This is the Multiples Choice Questions Part 1 of the Series in Wire and Wireless Communications System 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 Mobile Communications
- MCQs in Cellular Communication
- MCQs in Trunk Radio
- MCQs in Radio Paging System
- MCQs in Facsimile
- MCQs in Telephone Set
- MCQs in Signaling
- MCQs in Transmission Considerations in long distance network
- MCQs in Insertion Loss
- MCQs in VF Repeaters
- MCQs in Traffic Calculations
- MCQs in Reference Equivalent and Standards
- MCQs in Telephone Networks
- MCQs in Billing
- MCQs in Network Hierarchy and Class type
- MCQs in Connection and Performance of Wire and Wireless Communications
MCQs in Wire and Wireless Communications System Series
Following is the list of multiple choice questions in this brand new series:
Start Practice Exam Test Questions Part I of the Series
1. Typical speech power
- A. 10 to 1000 µW
- B. 100 to 1000 mW
- C. 10 to 1000 nW
- D. 100 to 1000 pW
2. The maximum intelligibility for voice frequency is located between
- A. 250 and 500 Hz
- B. 1000 and 3000 Hz
- C. 500 and 1000 Hz
- D. 3000 and 5000 Hz
3. The maximum voice energy is located between
- A. 250 and 500 Hz
- B. 1000 and 3000 Hz
- C. 500 and 1000 Hz
- D. 3000 and 5000 Hz
4. A device used to measure speech volume.
- A. speech meter
- B. volume meter
- C. volume unit meter
- D. speedometer
5. By definition, for a sine wave
- A. 0 dBm = 0 V.U.
- B. 0 dBW = 0 V.U.
- C. 0 dBa = 0 V.U.
- D. 0 dBf = 0 V.U.
6. Presently, this is the “standard” frequency bandwidth for voice transmission.
- A. 0 to 4000 Hz
- B. 100 to 3400 Hz
- C. 300 to 3400 Hz
- D. 300 to 3000 Hz
7. Which of the following is commonly used wire for subscriber loop design?
- A. AWG # 19
- B. AWG # 18
- C. AWG # 30
- D. AWG # 33
8. The resistance limit for No. 2 Crossbar Exchange (US) is
- A. 1300 Ω
- B. 2000 Ω
- C. 1250 Ω
- D. 1200 Ω
9. AWG # 26 has a typical loss of
- A. 0.21 dB/1000 ft.
- B. 0.32 dB/1000 ft.
- C. 0.41 dB/1000 ft.
- D. 0.51 dB/1000 ft.
10. What is the standard voice channel spacing?
- A. 44 MHz
- B. 40 kHz
- C. 4 kHz
- D. 40 MHz
11. Which tester is used to measure SWR?
- A. Multimeter
- B. Oscilloscope
- C. Spectrum analyzer
- D. Reflectometer
12. What is singing?
- A. The result of intermodulating two or more signals of different frequencies to produce a tone having a frequency equal to the sum of the frequencies of the signals intermodulated.
- B. The result of intermodulating two or more signals of different frequencies to produce a tone having a frequency higher than that of the signal having the highest frequency.
- C. An undesired self-sustained oscillation in a system, generally caused by excessive positive feedback.
- D. An art or form of entertainment that can make one rich.
13. Which stage increases the selectivity of the circuit in an AM receiver?
- A. Detector
- B. IF stage
- C. Modulator
- D. Mixer
14. The ________ of radio receiver amplify weak signal and produce a desirable intelligence at the output speaker.
- A. sensitivity
- B. selectivity
- C. reliability
- D. fidelity
15. Full-duplex transmission means
- A. One-way transmission
- B. 24-hour transmission
- C. Broadcast transmission
- D. Two-way simultaneous transmission
16. What is a multidrop line?
- A. A piece of wire with a thick insulating material that serves to protect the conductive materials from damage in the event the wire is dropped.
- B. A line designed to withstand high pressure.
- C. A line or circuit interconnecting several situations.
- D. A bus line
17. A passive _________ is an electronic device which reduces signal strength by a specified amount in dB.
- A. Splitter
- B. Filter
- C. Trimmer
- D. Attenuator
18. The signal quality of the calls is constantly monitored by the base station, when the quality of the calls drops below a certain specified level. The base request the MTSO to try and find a better cell site.
- A. Hand-off
- B. Cell splitting
- C. Roaming
- D. Frequency reuse
19. A digital identification associated with a cellular system.
- A. SAT
- B. SID
- C. ESN
- D. MIN
20. How many seconds does facsimile transmit a stranded page?
- A. 5
- B. 10
- C. 20
- D. 25
21. A kind of recording used in facsimile.
- A. Electrolytic recording
- B. Electrothermal recording
- C. Electropercussive recording
- D. Electrostatic recording
22. A type of distortion a facsimile produce when it becomes out of synchronization?
- A. Pincushion
- B. Barrel
- C. Skewing
- D. Fattening
23. What is an acoustic coupler?
- A. A device that radiates audible signals via a transmitting antenna
- B. A device that converts electric signals into audio signals, enabling data to be transmitted over the public telephone network via a conventional telephone handset
- C. A device that receives audible signals and retransmits them at VHF frequencies
- D. A transducer
24. Cause a herringbone pattern in facsimile
- A. Single-frequency interference
- B. Crosstalk
- C. Phase jitter
- D. Noise
25. The _______ in an FM receiver causes a stronger signal to dominate over a weaker signal on the same frequency.
- A. Capture effect
- B. Flywheel effect
- C. Hall effect
- D. Skin effect
26. A device that converts a 2-wire circuit to a 4-wire circuit.
- A. RS-232 interface
- B. Hybrid circuit
- C. Balun
- D. Stub
27. ______ theory is deciding between a set of hypothesis when given a collection of imperfect measurements.
