This is 100 items set of Practice Examination 12 in Communications Engineering (Electronics Systems and Technology) composed of previous Board Exams Questions. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Communications Engineering within 5 hours. You have to get at least 70% to pass the subject. Communications Engineering is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Engineering (30%). Familiarize each and every questions to increase the chance of passing the ECE Board Examination.
Start the Test Yourself Exam 12
Choose the letter of the best answer in each questions.
1. (ECE Board Problem, November 2000)
Which of the following best described the primary source of errors in the transmission of data over telephone networks?
- a.) Thermal Noise
- b.) Crosstalk
- c.) Impulse Noise
- d.) Intermodulation
2. (ECE Board Problem, April 1999)
Which part of the HF marine antenna handles the broken safety link, in case it results collision, grounding or storm?
- a.) The lead-in.
- b.) The foremast.
- c.) The strong part.
- d.) The halyard.
3. (ECE Board Problem, April 2000)
A reduction in receiver sensitivity caused by unwanted high-level adjacent channel signals.
- a.) Intermodulation
- b.) Overloading
- c.) Interference
- d.) Desensitizing
4. (ECE Board Problem, November 2000)
Which of the following system uses frequency band 870-890 MHz as a transmit band of its base station?
- a.) Total Access Communication System (TACS)
- b.) Nordic Mobile Telephone (NMT)
- c.) Public Mobile System (PMS)
- d.) Advance Mobile Phone Services (AMPS)
5. (ECE Board Problem, November 2000)
Refers to a mobile earth station in the mobile-satellite service located on board ship.
- a.) Mobile Station
- b.) Ship Station
- c.) Ship Earth Station
- d.) Mobile Satellite Station
6. (ECE Board Problem, November 2002)
What is the electric field strength in millivolts per meter if the transmitted power is 30kW, at a distance of 5km?
- a.) 120 mV/m
- b.) 190 mV/m
- c.) 150 mV/m
- d.) 30 mV/m
7. (ECE Board Problem, November 2000)
Frequency band where Total Access Communication System is allocated.
- a.) 86-869 MHz; 821-824 MHz
- b.) 870-890 MHz; 825-845 MHz
- c.) 851-866 MHz; 806-821 MHz
- d.) 935-960 MHz; 890-915 MHz
8. (ECE Board Problem, November 2000)
Which of the following is used as a standard channel spacing for AM broadcast in the Philippines?
- a.) 25 kHz
- b.) 12.5 kHz
- c.) 40 kHz
- d.) 9 kHz
9. (ECE Board Problem, November 2000)
What is the frequency separation between the aural carrier and the lower limits of the total channel band of a monochrome TV broadcast?
- a.) 1.25 MHz
- b.) 4.5 MHz
- c.) 3.0 MHz
- d.) 5.75 MHz
10. (ECE Board Problem, November 2000)
Which satellite transponder has the most number of mixers?
- a.) Regenerative
- b.) Broadband
- c.) Double-Conversion
- d.) Channelized
11. (ECE Board Problem, November 2000)
An advantage of fiber optic co-axial cable as a result of coupling signals from one to the other due to changing magnetic field in one or both.
- a.) Feedback
- b.) Crosstalk
- c.) Electric Hazard
- d.) Shielding
12. (ECE Board Problem, April 2001)
How can even-order harmonics be reduced or prevented in transmitter amplifier design?
- a.) By using a push-push amplifier
- b.) By using push-pull amplifier
- c.) By operating Class C
- d.) By operating Class AB
13. (ECE Board Problem, April 2002)
With which emission type is the capture effect most pronounced?
- a.) FM
- b.) SSB
- c.) AM
- d.) CW
14. (ECE Board Problem, April 2002)
What is the term used to refer to the reception blockage of one FM-phone signal by another FM-phone signal?
- a.) Desensitization
- b.) Cross-modulation Interference
- c.) Capture Effect
- d.) Frequency Discrimination
15. (ECE Board Problem, April 2002)
What is the primary purpose of an RF amplifier in a receiver?
