray |
| C. | travels parallel equal to critical angle with the axial ray |
| D. | makes an angle equal to critical angle with the axial ray |
| Answer» D. makes an angle equal to critical angle with the axial ray | |
| 110. |
Consider a single mode fiber having core refractive index n1= 1.5. |
| A. | 1.00μsec |
| B. | 0.06μsec |
| C. | 0.90μsec |
| D. | 0.30μsec |
| Answer» B. 0.06μsec | |
| 111. |
A 4 km optical link consists of multimode step index fiber with core refractive index of 1.3 and a relative refractive index difference of 1%. Find the delay difference between the slowest and fastest modes at the fiber output. |
| A. | 0.173 μsec |
| B. | 0.152 μsec |
| C. | 0.96 μsec |
| D. | 0.121 μsec |
| Answer» A. 0.173 μsec | |
| 112. |
A multimode step-index fiber has a core refractive index of 1.5 and relative refractive index difference of 1%. The length of the optical link is 6 km. Estimate the RMS pulse broadening due to intermodal dispersion on the link. |
| A. | 92.6 ns |
| B. | 86.7 ns |
| C. | 69.3 ns |
| D. | 68.32 ns |
| Answer» B. 86.7 ns | |
| 113. |
The differential attenuation of modes reduces intermodal pulse broadening on a multimode optical link. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 114. |
The index profile of a core of multimode graded index fiber is given by- |
| A. | n (r) = n1 [1 – 2Δ(r2/a)2]1/2; r<a |
| B. | n (r) = n1 [3 – 2Δ(r2/a)2]1/2; r<a |
| C. | n (r) = n1 [5 – 2Δ(r2/a)2]1/2; r>a |
| D. | n (r) = n1 [1 – 2Δ(r2/a)2]1/2; r<a |
| Answer» D. n (r) = n1 [1 – 2Δ(r2/a)2]1/2; r<a | |
| 115. |
Intermodal dispersion in multimode fibers is minimized with the use of step-index fibers. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 116. |
Estimate RMS pulse broadening per km due to intermodal dispersion for multimode step index fiber where length of fiber is 4 km and pulse broadening per km is 80.6 ns. |
| A. | 18.23ns/km |
| B. | 20.15ns/km |
| C. | 26.93ns/km |
| D. | 10.23ns/km |
| Answer» B. 20.15ns/km | |
| 117. |
Practical pulse broadening value for graded index fiber lies in the range of |
| A. | 0.9 to 1.2 ns/km |
| B. | 0.2 to 1 ns/km |
| C. | 0.23 to 5 ns/km |
| D. | 0.45 to 8 ns/km |
| Answer» B. 0.2 to 1 ns/km | |
| 118. |
The nonlinear effects in optical fibers are large. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 119. |
How many categories of nonlinear effects are seen in optical fibers? |
| A. | one |
| B. | two |
| C. | three |
| D. | four |
| Answer» B. two | |
| 120. |
Which of the following is not related to Kerr effects? |
| A. | self-phase modulation |
| B. | cross-phase modulation |
| C. | four-wave mixing |
| D. | stimulated raman scattering |
| Answer» D. stimulated raman scattering | |
| 121. |
Linear scattering effects are _______ in nature. |
| A. | elastic |
| B. | non-elastic |
| C. | mechanical |
| D. | electrical |
| Answer» A. elastic | |
| 122. |
Which thing is more dominant in making a fiber function as bidirectional optical amplifier? |
| A. | core material |
| B. | pump source |
| C. | cladding material |
| D. | diameter of fiber |
| Answer» B. pump source | |
| 123. |
_________ semiconductor laser sources generally have broader bandwidths. |
| A. | injection |
| B. | pulsed |
| C. | solid-state |
| D. | silicon hybrid |
| Answer» B. pulsed | |
| 124. |
Nonlinear effects which are defined by the intensity – dependent refractive index of the fiber are called as |
| A. | scattering effects |
| B. | kerr effects |
| C. | raman effects |
| D. | tomlinson effects |
| Answer» B. kerr effects | |
| 125. |
Self-phase modulation causes modifications to the pulse spectrum. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 126. |
Self-phase modulation can be used for |
| A. | enhancing the core diameter |
| B. | wavelength shifting |
| C. | decreasing the attenuation |
| D. | reducing the losses in the fiber |
| Answer» B. wavelength shifting | |
| 127. |
The beating between light at different frequencies or wavelengths in multichannel fiber transmission causes |
| A. | attenuation |
| B. | amplitude modulation of channels |
| C. | phase modulation of channels |
| D. | loss in transmission |
| Answer» C. phase modulation of channels | |
| 128. |
What is different in case of cross-phase modulation from self-phase modulation? |
| A. | overlapping but same pulses |
| B. | overlapping but distinguishable pulses |