- A. Estimation
- B. Traffic
- C. Decision
- D. Nyquist
28. ______ of a data reduction says that when reducing a set of data into the form of an underlying mode, one should be maximally non-committal with respect to missing data.
- A. Jaynes maximum entropy principle
- B. Kullback principle of minimum discrimination
- C. Minimum discrimination
- D. Maximum entropy
29. _______ is selecting the best value of a parameter from a continuum of possible values when gives a collection if imperfect measurements
- A. Estimation
- B. Traffic
- C. Decision
- D. Nyquist
30. Combination of madulator, channel, and detector.
- A. Transceiver
- B. Transponder
- C. T/R channel
- D. Discrete channel
31. What is the frequency band of DECT?
- A. 1.88 – 1.90 GHz
- B. 1.68 – 1.70 GHz
- C. 1.48 – 1.50 GHz
- D. 1.28 – 1.30 GHz
32. How many simultaneous calls does each DECT system can support?
- A. 96
- B. 12
- C. 24
- D. 49
33. How many simultaneous calls does a DECT radio transceiver can assess at any given time?
- A. 120
- B. 240
- C. 480
- D. 960
34. The AGC voltage of a radio receiver is always _______.
- A. Present before adjustments can be made
- B. DC, but may have either polarity positive DC
- C. Positive DC
- D. Negative
35. What is a concentrator?
- A. A system that improves the signal-to-noise ratio by compressing the volume range of a signal.
- B. A device that varies the characteristics of a carrier signal in accordance with the waveform of a modulating signal which contains useful information
- C. A switching system that lets a large number of telephone or data processing subscribers use a lesser number of transmission lines or a narrow bandwidth
- D. Equipment in the central office.
36. If you find that an SAW filter output is 6 dB down from the input of a receiver during test, ______
- A. This is normal.
- B. The device if faulty
- C. The receiver is improperly terminated
- D. The filter is not resonating
37. A triple conversion superheterodyne receiver, diode mixer stages are
- A. Operated in the linear region
- B. Operated in the nonlinear region
- C. Operated as Class-A amplifiers
- D. Operated as Class-B amplifiers
38. What is a leased line?
- A. A piece of wire used in a local area network in one building
- B. A piece of wire connecting a telephone set to a PABX
- C. A temporary connection of one computer to a mainframe via a modern and a telephone line
- D. A permanent circuit for a private use within a communication network
39. If two FM signals of different strengths are received on the same frequency
- A. One steady heterodyne will appear in the AM output
- B. Both will appear in the AF output
- C. Only the stronger will appear in the AF output
- D. Neither signal will be intelligence unless the weaker signal is at least 10 times
40. Cellular mobile system was first operated in
- A. 1979
- B. 1981
- C. 1983
- D. 1985
41. TACS is a cellular system with ______ channels.
- A. 666
- B. 1000
- C. 832
- D. 200
42. Supervisory Audio Tone (SAT) has _______ frequency.
- A. 5960 Hz
- B. 6000 Hz
- C. 6040 Hz
- D. 1004 z
43. What is the number of channels of a cellular system with an allocated spectrum of 25 MHz and with a channel of 30 kHz bandwidth?
- A. 833
- B. 240
- C. 1000
- D. 666
44. GSM uses what digital modulation technique?
- A. QAM
- B. GFSK
- C. BPSK
- D. GMSK
45. What is the power output of Personal Communication System (PCS)?
- A. 10 mW
- B. 75 mW
- C. 150 mW
- D. 10 W
46. RG-B8 cable has a loss of about ______ dB at cellular frequencies up to 15 ft. length.
- A. 2
- B. 1
- C. 4
- D. 3
47. The signals designed to keep the receivers and transmitters aligned.
- A. Carrier frequencies
- B. Pilot carrier signals
- C. Synchronizing signals
- D. Reference signals
48. If the spacing of a two-wire open air transmission line is 12 inches and the conductor diameter is 0.25 inch, the characteristic impedance is
- A. 547 Ω
- B. 357 Ω
- C. 273 Ω
- D. 300 Ω
49. The impedance of the quarterwave transformer used to match a 600 Ω line to a 300 Ω load is
- A. 382 Ω
- B. 424 Ω
- C. 565 Ω
- D. 712 Ω
50. When a line and a load are match the reflection coefficient is
- A. Unity
- B. Zero
- C. Positive infinity
- D. Negative infinity
Complete List of MCQs in Communications Engineering per topic
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