1) Which line code in PCM indicates the return of signal to zero between each pulse & takes place even due to occurrence of consecutive 0's & 1's in the signal?
a. Return-to-zero (RZ)
b. Non-Return to zero space
c. Return to zero inverted
d. Non-return to zero inverted
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2) In the structure of fiber, the light is guided through the core due to total internal ______
a. reflection
b. refraction
c. diffraction
d. dispersion
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3) In the structure of a fiber, which component provides additional strength and prevents the fiber from any damage?
a. Core
b. Cladding
c. Buffer Coating
d. None of the above
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4) Which is the transmission medium for VLF electromagnetic waves especially applicable for aeronautical and submarine cables?
a. Paired wires
b. Coaxial cable
c. Waveguide
d. Wireless
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5) Which rays exhibit the variation in the light acceptability ability of the fiber?
a. Meridional
b. Skew
c. Leaky
d. All of the above
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6) If a fiber operates at 1400nm with the diameter of about 10 μm, n1 = 1.30, Δ = 0.80% , V = 3.5, then how many modes will it have?
a. 6.125
b. 9.655
c. 12.95
d. 16.55
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7) Which kind of dispersion phenomenon gives rise to pulse spreading in single mode fibers?
a. Intramodal
b. Intermodal
c. Material
d. Group Velocity
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8) With respect to single mode and graded index fibers, which parameter specifies the propagation of polarization modes with different phase velocities & the difference between their effective refractive indices?
a. Mode field diameter
b. Birefringence
c. Fiber beat length
d. Spot Size
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9) On which of the following factor/s do/does the 'Hydrogen Effect' depend/s?
a. Type of fiber & Cable Design
b. Operating Wavelength
c. Installation Method
d. All of the above
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10) Consider the statements given below. Which among them is not a drawback of double crucible method?
a. Utility in mass production of fibers
b. High attenuation
c. High OH content in drawn fiber
d. Addition of impurity while the fiber is drawn
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11) Consider the assertions given below. Which is the correct sequential order of process adopted in glass fiber preparation?
A. Drawing of fiber
B. Production of pure glass
C. Pulling of fiber
D. Conversion of pure glass into preform
a. B, D, A, C
b. A, B, C, D
c. C, A, D, B
d. D, B, A, C
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12) At which level of temperature does the oxidation process occur in MCVD?
a. Low
b. Moderate
c. High
d. Unpredictable
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13) Assuming no ISI, the maximum possible bandwidth of a multimode graded index fiber with 5 MHz, shows the total pulse broadening of 0.1s for the distance of about 12km. What would be the value of bandwidth length product?
a. 40 MHz
b. 60 MHz
c. 90 MHz
d. 120 MHz
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14) In Rayleigh scattering of light in glass, at which type of temperature does the glass attain the state of thermal equilibrium and exhibits its relativity to annealing temperature?
a. Junction
b. Fictive
c. Breakdown
d. Decomposition
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15) Which type of scattering occurs due to interaction of light in a medium with time dependent optical density variations thereby resulting into the change of energy (frequency) & path?
a. Stimulated Brilliouin Scattering (SBS)
b. Stimulated Raman Scattering (SRS)
c. Mie Scattering
d. Rayleigh Scattering
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16) The macroscopic bending losses show an exponential increase due to ________ in radius of curvature.
a. Increase
b. Decrease
c. Stability
d. None of the above
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17) Which type of mechanical splicing exhibits the permanent bonding of prepared fiber ends with the rigid alignment of the tube?
a. Snug Tube Splicing
b. Loose Tube Splicing
c. Elastomeric Splicing
d. Precision Pin Splicing
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18) Which component of fiber-optic connector has a provision of entry for the fiber along with the fixation to connector housing?
a. Ferrule
b. Cable
c. Connector Housing
d. Coupling Device
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19) Which among the following is regarded as a keyed bayonet connector along with its feasibility of easiest insertion and removal from the fiber optic cable?
a. FC Connectors
b. LC Connectors
c. MT-RJ Connectors
d. ST Connectors
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20) How many mating cycles are being rated by typically matched SC Connectors?
a. 500
b. 600
c. 800
d. 1000
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21) In Stimulated Emission, which among the following parameters of generated photon is/are similar to the photon of incident wave?
a. Phase
b. Frequency
c. Polarization & direction of travel
d. All of the above
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22) Consider a crystal of ruby laser whose length is 6 cm and the refractive index is 1.8, emits the wavelength of about 0.55 μm. What will be the value of number of longitudinal modes?
a. 3.9 x 105
b. 4.9 x 105
c. 5.6 x 105
d. 7.7 x 105
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23) In a laser structure, the existence of standing waves is possible at frequencies for which the distance between the mirrors is an integral number of ________
a. λ / 2
b. λ / 4
c. λ / 6
d. λ / 8
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24) The small section of fiber which is coupled to the optical source is known as _________
a. Flylead
b. Pigtail
c. Both a and b
d. None of the above
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25) In Lambertian output pattern of LED, the source is ______ bright from all directions.
a. Less
b. Equally
c. More
d. Unpredictably
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26) In pyroelectric photodetectors, the consequent increase in dielectric constant due to temperature variation by the photon absorption, is generally measured as change in _______
a. resistance
b. inductance
c. admittance
d. capacitance
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27) Which type of preamplifier plays a crucial role in reducing the effect of thermal noise?
a. Low Impedance Pre-amplifier
b. High Impedance Preamplifier
c. Transimpedance Preamplifier
d. None of the above
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28) In high impedance preamplifier, how are the noise sources kept to minimum level?
a. By reducing dark current with proper selection of photodiode
b. By reducing thermal noise of biasing resistor
c. By using high impedance amplifier
d. All of the above
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29) Which among the following are the disadvantages of an optical feedback transimpedance receiver?
A. Increase in receiver input capacitance
B. Increase in dark current
C. Decrease in receiver input capacitance
D. Decrease in dark current
a. A & B
b. C & D
c. A & D
d. B & C
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30) Which category/ies of wavelength division multiplexer comprise/s two 3dB couplers where the splitting of an incident beam takes place into two fiber paths, followed by the recombination with second 3-dB coupler?
a. Interference filter based devices
b. Angular dispersion based devices
c. Mach-Zehnder Interferometers
d. All of the above
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31) Which among the following controls the length of Fabry-Perot interferometer so that it can act as a tunable optical filter?
a. Transducer
b. Tachometer
c. Multimeter
d. Phase-meter
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32) In circulator, an optical path of signal follows _______
a. An open loop
b. A closed loop
c. Both a and b
d. None of the above
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33) Which among the following is/are responsible for generating attenuation of an optical power in fiber?
a. Absorption
b. Scattering
c. Waveguide effect
d. All of the above
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34) Consider the assertions/ characteristics given below. Which type of attenuation measurement technique exhibits these characteristics?
1. Necessity of accessing both ends of fiber.
2. Measurements corresponding to specific wavelengths.
3. Requirement of spectral response over a range of wavelengths.
a. Cutback Technique
b. Insertion Loss Technique
c. Use of OTDR Technique
d. None of the above
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35) For neglecting the pulse dispersion in the digital systems, the rms width of fiber impulse response must be _________one-quarter of the pulse spacing.
a. Less than
b. Equal to
c. Greater than
d. None of the above
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