Optical Communication — Part 2 MCQs with Explanations

0.27 is the correct answer to “What is the numerical aperture of the fiber if the angle of acceptance is 16 degree”. This question is standard in competitive examination syllabi for Optical Communication.

False is the correct answer to “Rayleigh scattering can be reduced by operating at smallest possible wavelengths.”. This question is standard in competitive examination syllabi for Optical Communication.

Pulse broadening at output is the correct answer to “Intermodal dispersion occurring in a large amount in multimode step index fiber results in . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

18.84 is the correct answer to “A graded-index fiber has a core with parabolic refractive index profile of diameter of 30μm, NA=0.2, λ=1μm. Estimate the normalised frequency.”. This question is standard in competitive examination syllabi for Optical Communication.

40.5psnm-1 km-1 is the correct answer to “The dispersion due to material, waveguide and profile are -2.8nm -1 km -1 , 20.1nm -1 km -1 and 23.2nm -1 km -1 respectively. Find the total first order dispersion”. This question is standard in competitive examination syllabi for Optical Communication.

1ns/km is the correct answer to “When two components are equally excited at the fiber input, then for polarization maintaining fibers δΓg should be around . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Larger than is the correct answer to “3dB optical bandwidth is always . . . . . . . the 3dB electrical bandwidth.”. This question is standard in competitive examination syllabi for Optical Communication.

Geometric distribution of light in a propagating mode is the correct answer to “What is needed to predict the performance characteristics of single mode fibers”. This question is standard in competitive examination syllabi for Optical Communication.

1 × 10-5 is the correct answer to “The beat length in a single mode optical fiber is 8 cm when light from a laser with a peak wavelength 0.6μm is launched into it. Estimate the modal birefringence.”. This question is standard in competitive examination syllabi for Optical Communication.

Fiber birefringence is the correct answer to “The difference between the modes' refractive indices is called as . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Less than 1μm is the correct answer to “The high index contrast enables the PCF core to be reduced from around 8 μmin conventional fiber to . . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Missing molecules, oxygen defects in glass is the correct answer to “Absorption losses due to atomic defects mainly include . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

$$\delta f > > \frac{1}{{\delta T}}$$ is the correct answer to “The modal noise occurs when uncorrected source frequency is”. This question is standard in competitive examination syllabi for Optical Communication.

Yes is the correct answer to “An optical fiber has a core radius 2μm and a numerical aperture of 0.1. Will this fiber operate at single mode at 600 nm”. This question is standard in competitive examination syllabi for Optical Communication.

Helical path is the correct answer to “Skew rays follow a . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

7.69ns/km is the correct answer to “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”. This question is standard in competitive examination syllabi for Optical Communication.

Photodiodes is the correct answer to “The optical source used for detection of optical signal is . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

0.77 nm is the correct answer to “The optical source used in a fiber is an injection laser with a relative spectral width $$\frac{{{\sigma _\lambda }}}{\lambda }$$ of 0.0011 at a wavelength of 0.70μm. Estimate the RMS spectral width.”. This question is standard in competitive examination syllabi for Optical Communication.

Propagation constant is the correct answer to “$${\Gamma _g} = \frac{{d\beta }}{{{C^ * }dk}}.$$ What is β in the given equation”. This question is standard in competitive examination syllabi for Optical Communication.

Modal noise is the correct answer to “Disturbance along the fiber such as vibrations, discontinuities, connectors, splices, source/detectors coupling result in . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

0.2 to 1 ns/km is the correct answer to “Practical pulse broadening value for graded index fiber lies in the range of . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

False is the correct answer to “The nonlinear effects in optical fibers are large.”. This question is standard in competitive examination syllabi for Optical Communication.

Forward direction is the correct answer to “Mie scattering has in-homogeneities mainly in . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Bending of light waves is the correct answer to “What is refraction”. This question is standard in competitive examination syllabi for Optical Communication.

Two is the correct answer to “How many propagation modes are present in single mode fibers”. This question is standard in competitive examination syllabi for Optical Communication.

True is the correct answer to “Self-phase modulation causes modifications to the pulse spectrum.”. This question is standard in competitive examination syllabi for Optical Communication.

Linear scattering losses is the correct answer to “Rayleigh scattering and Mie scattering are the types of . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Kerr effects is the correct answer to “Nonlinear effects which are defined by the intensity - dependent refractive index of the fiber are called as . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Group velocity is the correct answer to “Which is the most important velocity in the study of transmission characteristics of optical fiber”. This question is standard in competitive examination syllabi for Optical Communication.

False is the correct answer to “Most of the power in an optical fiber is transmitted in fiber cladding.”. This question is standard in competitive examination syllabi for Optical Communication.

2dB/km is the correct answer to “When the input and output power in an optical fiber is 120μW & 3μW respectively and the length of the fiber is 8 km. What is the signal attenuation per km for the fiber”. This question is standard in competitive examination syllabi for Optical Communication.

It is a dimensionless quantity is the correct answer to “What is the unit of normalized frequency”. This question is standard in competitive examination syllabi for Optical Communication.

Inter-symbol interference is the correct answer to “What does ISI stand for in optical fiber communication”. This question is standard in competitive examination syllabi for Optical Communication.

Law of refraction (Snell's Law) is the correct answer to “Which law gives the relationship between refractive index of the dielectric”. This question is standard in competitive examination syllabi for Optical Communication.

Negative-dispersion fiber is the correct answer to “The variant of non-zero-dispersion-shifted fiber is called as . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Pulsed is the correct answer to “. . . . . . . . zsemiconductor laser sources generally have broader bandwidths.”. This question is standard in competitive examination syllabi for Optical Communication.

A loss mechanism related to the material composition and fabrication of fiber is the correct answer to “Which of the following statements best explain the concept of material absorption”. This question is standard in competitive examination syllabi for Optical Communication.

Three is the correct answer to “How many mechanisms are there which causes absorption”. This question is standard in competitive examination syllabi for Optical Communication.

Radiation attenuation coefficients is the correct answer to “In the given equation, state what αr suggests”. This question is standard in competitive examination syllabi for Optical Communication.

Less than the reciprocal of broadened pulse duration is the correct answer to “For no overlapping of light pulses down on an optical fiber link, the digital bit rate BT must be . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.