Description : A dielectric waveguide for the propagation of electromagnetic energy at light frequencies ∙ a. Stripline ∙ b. Microstrip ∙ c. Laser beam ∙ d. Fiber optics
Last Answer : d. Fiber optics
Description : When electromagnetic wave are propagated through a waveguide, they A. are reflected from the walls but do not travel along them B. travel along all four walls of the waveguide C. travel along the broader walls of the guide D. travel through the dielectric without touching the walls
Last Answer : A. are reflected from the walls but do not travel along them
Description : Proposed the use of clad glass fiber as a dielectric waveguide a. Karpon and Keck b. Karpon and Bockham c. Bockham and Kao d. Kao and Keck
Last Answer : c. Bockham and Kao
Description : Proposed the use of a clad glass fiber as a dielectric waveguide. A. Kao and Keck B. Karpon and Keck C. Karpon and Bockham D. Bockham and Kao
Last Answer : D. Bockham and Kao
Description : Which of the following is used as an optical receiver in fiber optics communications a. APD b. Tunnel diode c. Laser diode d. LED
Last Answer : a. APD
Description : ________ generates light beam at a specific visible frequency. A. Glass fiber B. Infrared C. Light waves D. Laser
Last Answer : D. Laser
Description : An example for lossless propagation is a) Dielectric waveguide propagation b) Conductor propagation c) Cavity resonator propagation d) It is not possible
Last Answer : d) It is not possible
Description : Loss due to the diffraction of light when it strikes on the irregularities formed during the manufacturing process of the fiber optics. A. Absorption loss B. Attenuation C. Bending loss D. Rayleigh scattering loss
Last Answer : D. Rayleigh scattering loss
Description : A device that reduces the intensity of light in fiber optics communication systems. A. Reducer B. Quality factor C. Optical attenuator D. Compressor
Last Answer : C. Optical attenuator
Description : Best reason for pressurizing waveguides with dry air A. To maintain propagation B. To maintain temperature of the waveguide C. To reduce the possibility of internal arcing D. To increase the speed of propagation
Last Answer : C. To reduce the possibility of internal arcing
Description : Propagation mode of microwave in a waveguide is known as _______. A. TM B. TE C. SW D. TEM
Last Answer : B. TE
Description : What device in a waveguide system used for stopping or diverting electromagnetic wave as desired? A. Mechanical switch B. Electric switch C. Push-button switch D. Waveguide switch
Last Answer : D. Waveguide switch
Description : What is the insertion loss of connector-type splices for a single mode fiber optics? a. 0.51dB b. 0.31dB c. 0.49dB d. 0.38dB
Last Answer : d. 0.38dB
Description : What is the average insertion loss of fusion splice in fiber optics? a. 0.09dB b. 0.9dB c. 0.19dB d. 0.009dB
Last Answer : a. 0.09dB
Description : One of the following is among the types of fiber optics used in electronics communication. A. Step-index multimode B. Graded-index multimode C. Semi-graded multimode D. Single mode
Last Answer : C. Semi-graded multimode
Description : Circuit used to amplify the optical signal in fiber optics communications links. A. Attenuator B. Optical repeater C. Optical amplifier D. Generator
Last Answer : B. Optical repeater
Description : Fiber optics posses following properties __________ a) Immune electromagnetic interference b) Very less signal attenuation c) Very hard to tap d) All of the mentioned
Last Answer : d) All of the mentioned
Description : In fiber optics, higher-order mode refers to ∙ a. Cladding boundary at high angle ∙ b. Backscattering electromagnetic signals ∙ c. Diffracting signals ∙ d. All of these
Last Answer : ∙ a. Cladding boundary at high angle
Description : Referred to the dielectric constant of a transmission line material. A. Inductance and capacitance B. Velocity factor C. Characteristic impedance D. Propagation velocity
Last Answer : B. Velocity factor
Description : What device measures the angle between two radio frequencies and also the direction of propagation of a wave? A. Densimeter B. Absorption wavemeter C. Goniometer D. Ergometer
Last Answer : C. Goniometer
Description : What is the mixing process? A. Distortion caused by auroral propagation B. The combination of two signals to produce sum and difference frequencies. C. The elimination of noise in wideband receiver by phase differentiation D. The elimination of noise in a wideband receiver by phase comparison
Last Answer : B. The combination of two signals to produce sum and difference frequencies.
Description : Dispersion is used to describe the a. Splitting of white light into its component colors b. Propagation of light in straight lines c. Bending of a beam of light when it goes from one medium to another d. Bending of a beam light when it strikes a mirror
Last Answer : a. Splitting of white light into its component colors
Description : ________ dispersion is caused by the difference in the propagation times of light rays that take different paths down a fiber. a. Material dispersion b. Wavelength dispersion c. Modal dispersion d. Delay dispersion
Last Answer : c. Modal dispersion
Description : ECE Board Exam November 1996 The loss in signal power as light travels down a fiber is A. attenuation B. propagation C. absorption D. scattering
Last Answer : A. attenuation
Description : Which of the following statements is not true with respect to microwaves? (A) Electromagnetic waves with frequencies from 300 GHz to 400 THz. (B) Propagation is line-of-sight. (C) Very ... waves cannot penetrate walls. (D) Use of certain portions of the band requires permission from authorities.