| C. | non-overlapping and same pulses |
| D. | non-overlapping but distinguishable pulses |
| Answer» B. overlapping but distinguishable pulses | |
| 129. |
When three wave components co-propagate at angular frequency w1, w2, w3, then a new wave is generated at frequency w4, which is given by |
| A. | w4 = w1-w2-w3 |
| B. | w4 =w1+w2+w3 |
| C. | w4 =w1+w2-w3 |
| D. | w4 =w1-w2+w3 |
| Answer» C. w4 =w1+w2-w3 | |
| 130. |
_____________ results from case of nonlinear dispersion compensation in which the nonlinear dispersion compensation in which the nonlinear dispersion compensation in which the nonlinear chirp caused by self-phase modulation balances, postpones, the temporal broadening induced by group velocity delay. |
| A. | four wave mixing |
| B. | phase modulation |
| C. | soliton propagation |
| D. | raman scattering |
| Answer» C. soliton propagation | |
| 131. |
What is a fundamental necessity in the fabrication of fibers for light transmission? |
| A. | same refractive index for both core and cladding. |
| B. | pump source |
| C. | material composition of fiber |
| D. | variation of refractive index inside the optical fiber |
| Answer» D. variation of refractive index inside the optical fiber | |
| 132. |
Which materials are unsuitable for the fabrication of graded index fiber? |
| A. | glass-like-materials |
| B. | mono-crystalline structures |
| C. | amorphous material |
| D. | silica based material |
| Answer» B. mono-crystalline structures | |
| 133. |
How many different categories are available for the methods of preparing optical glasses? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» B. 2 | |
| 134. |
What is the first stage in liquid-phase-technique? |
| A. | preparation of ultra-pure material powders |
| B. | melting of materials |
| C. | decomposition |
| D. | crystallization |
| Answer» A. preparation of ultra-pure material powders | |
| 135. |
Which processes are involved in the purification stage in liquid-phase-technique? |
| A. | filtration, co-precipitation, re-crystallization |
| B. | decomposition, filtration, drying |
| C. | doping, drying, decomposition |
| D. | filtration, drying, doping |
| Answer» A. filtration, co-precipitation, re-crystallization | |
| 136. |
At what temperature range, does the melting of multi components glass systems takes place? |
| A. | 100-300 degree celsius |
| B. | 600-800 degree celsius |
| C. | 900-1300 degree celsius |
| D. | 1500-1800 degree celsius |
| Answer» C. 900-1300 degree celsius | |
| 137. |
Fiber drawing using preform was useful for the production of graded index fibers. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 138. |
The minute perturbations and impurities in the fiber drawing process using preform technique can result in very high losses of |
| A. | between 500 and 1000 db/km |
| B. | between 100 and 300 db/km |
| C. | between 1200 and 1600 db/km |
| D. | more than 2000 db/km |
| Answer» A. between 500 and 1000 db/km | |
| 139. |
The liquid-phase melting technique is used for the production of fibers |
| A. | with a core diameter of 50μm. |
| B. | with a core diameter less than 100μm. |
| C. | with a core diameter more than 200μm. |
| D. | with a core diameter of 100μm. |
| Answer» C. with a core diameter more than 200μm. | |
| 140. |
Graded index fibers produced by liquid-phase melting technique are less dispersive than step-index fibers. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 141. |
Which of the following is not a technique for fabrication of glass fibers? |
| A. | vapor phase oxidation method |
| B. | direct melt method |
| C. | lave ring method |
| D. | chemical vapor deposition technique |
| Answer» C. lave ring method | |
| 142. |
_____________ technique is method of preparing extremely pure optical glasses. |
| A. | liquid phase (melting) |
| B. | radio frequency induction |
| C. | optical attenuation |
| D. | vapor phase deposition (vpd) |
| Answer» D. vapor phase deposition (vpd) | |
| 143. |
Which of the following materials is not used as a starting material in vapor-phase deposition technique? |
| A. | sicl4 |
| B. | gecl4 |
| C. | o2 |
| D. | b2o3 |
| Answer» D. b2o3 | |
| 144. |
P2O5 is used as a _____________ |
| A. | dopant |
| B. | starting material |
| C. | cladding glass |
| D. | core glass |
| Answer» A. dopant | |
| 145. |