- a.) To provide most of the receiver gain.
- b.) To develop the AGC voltage.
- c.) To improve the receiver’s noise figure.
- d.) To vary\ the receiver image rejection by utilizing the AGC.
16. (ECE Board Problem, April 2002)
What is the product of the power fed to the antenna and its power gain?
- a.) Antenna Power
- b.) ERP
- c.) PEP
- d.) Peak Power
17. (ECE Board Problem, April 1999)
What is the reason why Hertz antenna is not normally used to radio station or receiver or transmitter antenna that has frequency below 2MHz?
- a.) The antenna receives more inter-modulation signal.
- b.) The antenna receive side becomes non-receptive.
- c.) The antenna will be physically very small.
- d.) The antenna will be physically very large.
18. (ECE Board Problem, November 1999)
In the study of transmission cable, twin lead is also referred to as________.
- a.) Twisted pair
- b.) Double cable
- c.) Ribbon cable
- d.) Open pair
19. (ECE Board Problem, November 1999)
In an open architecture concept of data communication, one of the following is not a function of a control layer.
- a.) Fault correction
- b.) Congestion control
- c.) Fault detection
- d.) Integrity of data
20. (ECE Board Problem, November 1999)
What are the two legislative function of the International Telecommunications Union in its international conference issues on orbital resources?
- a.) Assign frequencies and organizes conferences.
- b.) Allocates frequency bands for the services and determine the principle of distribution of orbit/spectrum resources.
- c.) Determine the principles of spectrum distribution and assignment of frequencies.
- d.) Conduct conferences and allocation of orbital slot.
21. (ECE Board Problem, April 2002)
What transmission medium is capable of carrying up to 10Gbps capacity?
- a.) Twisted pair
- b.) Optical fiber
- c.) Coax
- d.) Microwave link
22. (ECE Board Problem, April 2002)
What is the controlling node of a star topology system?
- a.) Modem
- b.) Codec
- c.) Hub
- d.) ADC
23. (ECE Board Problem, April 2002)
What is the most efficient topology used by small business organization?
- a.) Mesh
- b.) Star
- c.) Bus
- d.) Ring
24. (ECE Board Problem, April 2002)
Which of the following network topology has the fastest speed?
- a.) Star
- b.) Ring
- c.) Bus
- d.) Mesh
25. (ECE Board Problem, April 2002)
The latest and most advanced equipment in data communications is a/an___________.
- a.) Amplifier
- b.) Simulator
- c.) Protocol analyzer
- d.) Spectrum analyzer
26. (ECE Board Problem, April 2002)
Which has the highest priority in radio telephone communication?
- a.) Distress
- b.) Safety
- c.) Urgency
- d.) Roger
27. (ECE Board Problem, April 2002)
In satellite communications, what is the frequency of the V-band?
- a.) 27-40 GHz
- b.) 4-8 GHz
- c.) 8-12GHz
- d.) 40-75 GHz
28. (ECE Board Problem, April 2002)
What is meant by the term antenna gain?
- a.) The numerical ratio relating the radiated signal strength of an antenna to that of another antenna.
- b.) The ratio of the signal in the forward direction to the signal in the back direction.
- c.) The ratio of the amount of power to produce by the antenna compared to the output power of the transmitter.
- d.) The final amplifier gain minus the transmission line losses.
29. (ECE Board Problem, April 2002)
What is an advantage using a trap antenna?
- a.) It has antenna gain
- b.) It minimizes harmonic radiation
- c.) It has high directivity in the high frequency bands
- d.) It may be used for multiband operations
30. (ECE Board Problem, April 2002)
What is the wavelength of a shorted stub used to absorb even harmonics?
- a.) 0.5 wavelength
- b.) 1/3 wavelength
- c.) 0.25 wavelength
- d.) 1/8 wavelength
31. (ECE Board Problem, November 2002)
Who coined the term fiber optics?
