Optical Communication — Part 1 MCQs with Explanations

Dispersion-flattened single mode fiber is the correct answer to “The fibers which relax the spectral requirements for optical sources and allow flexible wavelength division multiplying are known as . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Holey fibers is the correct answer to “Photonic crystal fibers also called as . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Effective R-I and core geometry is the correct answer to “An optical fiber behaves as a birefringence medium due to differences in . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

True is the correct answer to “Any amount of stress occurring at the core-cladding interface would be reduced by grading the material composition.”. This question is standard in competitive examination syllabi for Optical Communication.

10.1μm is the correct answer to “A single mode fiber has mode field diameter 10.2μm and V = 2.20. What is the core diameter of this fiber”. This question is standard in competitive examination syllabi for Optical Communication.

Transverse plane of fiber is the correct answer to “The periodic arrangement of cladding air holes in photonic band gap fibers provides for the formation of a photonic band gap in the . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

0.6 seconds is the correct answer to “A polarization maintaining fiber operates at a wavelength 1.2μm and have a modal birefringence of 1.8 * 10 -3 . Calculate the period of perturbation.”. This question is standard in competitive examination syllabi for Optical Communication.

Stimulated Raman Scattering is the correct answer to “Which of the following is not related to Kerr effects”. This question is standard in competitive examination syllabi for Optical Communication.

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

Wavelength is the correct answer to “In waveguide dispersion, refractive index is independent of . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

34 mm is the correct answer to “A single mode fiber has refractive indices n1=1.50, n2 = 2.23, core diameter of 8μ m , wavelength = 1.5μ m cutoff wavelength = 1.214μ m . Find the radius of curvature”. This question is standard in competitive examination syllabi for Optical Communication.

1.18 W is the correct answer to “0.4 dB/km, 1.4μm, 6μm, 550MHz. Find threshold optical power for stimulated Raman scattering.”. This question is standard in competitive examination syllabi for Optical Communication.

-3.76psnm-1 km-1 is the correct answer to “A single mode fiber has a zero dispersion wavelength of 1.21μm and a dispersion slope of 0.08 psnm -2 km -1 . What is the total first order dispersion at wavelength 1.26μm.”. This question is standard in competitive examination syllabi for Optical Communication.

Elastic is the correct answer to “Linear scattering effects are . . . . . . . . in nature.”. This question is standard in competitive examination syllabi for Optical Communication.

False is the correct answer to “For many applications that involve optical fiber transmission, an intensity modulation optical source is not required.”. This question is standard in competitive examination syllabi for Optical Communication.

Peterman equations is the correct answer to “Which equation is used to calculate MFD”. This question is standard in competitive examination syllabi for Optical Communication.

Soliton propagation is the correct answer to “. . . . . . . . results from a case of 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.”. This question is standard in competitive examination syllabi for Optical Communication.

Phase propagation constant is the correct answer to “When λ is the optical wavelength in vacuum, k is given by $$k = \frac{{2\pi }}{\lambda }.$$ What does k stand for in the”. This question is standard in competitive examination syllabi for Optical Communication.

1.3 and 1.6μm is the correct answer to “An alternative modification of the dispersion characteristics of single mode fibers involves achievement of low dispersion gap over the low-loss wavelength region between . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

False is the correct answer to “Digital transmission is more likely to be affected by modal noise.”. This question is standard in competitive examination syllabi for Optical Communication.

True is the correct answer to “Most of the optical power is carried out in core region than in cladding.”. This question is standard in competitive examination syllabi for Optical Communication.

Meridional is the correct answer to “The . . . . . . . . . ray passes through the axis of the fiber core.”. This question is standard in competitive examination syllabi for Optical Communication.

Multimode fiber is advantageous is the correct answer to “For lower bandwidth applications . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

16.98dB is the correct answer to “If the input power 100μW is launched into 6 km of fiber, the mean optical power at the fiber output is 2μW. What is the overall signal attenuation through the fiber assuming there are no connectors or splices”. This question is standard in competitive examination syllabi for Optical Communication.

Suitable choice of core and cladding components is the correct answer to “The effects of intrinsic absorption can be minimized by”. This question is standard in competitive examination syllabi for Optical Communication.

Attenuation is the correct answer to “The optical fiber incurs a loss in signal power as light travels down the fiber which is called as . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Frequency is the correct answer to “When a ray of light enters one medium from another medium, which quality will not change”. This question is standard in competitive examination syllabi for Optical Communication.

False is the correct answer to “The maximum bit rate that may be obtained on an optical fiber link is 1/3Γ.”. This question is standard in competitive examination syllabi for Optical Communication.

Overlapping but distinguishable pulses is the correct answer to “What is different in case of cross-phase modulation from self-phase modulation”. This question is standard in competitive examination syllabi for Optical Communication.

True is the correct answer to “Plastic fibers are less widely used than glass fibers.”. This question is standard in competitive examination syllabi for Optical Communication.

LED's and Lasers is the correct answer to “The light sources used in fibre optics communication are . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

Si is the correct answer to “Which of the following is not a metallic impurity found in glass in extrinsic absorption”. This question is standard in competitive examination syllabi for Optical Communication.

Broadening of transmitted light pulses along the channel is the correct answer to “What is dispersion in optical fiber communication”. This question is standard in competitive examination syllabi for Optical Communication.

1.214μm is the correct answer to “A step-index fiber has core refractive index 1.46 and radius 4.5μm. Find the cutoff wavelength to exhibit single mode operation. Use relative index difference as 0.25%.”. This question is standard in competitive examination syllabi for Optical Communication.

Total internal reflection is the correct answer to “The phenomenon which occurs when an incident wave strikes an interface at an angle greater than the critical angle with respect to the normal to the surface is called as . . . . . . . .”. This question is standard in competitive examination syllabi for Optical Communication.

2 πm is the correct answer to “Constructive interference occur when total phase change after two successive reflections at upper and lower interfaces is equal to? (Where m is integer)”. This question is standard in competitive examination syllabi for Optical Communication.

Low in single mode and considerable in multimode fiber is the correct answer to “One of the given statements is true for intermodal dispersion. Choose the right one.”. This question is standard in competitive examination syllabi for Optical Communication.

0.06μsec is the correct answer to “Consider a single mode fiber having core refractive index n1 = 1.5. The fiber length is 12m. Find the time taken by the axial ray to travel along the fiber.”. This question is standard in competitive examination syllabi for Optical Communication.

True is the correct answer to “A single-mode step-index fiber or multimode step-index fiber allows propagation of only one transverse electromagnetic wave.”. This question is standard in competitive examination syllabi for Optical Communication.

True is the correct answer to “Numerical aperture is constant in case of step index fiber.”. This question is standard in competitive examination syllabi for Optical Communication.