How many types of vapor-phase deposition techniques are present? |
| A. | one |
| B. | two |
| C. | three |
| D. | four |
| Answer» B. two | |
| 146. |
___________ uses flame hydrolysis stems from work on soot processes which were used to prepare the fiber with losses below 20 dB/km. |
| A. | outside vapor phase oxidation |
| B. | chemical vapor deposition |
| C. | liquid phase melting |
| D. | crystallization |
| Answer» A. outside vapor phase oxidation | |
| 147. |
Complete the given reaction |
| A. | 2hcl |
| B. | 4hcl |
| C. | 2cl2 |
| D. | 4cl2 |
| Answer» B. 4hcl | |
| 148. |
In modified chemical vapor deposition, vapor phase reactant such as _________ pass through a hot zone. |
| A. | halide and oxygen |
| B. | halide and hydrogen |
| C. | halide and silica |
| D. | hydroxides and oxygen |
| Answer» A. halide and oxygen | |
| 149. |
_________ is the stimulation of oxide formation by means of non-isothermal plasma maintained at low pressure in a microwave cavity surrounding the tube. |
| A. | outside vapor phase oxidation (ovpo) |
| B. | vapor axial deposition (vad) |
| C. | modified chemical vapor deposition (mcvd) |
| D. | plasma-activated chemical vapor deposition (pcvd) |
| Answer» D. plasma-activated chemical vapor deposition (pcvd) | |
| 150. |
Only graded index fibers are made with the help of vapor-phase deposition techniques. State whether true or false. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 151. |
Modified Chemical Vapor Deposition (MCVD) process is also called as an inside vapor phase oxidation (IVPD) technique. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 152. |
Multimode step index fiber has |
| A. | large core diameter & large numerical aperture |
| B. | large core diameter and small numerical aperture |
| C. | small core diameter and large numerical aperture |
| D. | small core diameter & small numerical aperture |
| Answer» A. large core diameter & large numerical aperture | |
| 153. |
. A typically structured glass multimode step index fiber shows as variation of attenuation in range of |
| A. | 1.2 to 90 db km-1at wavelength 0.69μm |
| B. | 3.2 to 30 db km-1at wavelength 0.59μm |
| C. | 2.6 to 50 db km-1at wavelength 0.85μm |
| D. | 1.6 to 60 db km-1at wavelength 0.90μm |
| Answer» C. 2.6 to 50 db km-1at wavelength 0.85μm | |
| 154. |
A multimode step index fiber has a large core diameter of range |
| A. | 100 to 300 μm |
| B. | 100 to 300 nm |
| C. | 200 to 500 μm |
| D. | 200 to 500 nm |
| Answer» A. 100 to 300 μm | |
| 155. |
Multimode step index fibers have a bandwidth of |
| A. | 2 to 30 mhz km |
| B. | 6 to 50 mhz km |
| C. | 10 to 40 mhz km |
| D. | 8 to 40 mhz km |
| Answer» B. 6 to 50 mhz km | |
| 156. |
Multimode graded index fibers are manufactured from materials with |
| A. | lower purity |
| B. | higher purity than multimode step index fibers. |
| C. | no impurity |
| D. | impurity as same as multimode step index fibers. |
| Answer» B. higher purity than multimode step index fibers. | |
| 157. |
The performance characteristics of multimode graded index fibers are |
| A. | better than multimode step index fibers. |
| B. | same as multimode step index fibers. |
| C. | lesser than multimode step index fibers |
| D. | negligible |
| Answer» A. better than multimode step index fibers. | |
| 158. |
Multimode graded index fibers have overall buffer jackets same as multimode step index fibers but have core diameters |
| A. | larger than multimode step index fibers. |
| B. | smaller than multimode step index fibers. |
| C. | same as that of multimode step index fibers. |
| D. | smaller than single mode step index fibers. |
| Answer» B. smaller than multimode step index fibers. | |
| 159. |
Multimode graded index fibers with wavelength of 0.85μm have numerical aperture of 0.29 have core/cladding diameter of |
| A. | 62.5 μm/125 μm |
| B. | 100μm/140 μm |
| C. | 85 μm/ 125 μm |
| D. | 50 μm/ 125μm |
| Answer» B. 100μm/140 μm | |
| 160. |
Multimode graded index fibers use incoherent source only. State whether the following statement is true or false. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 161. |
In single mode fibers, the most beneficial index profile is |
| A. | step index |
| B. | graded index |
| C. | step and graded index |
| D. | coaxial cable |
| Answer» B. graded index | |
| 162. |
The fibers mostly not used nowadays for optical fiber communication system are |
