This is the Multiple Choice Questions in Chapter 15: Broadband Communications Systems 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. Broadband long-distance communications were made possible by the advent of
- a. telegraph cables
- b. repeater amplifiers
- c. HF radi
- d. Geostationary satellites
2. A scheme in which several channels are interleaved and then transmitted together is known as
- a. frequency-division multiplex
- b. time-division multiplex
- c. a group
- d. a supergroup
3. A basic group B
- a. occupies the frequency range from 60 to 108 kHz
- b. consists of erect channels only
- c. is formed at the group translating equipment
- d. consists of five supergroups
4. Time-division multiplex
- a. can be used with PCM only
- b. combines five groups into a supergroup
- c. stacks 24 channels in adjacent frequency slots
- d. interleaves pulses belonging to different transmissions
5. The number of repeaters along a coaxial cable link depends on
- a. whether separate tubes are used for the two directions of transmission
- b. the bandwidth of the system
- c. the number of coaxial cables in the tube
- d. the separation of the equalizers
6. A supergroup pilot is
- a. applied at each multiplexing bay
- b. used to regulate the gain of individual repeaters
- c. applied at each adjustable equalizer
- d. fed in at a GTE
7. Microwave link repeaters are typically 50 km apart
- a. because of atmospheric attenuation
- b. because of output tube power limitations
- c. because of the Earth’s curvature
- d. to ensure that the applied dc voltage is not excessive
8. Microwave links are generally preferred to coaxial cable for television transmission because
- a. they have less overall phase distortion
- b. they are cheaper
- c. of their greater bandwidths
- d. of their relative immunity to impulse noise
9. Armored submarine cable is used
- a. to protect the cable at great depths
- b. to prevent inadvertent ploughing-in of the cable
- c. for the shallow shore ends of the cable
- d. to prevent insulation breakdown from the high feed voltages
10. A submarine cable repeater contains, among other equipment,
- a. a dc power supply and regulator
- b. filters for the two directions of transmission
- c. multiplexing and demultiplexing equipment
- d. pilot injected pilot extract equipment
11. A geostationary satellite
- a. is motionless in space (except for its spin)
- b. is not really stationary at all, but orbits the Earth within a 24-hr period
- c. appears stationary over the Earth’s magnetic pole
- d. is located at a height of 35,800 km to ensure global coverage
12. Indicate the correct statement regarding satellite communications.
- a. If two earth stations do not face a common satellite, they should communicate via a double-satellite hop.
- b. Satellites are allocated so that it is impossible for two earth stations not to face the same satellite
- c. Collocated earth stations are used for frequency diversity
- d. A satellite earth station must have as many receive chains as there are carriers transmitted to it
13. Satellite used for intercontinental communications are known as
- a. Comsat
- b. Domsat
- c. Marisat
- d. Intelsat
14. Identical telephone numbers in different parts of a country are distinguished by their
- a. language digits
- b. access digits
- c. area codes
- d. central office codes
15. Telephone traffic is measured
- a. with echo cancellers
- b. by the relative congestion
- c. in terms of the grade of service
- d. in erlangs
16. In order to separate channels in a TDMreceiver, it is necessary to use
- a. AND gates
- b. bandpass filters
- c. differentiation
- d. integration
17. To separate channels in an FDM receiver, it is necessary to use
- a. AND gates
- b. bandpass filters
- c. differentiation
- d. integration
18. Higher order TDM levels are obtained by
- a. dividing pulse widths
- b. using the a-law
- c. using the µ-law
- d. forming supermastergroups
19. Losses in optical fibers can be caused by (indicate the false statement)
- a. impurities
- b. microbending
- c. attenuation in the glass
- d. stepped index operation
20. The 1.55 µm “window” is not yet in use with fiber optic systems because
- a. the attenuation is higher than at 0.85 µm
- b. the attenuation is higher that at 1.3 µm
- c. suitable laser devices have not yet been developed
- d. it does not lend itself to wave
21. Indicate which of the following is nota submarine cable
- a. TAT-7
- b. INTELSAT V
- c. ATLANTIS
- d. CANTAT 2
22. Indicate which of the following is an American domsat system
- a. INTELSAT
- b. COMSAT
- c. TELSTAR
- d. INMARSAT
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