# Kennedy: MCQs in Introduction to Fiber Optic Technology

(Last Updated On: December 8, 2017)

This is the Multiple Choice Questions in Chapter 18: Introduction to Fiber Optic Technology from the book Electronic Communication Systems by George Kennedy. If you are looking for a reviewer in Communications Engineering this will definitely help. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. Make sure to familiarize each and every questions to increase the chance of passing the ECE Board Exam.

### Start Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. What is the frequency limit of copper wire?

• a. approximately 0.5 MHz
• b. approximately 1.0 MHz
• c. approximately 40 GHz
• d. None of the above

2. Approximately what is the frequency limit of the optical fiber?

• a. 20 GHz
• b. 1 MHz
• c. 100 MHz
• d. 40 MHz

3. A single fiber can handle as many voice channel as

• a. a pair of copper conductors
• b. a 1500-pair cable
• c. a 500-pair cable
• d. a 1000-pair cable

4. An incident ray can be defined as

• a. a light ray reflected from a flat surface
• b. a light ray directed toward a surface
• c. a diffused light ray
• d. a light ray that happens periodically

5. The term dispersion describes the process of

• a. separating light into its component frequencies
• b. reflecting light from a smooth surface
• c. the process by which light is absorbed by an uneven rough surface
• d. light scattering

6. Which of the following terms describes the reason that light is refracted at different angles?

• a. Photon energy changes with wavelength
• b. Light is refracted as a function of surface smoothness
• c. The angle is determined partly by a and b
• d. The angle is determined by the index of the materials

7. The term critical angle describes

• a. the point at which light is refracted
• b. the point at which light becomes invisible
• c. the point at which light has gone from the refractive mode to the reflective mode
• d. the point at which light has crossed the boundary layers from one index to another

8. The cladding which surrounds the fiber core

• a. is used to reduce optical interference
• b. is used to protect the fiber
• c. acts to help guide the light in the core
• d. ensures that the refractive index remains constant

9. The reflective index number is

• a. a number which compares the transparency of a material with that of air
• b. a number assigned by the manufacturer to the fiber in question
• c. a number which determines the core diameter
• d. a term for describing core elasticity

10. The terms single mode and multimode are best describes as

• a. the number of fibers placed into a fiber-optic cable
• b. the number of voice channels each fiber can support
• c. the number of wavelengths each fiber can support
• d. the index number

11. The higher the index number

• a. the higher the speed of light
• b. the lower the speed of light
• c. has no effect on the speed of light
• d. the shorter the wavelength propagation

12. The three major groups in the optical system are

• a. the components, the data rate and response time
• c. the transmitter, the cable, and the receiver
• d. the source, the link, and the detector

13. As light is coupled in a multipoint reflective device, the power is reduced by

• a. 1.5 dB
• b. 0.1 dB
• c. 0.5 dB
• d. 0.001 dB

14. When connector losses, splice losses, and coupler losses are added, what is the final limiting factor?

• a. Source power
• b. Fiber attenuation
• c. Connector and splice losses
• d. Detector sensitivity

15. The term responsivity as it applies to a light detector is best described as

• a. the time required for the signal to go from 10 to 90 percent of maximum amplitude
• b. the ratio of the diode output current to optical input power
• c. the ratio of output current to output power
• d. the ratio of output current to input current

16. Loss comparisons between fusion splices and mechanical splices are

• a. 1:10
• b. 10:1
• c. 20:1
• d. 1:20

17. The mechanical splice is best suited for

• a. quicker installation under ideal conditions
• b. minimum attenuation losses
• c. field service conditions
• d. situations in which cost of equipment is not a factor

18. EMD is best describe by which statement?

• a. 70 percent of the core diameter and 70% of the fiber NA should be filled with light
• b. 70 percent of the fiber diameter and 70% of the cone of acceptance should be filled with light
• c. 70 percent of input light should be measured at the output
• d. 70 percent of the unwanted wavelengths should be attenuated by the fiber

19. Which of the following cables will have the highest launch power capability?

• a. 50/125/0.2
• b. 85/125/0.275
• c. 62.5/125/0.275
• d. 100/140/0.3

20. The term power budgeting refers to

• a. the cost of cables, connectors, equipment, and installation
• b. the loss of power due to defective components
• c. the total power available minus the attenuation losses
• d. the comparative costs of fiber and copper installations