| A. | single mode fibers |
| B. | multimode step fibers |
| C. | coaxial cables |
| D. | multimode graded index fibers |
| Answer» A. single mode fibers | |
| 163. |
Single mode fibers allow single mode propagation; the cladding diameter must be at least |
| A. | twice the core diameter |
| B. | thrice the core diameter |
| C. | five times the core diameter |
| D. | ten times the core diameter |
| Answer» D. ten times the core diameter | |
| 164. |
A fiber which is referred as non-dispersive shifted fiber is |
| A. | coaxial cables |
| B. | standard single mode fibers |
| C. | standard multimode fibers |
| D. | non zero dispersion shifted fibers |
| Answer» B. standard single mode fibers | |
| 165. |
Standard single mode fibers (SSMF) are utilized mainly for operation in |
| A. | c-band |
| B. | l-band |
| C. | o-band |
| D. | c-band and l-band |
| Answer» C. o-band | |
| 166. |
Fiber mostly suited in single-wavelength transmission in O-band is |
| A. | low-water-peak non dispersion-shifted fibers |
| B. | standard single mode fibers |
| C. | low minimized fibers |
| D. | non-zero-dispersion-shifted fibers |
| Answer» B. standard single mode fibers | |
| 167. |
When optical fibers are to be installed in a working environment, the most important parameter to be considered is |
| A. | transmission property of the fiber |
| B. | mechanical property of the fiber |
| C. | core cladding ratio of the fiber |
| D. | numerical aperture of the fiber |
| Answer» B. mechanical property of the fiber | |
| 168. |
It is not important to cover these optical fibers required for transmission. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 169. |
Optical fibers for communication use are mostly fabricated from |
| A. | plastic |
| B. | silica or multicomponent glass |
| C. | ceramics |
| D. | copper |
| Answer» B. silica or multicomponent glass | |
| 170. |
An Si-O bond with a Young’s modulus of 9*1010Nm-1 have an elliptical crack of depth 7nm. The surface energy is 2.29 J. Estimate fracture stress for silica fiber. |
| A. | 4.32*109nm-1 |
| B. | 6.32*109nm-1 |
| C. | 5.2*109nm-1 |
| D. | 3*109nm-1 |
| Answer» A. 4.32*109nm-1 | |
| 171. |
Calculate percentage strain at break for a Si-O bond with a fracture strength of 3.52*1010Nm-1 and Young’s modulus of 9 *109Nm-1. |
| A. | 3.1 % |
| B. | 2.8 % |
| C. | 4.5 % |
| D. | 3.9 % |
| Answer» D. 3.9 % | |
| 172. |
Stress corrosion must be considered while designing and testing optical fiber cables. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 173. |
Which statistics are used for calculations of strengths of optical fibers? |
| A. | edwin statistics |
| B. | newton statistics |
| C. | wei-bull statistics |
| D. | gamma statistics |
| Answer» C. wei-bull statistics | |
| 174. |
What does n denotes in the equation given below, if vc is the crack velocity; A is the constant for the fiber material and KI is the strength intensity factor? |
| A. | refractive index |
| B. | stress corrosion susceptibility |
| C. | strain |
| D. | young’s modulus |
| Answer» B. stress corrosion susceptibility | |
| 175. |
Optical fibers for communication use are mostly fabricated from |
| A. | plastic |
| B. | silica or multicomponent glass |
| C. | ceramics |
| D. | copper |
| Answer» B. silica or multicomponent glass | |
| 176. |
An Si-O bond with a Young’s modulus of 9*1010Nm-1 have an elliptical crack of depth 7nm. The surface energy is 2.29 J. Estimate fracture stress for silica fiber. |
| A. | 4.32*109nm-1 |
| B. | 6.32*109nm-1 |
| C. | 5.2*109nm-1 |
| D. | 3*109nm-1 |
| Answer» A. 4.32*109nm-1 | |
| 177. |
Calculate percentage strain at break for a Si-O bond with a fracture strength of 3.52*1010Nm-1 and Young’s modulus of 9 *109Nm-1. |
| A. | 3.1 % |
| B. | 2.8 % |
| C. | 4.5 % |
| D. | 3.9 % |
| Answer» D. 3.9 % | |
| 178. |
Stress corrosion must be considered while designing and testing optical fiber cables. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 179. |
Which statistics are used for calculations of strengths of optical fibers? |
| A. | edwin statistics |
| B. | newton statistics |
| C. | wei-bull statistics |
| D. | gamma statistics |
| Answer» C. wei-bull statistics | |
| 180. |
. ____________ results from small lateral forces exerted on the fiber during the cabling process. |
| A. | attenuation |
| B. | micro-bending |
