MCQs in Fiber Optics Communications Part I

(Last Updated On: September 10, 2019)

MCQs in Fiber Optics Communications - Part I

This is the Multiples Choice Questions Part 1 of the Series in Fiber Optics Communications as one of the Communications Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies, Communications Books, Journals and other Communications References.

Online Questions and Answers Topic Outline

  • MCQs in Principles of Light Transmission
  • MCQs in Types of Light Sources, Laser, LED
  • MCQs in Light Detectors
  • MCQs in Modulation and Waveform
  • MCQs in System Design
  • MCQs in General application
  • MCQs in System Bandwidth
  • MCQs in Splicing Techniques

MCQs in Fiber Optics Communications Series

Following is the list of multiple choice questions in this brand new series:

Optical Fiber Communications MCQs
PART 1: MCQs from Number 1 – 50                        Answer key: PART I
PART 2: MCQs from Number 51 – 100                   Answer key: PART II
PART 3: MCQs from Number 101 – 150                 Answer key: PART III
PART 4: MCQs from Number 151 – 200                 Answer key: PART IV
PART 5: MCQs from Number 201 – 250                 Answer key: PART V
PART 6: MCQs from Number 251 – 300                 Answer key: PART VI

Start Practice Exam Test Questions Part I of the Series

1. Founded the wave theory of light

  • a. Francesco Grimaldi
  • b. Edward Appleton
  • c. James Clerk Maxwell
  • d. Christian Huygens

2. 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

3. Developed the first laser

  • a. Charles Townes
  • b. Theodore Maiman
  • c. Gordon McKenzie
  • d. Albert Einstein

4. The band of light wavelengths that are too long to be seen by the human eye

  • a. Amber
  • b. Visible
  • c. Infrared
  • d. Ultraviolet

5. The band of light wavelengths that are too short to be seen by the human eye

  • a. Amber
  • b. Visible
  • c. Infrared
  • d. Ultraviolet

6. Which color has the shortest wavelength of light?

  • a. Red
  • b. Yellow
  • c. Blue
  • d. Green

7. What generates a light beam of a specific visible frequency?

  • a. Laser
  • b. Maser
  • c. Infrared
  • d. Flashlight

8. Which of the following materials is sensitive to light?

  • a. Photoresist
  • b. Photosensitive
  • c. Light Sensitive
  • d. Maser

9. The core of an optical fiber has a

  • a. Lower refracted index than air
  • b. Lower refractive index than the cladding
  • c. Higher refractive index than the cladding
  • d. Similar refractive index with the cladding

10. Is the different angle of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted.

  • a. Acceptance angle
  • b. Modes
  • c. Sensors
  • d. Aperture

11. The loss in signal power as light travels down a fiber is called

  • a. Dispersion
  • b. Scattering
  • c. Absorption
  • d. Attenuation

12. The bandwidth of optical fiber

  • a. 900M Hz
  • b. 900 PHz
  • c. 900 THz
  • d. 900 EHz

13. If a mirror is used to reflect light, the reflected light angle is ____ as the incident angle

  • a. Smaller
  • b. Larger
  • c. The same
  • d. Independent

14. What is a specific path the light takes in an optical fiber corresponding to a certain angle and number of reflection

  • a. Mode
  • b. Grade
  • c. Numerical Aperture
  • d. Dispersion

15. Is the width of the range of wavelengths emitted by the light source

  • a. Bandwidth
  • b. Chromatic Dispersion
  • c. Spectral width
  • d. Beamwidth

16. Which theory states that the light wave behaves as if it consists of many tiny particles?

  • a. Huygen’s theory
  • b. Wave theory of light
  • c. Nyquist theory
  • d. Quantum theory

17. Fiber optic cables operate at frequencies near

  • a. 20 MHz
  • b. 200 MHz
  • c. 2G Hz
  • d. 800 THz

18. When a beam of light enters one medium from another, which quantity will not change?

  • a. Direction
  • b. Speed
  • c. Frequency
  • d. Wavelength

19. 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

20. Luminance efficiency is minimum for a

  • a. Fluorescent tube
  • b. High wattage light bulb
  • c. Mercury vapor lamp
  • d. Low wattage light bulb