- a.) Hansell
- b.) Hopkins
- c.) N.S. Kapany
- d.) Van heel
32. (ECE Board Problem, April 2002)
How does the length of the reflector element of a parasitic beam antenna compare with that of a driven element?
- a.) It is about 5% longer.
- b.) It is about 5% shorter
- c.) It is twice as long
- d.) It is one-half as long
33. (ECE Board Problem, April 2001)
In a half wave antenna, where are the current nodes?
- a.) At the ends
- b.) At the center
- c.) One-half of the way from the feed point toward the end.
- d.) Three-quarters of the way from the feed point toward the end.
34. (ECE Board Problem, April 2002)
Why is a loading coil often used with an HF mobile antenna?
- a.) To improve reception
- b.) To lower the losses
- c.) To lower the Q.
- d.) To tune out the capacitive resistance.
35. (ECE Board Problem, April 2002)
What is a frequency discriminator?
- a.) A circuit for detecting FM signals
- b.) A circuit for filtering two closely adjacent signals.
- c.) An automatic band switching circuit.
- d.) An FM generator.
36. (ECE Board Problem, April 2002)
What is the period of a wave?
- a.) The time required to complete one cycle.
- b.) The number of degrees in one cycle.
- c.) The number of zero crossing in one cycle.
- d.) The amplitude of the wave.
37. (ECE Board Problem, April 2002)
The implementing guidelines on international satellite communications is___________.
- a.) EO 467
- b.) EO 846
- c.) DO 11
- d.) DO 88
38. (ECE Board Problem, April 2002)
What was implemented in 1999 which has the purpose of aiding the maritime navigation using satellite as well as advanced terrestrial communication system?
- a.) GMDSS
- b.) AMPS
- c.) GLONASS
- d.) NAVSTAR
39. (ECE Board Problem, April 2002)
Which of the following is not a DTE?
- a.) Telephone set
- b.) Computer
- c.) Bridge
- d.) Printer
40. (ECE Board Problem, April 2002)
What is the transmission of data through a different time slots?
- a.) TDM
- b.) FDM
- c.) WDM
- d.) CDM
41. (ECE Board Problem, April 2002)
What is the parameter that affects the computation of image frequency?
- a.) Q
- b.) fLO
- c.) fIF
- d.) D
42. (ECE Board Problem, April 2002)
Which of the following could not be observed in a microwave communications?
- a.) LOS
- b.) Wide BW
- c.) Better Signal Penetration
- d.) Directional Antenna
43. (ECE Board Problem, April 2002)
The service area where the signal is subject to fading with no objectionable interference.
- a.) Primary service area
- b.) Secondary service area
- c.) Intermittent service area
- d.) Quarternary service area
44. (ECE Board Problem, April 2002)
By examining the following antenna type, determine which is properly terminated?
- a.) Non-resonant Type
- b.) Half-wave Dipole
- c.) Whip antenna Type
- d.) Resonant Type
45. (ECE Board Problem, April 2001)
What is the third letter symbol in the emission designation for telemetry?
- a.) F
- b.) B
- c.) D
- d.) N
46. (ECE Board Problem, April 2002)
What is the frequency tolerance of FM broadcasting?
- a.) 25 kHz
- b.) 20 kHz
- c.) 2 kHz
- d.) 30 kHz
47. (ECE Board Problem, April 2001)
Which of the following is commonly used search engine?
- a.) .edu
- b.) www
- c.) .org
- d.) Excite
48. (ECE Board Problem, April 2001)
When the electric field is perpendicular to the surface of the earth, what is the polarization of the electromagnetic wave?
- a.) Vertical
- b.) Horizontal
- c.) Circular
- d.) Elliptical
49. (ECE Board Problem, April 2001)
What is the deviation ratio of an FM signal if the maximum allowable deviation is 12 kHz and the maximum intelligence frequency is 4 kHz?
- a.) 3
- b.) 48
- c.) 2/3
- d.) 1/3
50. (ECE Board Problem, April 2002)
What is the typical satellite communications bandwidth?