| C. | dispersion |
| D. | stimulated emission |
| Answer» B. micro-bending | |
| 181. |
Microscopic meandering of the fiber core axis that is micro-bending is caused due to |
| A. | environmental effects |
| B. | rough edges of the fiber |
| C. | large diameter of core |
| D. | polarization |
| Answer» A. environmental effects | |
| 182. |
How many forms of modal power distribution are considered? |
| A. | one |
| B. | two |
| C. | three |
| D. | four |
| Answer» B. two | |
| 183. |
What does micro-bending losses depend on? |
| A. | core material |
| B. | refractive index |
| C. | diameter |
| D. | mode and wavelength |
| Answer» D. mode and wavelength | |
| 184. |
The fiber should be________________ to avoid deterioration of the optical transmission characteristics resulting from mode-coupling-induced micro-bending. |
| A. | free from irregular external pressure |
| B. | coupled with plastic |
| C. | large in diameter |
| D. | smooth and in a steady state |
| Answer» A. free from irregular external pressure | |
| 185. |
The diffusion of hydrogen into optical fiber affects the ______________ |
| A. | transmission of optical light in the fiber |
| B. | spectral attenuation characteristics of the fiber |
| C. | core of the fiber |
| D. | cladding of the fiber |
| Answer» B. spectral attenuation characteristics of the fiber | |
| 186. |
__________ can induce a considerable amount of attenuation in optical fibers. |
| A. | micro-bending |
| B. | dispersion |
| C. | diffusion of hydrogen |
| D. | radiation exposure |
| Answer» D. radiation exposure | |
| 187. |
The radiation-induced attenuation can be reduced through photo-bleaching. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 188. |
The losses due to hydrogen absorption and reaction with fiber deposits can be temporary. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 189. |
The losses caused due to hydrogen absorption mechanisms are in the range of |
| A. | 20 db/km to25 db/km |
| B. | 10 db/km to15 db/km |
| C. | 25 db/km to50 db/km |
| D. | 0 db/km to5 db/km |
| Answer» C. 25 db/km to50 db/km | |
| 190. |
The cable must be designed such that the strain on the fiber in the cable does not exceed__________ |
| A. | 0.002% |
| B. | 0.01% |
| C. | 0.2% |
| D. | 0.160% |
| Answer» C. 0.2% | |
| 191. |
How many categories exists in case of cable design? |
| A. | two |
| B. | three |
| C. | one |
| D. | four |
| Answer» B. three | |
| 192. |
How many types of buffer jackets are used in fiber buffering? |
| A. | three |
| B. | one |
| C. | two |
| D. | four |
| Answer» A. three | |
| 193. |
Loose tube buffer jackets exhibits a low resistance to movement of the fiber. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 194. |
An inclusion of one or more structural members in an optical fiber so as to serve as a cable core foundation around which the buffer fibers may be wrapped is called _____________ |
| A. | attenuation |
| B. | splicing |
| C. | buffering |
| D. | stranding |
| Answer» D. stranding | |
| 195. |
Which of the following is not a strength member used in optical cable? |
| A. | steel wire |
| B. | germanium |
| C. | aramid yarns |
| D. | glass elements |
| Answer» B. germanium | |
| 196. |
When the stranding approach consists of individual elements (e.g. single-fiber or multi fiber loose tube buffer) than the cable is termed as |
| A. | optical unit cable |
| B. | coaxial cable |
| C. | layer cable |
| D. | bare glass cable |
| Answer» C. layer cable | |
| 197. |
The primary function of the structural member is load bearing. State whether the given statement is true or false. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 198. |
What is the Young’s modulus of Kevlar, an aromatic polyester? |
| A. | 9 ×1010nm-2 |
| B. | 10 ×1010nm-2 |
| C. | 12 ×1010nm-2 |
| D. | 13 ×1010nm-2 |
| Answer» D. 13 ×1010nm-2 | |
| 199. |
The cable is normally covered with an outer plastic sheath to reduce _______________ |
| A. | abrasion |
| B. | armor |
| C. | friction |
| D. | dispersion |
| Answer» A. abrasion | |
| 200. |
A measure of amount of optical fiber emitted from source that can be coupled into a fiber is termed as |
| A. | radiance |
| B. | angular power distribution |
| C. | coupling efficiency |
| D. | power-launching |
| Answer» C. coupling efficiency | |
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