21. An object farther from a converging lens than its focal point always has a/an _____ image.

  • a. Inverted
  • b. The same in size
  • c. Virtual
  • d. Smaller size

22. An object nearer to a converging lens than its focal point always has a/an ______ image.

  • a. Inverted
  • b. The same in size
  • c. Virtual
  • d. Smaller size

23. The real image formed by a spherical mirror is ____ relative to its object

  • a. Erect
  • b. Inverted
  • c. Smaller
  • d. Larger

24. The wavelength of light has no role in

  • a. Diffraction
  • b. Interference
  • c. Polarization
  • d. Reflection

25. Longitudinal waves do not exhibit

  • a. Polarization
  • b. Refraction
  • c. Reflection
  • d. Diffraction

26. ________ 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

27. What is the average insertion loss of fusion splice in fiber optics?

  • a. 0.09 dB
  • b. 0.9 dB
  • c. 0.19 dB
  • d. 0.009 dB

28. What is the insertion loss of connector-type splices for a single mode fiber optics?

  • a. 0.51 dB
  • b. 0.31 dB
  • c. 0.49 dB
  • d. 0.38 dB

29. What is the lifetime of LEDs?

  • a. 200,000 minutes
  • b. 200,000 hours
  • c. 150,000 minutes
  • d. 150,000 hours

30. What is the lifetime of ILDs?

  • a. 50,000 hours
  • b. 75,000 hours
  • c. 100,000 hours
  • d. 125,000 hours

31. Photodiodes used as fiber optic directors are

  • a. Unbiased to generate a voltage same as a solar cell
  • b. Forward bias
  • c. Reversed bias
  • d. Thermoelectrically cooled

32. What type of fiber has the highest modal dispersion?

  • a. Step-index multimode
  • b. Graded index multimode
  • c. Step-index single mode
  • d. Graded index mode

33. Laser light is ______ emission.

  • a. Coherent
  • b. Stimulated
  • c. Spontaneous
  • d. Coherent and stimulated

34. A dielectric waveguide for the propagation of electromagnetic energy at light frequencies

  • a. Stripline
  • b. Microstrip
  • c. Laser beam
  • d. Fiber optics

35. Is a non-coherent light source foe optical communications system.

  • a. ILD
  • b. LED
  • c. APD
  • d. PIN Diode

36. Which type of laser is the simplest to modulate directly by changing its excitation?

  • a. Semiconductor
  • b. Ruby
  • c. Helium-neon
  • d. Neodymium-YAG

37. Which laser emits light in the visible range 400 to 700 nm?

  • a. Argon-ion
  • b. Nitrogen
  • c. Carbon-dioxide
  • d. Neodymium-YAG

38. Which is the proper measurement of average power emitted by a pulsed laser?

  • a. Energy x time
  • b. Pulse energy x repetition rate
  • c. Pulse energy / repetition rate
  • d. Peak power x pulse length

39. What is the photon energy for an infrared wave with frequency of 1012 Hz?

  • a. 10.6 x 1034  joules
  • b. 6.63 x 10-34 joules
  • c. 6.63 x 10-22 joules
  • d. 10.6 x 1022 joules

40. A positive lens with a focal length of 10 cm forms a real image of an object 20 am away from the lens. How far is the real image from the lens?

  • a. 5 cm
  • b. 10 cm
  • c. 15 cm
  • d. 20 cm

41. Which of the following factor does not harm laser efficiency?

  • a. Atmospheric absorption
  • b. Excitation energy not absorbed
  • c. Problems in depopulating the lower laser level
  • d. Inefficiency in populating the upper laser level

42. Which of the following contributes to the broadening of laser emission bandwidth?

  • a. Doppler shift of moving atoms and molecules
  • b. Amplification within the laser medium
  • c. Coherence of the laser light
  • d. Optical pumping of the laser transition

43. The first laser emitted

  • a. Pulses of 694 nm red light
  • b. A continuous red beam
  • c. Pulses of white light from a helical flash lamp
  • d. Spontaneous emission

44. What is the stage of the sand becoming a silicon?

  • a. Liquid
  • b. Gas
  • c. Molten
  • d. Hot

45. Which of the following is used as an optical transmitter on the Fiber Optical Communications?

  • a. APD
  • b. LSA diode
  • c. PIN diode
  • d. LED

46. Which of the following is used as an optical receiver in fiber optics communications

  • a. APD
  • b. Tunnel diode
  • c. Laser diode
  • d. LED

47. The numerical aperture of a fiber if the angle of acceptance is 15 degrees, is

  • a. 017
  • b. 0.26
  • c. 0.50
  • d. 0.75

48. The inner portion of the fiber cable is called

  • a. Cladding
  • b. Coating
  • c. Inner conductor
  • d. Core

49. Which type of laser is the simplest to modulate directly by changing its excitation?

  • a. Semiconductor
  • b. Ruby
  • c. Helium-neon
  • d. Neodymium-YAG

50. The laser frequency when the light has the wavelength 800 nm is

  • a. 375 x 1012 Hz
  • b. 475 x 1015 Hz
  • c. 375 x 109 Hz
  • d. 375 x 1018 Hz

Complete List of MCQs in Communications Engineering per topic

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