- a.) 20 MHz
- b.) 30 MHz
- c.) 40 MHz
- d.) 500 MHz
51. (ECE Board Problem, April 2001)
The following are not used in radio communications, except________.
- a.) Infrared
- b.) Cosmic
- c.) X-ray
- d.) Gamma
52. (ECE Board Problem, April 2001)
A modem which can be used to send data and fax.
- a.) Bell 212A
- b.) ARQ
- c.) Fax modem
- d.) Data modem
53. (ECE Board Problem, April 2001)
What is the output of a balanced modulator.
- a.) SSB
- b.) DSB
- c.) ISB
- d.) VSB
54. (ECE Board Problem, April 2002)
An emission technique where the total current will be twice as much when the modulation index is doubled.
- a.) J3E
- b.) H3E
- c.) A3E
- d.) R3E
55. (ECE Board Problem, April 2001)
Which of the following uses frequency modulator circuit?
- a.) A3E
- b.) F3E
- c.) H3E
- d.) R3E
56. (ECE Board Problem, April 2002)
What is used to display harmonics and fundamental frequency?
- a.) Oscilloscope
- b.) Spectrum Analyzer
- c.) Wattmeter
- d.) Ohmmeter
57. (ECE Board Problem, November 2002)
What is the free space loss, in dB, of a microwave system when the frequency is 6 GHz at 40km apart?
- a.) 170 dB
- b.) 150 dB
- c.) 160 dB
- d.) 140 dB
58. (ECE Board Problem, April 2001)
When the signal becomes weak, the base will request the MTSO to find another site.
- a.) Roaming
- b.) Hand-off
- c.) Frequency Re-use
- d.) Cell splitting
59. (ECE Board Problem, April 2001)
What is the interference between the switching office and the mobile unit.
- a.) Cell sites
- b.) MTSO
- c.) Microwave link
- d.) Base station
60. (ECE Board Problem, April 2001)
Which is not an omni-directional antenna?
- a.) Vertical folded dipole
- b.) Discone
- c.) Rhombic
- d.) Marconi
61. (ECE Board Problem, April 2001)
Which satellite band is affected by VHF signals?
- a.) L
- b.) C
- c.) P
- d.) Ku
62. (ECE Board Problem, April 2001)
What is produced by over-modulation in AM?
- a.) Sidebands
- b.) Jitter
- c.) Glitch
- d.) Spurious Signal
63. (ECE Board Problem, April 2001)
_____ is the process of sending out the information in all directions.
- a.) Navigation
- b.) Broadcasting
- c.) Acoustics
- d.) Telemetry
64. (ECE Board Problem, April 2001)
How do you increase the electrical length of an antenna?
- a.) Add an inductor in parallel
- b.) Add an inductor in series
- c.) Add a capacitor in series
- d.) Add a resistor in series.
65. (ECE Board Problem, April 2001)
What is the usual electrical length of a driven element in HF beam antenna?
- a.) ¼ wavelength
- b.) ½ wavelength
- c.) ¾ wavelength
- d.) 1 wavelength
66. (ECE Board Problem, April 2002)
What is the point in the satellite as it crosses the equator?
- a.) Apogee
- b.) Node
- c.) Perigee
- d.) Orbit
67. (ECE Board Problem, November 2001)
Direct Distance Dialing is________.
- a.) Private line
- b.) Public line
- c.) Lease line
- d.) Dial-up
68. (ECE Board Problem, November 2001)
A path wherein a satellite crosses in the equator heading south.
- a.) Ascending node
- b.) Descending node
- c.) Orbital
- d.) Polar
69. (ECE Board Problem, November 2001)
In what frequency band does 4-6 GHz fall in the satellite communications?
- a.) C-Band
- b.) L-Band
- c.) X-band
- d.) K-band
70. (ECE Board Problem, November 2001)
A computer network found in the same building.