Last Answer : (A) Electromagnetic waves with frequencies from 300 GHz to 400 THz.
Description : Which of the following is used as an optical receiver in fiber optics communications ∙ a. APD ∙ b. Tunnel diode ∙ c. Laser diode ∙ d. LED
Description : Electromagnetic waves of frequencies arbitrarily lower than 3,000 GHz, propagated in space without artificial guide. A. Space waves B. Terrestrial waves C. Mobile D. Hertzian waves
Last Answer : D. Hertzian waves
Description : The mode theory uses electromagnetic wave behavior to describe the propagation of the light along the fiber. What is a set of guided electromagnetic waves called?
Last Answer : Modes of the fiber.
Description : The first laser emitted a. Pulses of 694 nm red light b. A continuous red beam c. Pulses of white light from a helical flashlamp d. Spontaneous emission
Last Answer : a. Pulses of 694 nm red light
Description : What generates a light beam of a specific visible frequency? a. Laser b. Maser c. Infrared d. Flashlight
Last Answer : a. Laser
Description : Most mobile satellite array uses ___________ in transforming 50 to 150 Ω impedance. A. stub B. balun C. quarter-wavelength transformer D. microstrip tapers.
Last Answer : C. quarter-wavelength transformer
Description : What do you call a cable consisting of twisted pairs of conductors, each separately insulated? A. Microstrip line B. Strip line C. Quad D. Coaxial cable
Last Answer : C. Quad
Description : A single conductor running from the transmitter to the antenna. A. RG-8/U B. Single line wire C. Twin-lead D. MIcrostrip
Last Answer : B. Single line wire
Description : An electromagnetic wave is ________ polarized when the electric field lies wholly in one plane containing the direction of propagation. A. Horizontally B. Linearly C. Circularly D. Vertically
Last Answer : B. Linearly
Description : Fiber optic cables operate at frequencies near a. 20MHz b. 200MHz c. 2GHz d. 800THz
Last Answer : d. 800THz
Description : Fiber optic cable operates near _______ frequencies. A. 800 THz B. 20 MHz C. 200 MHz D. 2 GHz
Last Answer : A. 800 THz
Description : The size, shape, and dielectric material of a waveguide must be constant throughout its length for energy to move from one end to the other without reflections. What could be the effect in any abrupt change in its size or shape?
Last Answer : Reflections.
Description : What is the result of an abrupt change in the size, shape, or dielectric of a waveguide?
Description : Why are visible-light LEDs not used for fiber optics? ∙ a. It has high losses ∙ b. It has short wave ∙ c. It has low attenuation ∙ d. It has weak signal
Last Answer : ∙ a. It has high losses
Description : The following are the cause of light attenuation in fiber optics except ∙ a. Backscattering ∙ b. Absorption ∙ c. Refraction ∙ d. Microbends
Last Answer : c. Refraction
Description : In order for fiber optics to work, the incident light inside the fiber must hit the wall of the fiber at: w) 90 degrees x) 45 degrees y) an angle greater than the critical angle z) none of the above
Last Answer : ANSWER: Y -- AN ANGLE GREATER THAN THE CRITICAL ANGLE
Description : Fiber optics cable used in communication, works on the principle of (1) regular reflection of light (2) diffuse reflection of light (3) refraction of light (4) total internal reflection of light
Last Answer : total internal reflection of light
Description : Any energy which radiates in the form of radio waves, infrared waves, light waves, x-rays, etc. A. Radiant energy B. Electromagnetic C. Heat D. Ultraviolet
Last Answer : B. Electromagnetic
Description : The ratio of speed of light in air to the speed of light in another substance is called the a. Speed factor b. Index of reflection c. Index of refraction d. Dielectric constant
Last Answer : c. Index of refraction
Description : Any small element of space in the path of a wave may be considered as a source of secondary wavelet. A. De Morgan’s Principle B. Faraday’s Law C. Huygen’s Principle D. Fresnel’s Law of optics
Last Answer : C. Huygen’s Principle
Description : Which of the following antennas is best excited from a waveguide? A. Biconical B. Horn C. Helical D. Discone
Last Answer : B. Horn
Description : A waveguide passive component that brings a smooth change in the direction of axis maintained perpendicular to the plane of polarization? A. L bend B. H bend C. T bend D. X bend
Last Answer : B. H bend
Description : Which of the following is not a bounded medium? A. Coaxial line B. Two-wire line C. Waveguide D. Free space
Last Answer : D. Free space
Description : The advantage of periscope antenna in microwave A. Minimize interference to and from other neighboring stations B. Shorten waveguide link C. Reduce tower height D. All of these
Last Answer : B. Shorten waveguide link