- a.) Local area network
- b.) Wide area network
- c.) Metropolitan area network
- d.) PLL
71. (ECE Board Problem, April 2002)
Which of the following antenna feedline can easily be buried underground for a distance without adverse effects?
- a.) Waveguide
- b.) Twisted pair
- c.) Coaxial cable
- d.) Twin lead
72. (ECE Board Problem, April 1999)
In the study of wave propagation, a condition at which zero absorption of radio waves is describe as__________.
- a.) Zero reflection medium
- b.) Neutral medium
- c.) Free space medium
- d.) Non-active medium
73. (ECE Board Problem, November 1999)
Which of the following in the radio emission designation refers to the first symbol?
- a.) Nature of signal modulating the main carrier
- b.) Type of modulation of the main carrier
- c.) Emission bandwidth
- d.) Type of information
74. (ECE Board Problem, November 2000)
The process of exchanging predetermine codes and signals in telecommunications between two data terminals to establish a connection is called.
- a.) Hands-off
- b.) Polling
- c.) Handshake
- d.) Demodulation
75. (ECE Board Problem, April 2000)
It is an electronic instrument which can be referred to as a miniature radio transmitter and can be made to generate signals at any desired frequency, normally it is used for test purposes.
- a.) Volt-ohm milliammeter
- b.) Signal generator
- c.) Oscilloscope
- d.) Wavemeter
76. (ECE Board Problem, April 1999)
A network interconnection facility which is used to interconnect networks whose architectures are entirely different is called________.
- a.) Bridge
- b.) Router
- c.) Gateway
- d.) Repeater
77. (ECE Board Problem, November 1999)
Type of multi-channel transmission in the optic fiber communication that uses a twisted pair coupler to transmit two signals of different wavelengths.
- a.) Frequency-division multiplexing
- b.) Forward-division multiplexing
- c.) Pulse-code multiplexing
- d.) Time-division multiplexing
78. (ECE Board Problem, April 2000)
These are the rules in data communications intended for establishing data links and message interpretation.
- a.) Mode
- b.) EIA Rules
- c.) CCIR Rules
- d.) Protocol
79. (ECE Board Problem, November 1999)
A radio station in mobile service intended to be used while in motion or during halts at unspecified points.
- a.) Maritime radio station
- b.) Land mobile station
- c.) Mobile station
- d.) Mobile earth station
80. (ECE Board Problem, April 1999)
What is the advantage on the TV receiver audio by employing FM audio and AM video on the television transmitter?
- a.) FM receiver rejects static noise
- b.) FM receiver is basically insensitive to amplitude modulation
- c.) FM receiver is basically insensitive to amplitude modulation
- d.) FM receiver is clear over AM.
81. (ECE Board Problem, April 1999)
What does the elastic store refereed to in the time division multiplex system used in fiber optic?
- a.) Amplifier
- b.) Holding memory
- c.) Reflector
- d.) Timer
82. (ECE Board Problem, November 1999)
What are the two general categories of methods for generating emission F3E?
- a.) The only way to produce an emission F3E signal is with a reactance modulator on the oscillator.
- b.) The only way to produce an emission F3E signal is with a balanced modulator on the oscillator.
- c.) The only way to produce an emission F3E signal is with a balanced modulator on the audio amplifier.
- d.) The only way to produce an emission F3E signal is with a reactance modulator on the final amplifier.
83. (ECE Board Problem, November 2002)
Pressure us measured in terms of Pascal, microbar, or__________.
- a.) Newtons
- b.) Newtons per meter
- c.) Newtons per meter squared
- d.) Pascal per meter squared
84. (ECE Board Problem, April 1999)
What is the function of the network layer in the computer communications?
- a.) Parity control
- b.) Direction control
- c.) Congestion control
- d.) Error control
85. (ECE Board Problem, April 2000)
Which of the following limits the top speed of transmitting information in fiber optic?
- a.) Noise
- b.) Detector speed
- c.) Time domain
- d.) Refractor index
86. (ECE Board Problem, April 1999)
A mobile telephone system which uses an analogue cellular radio standard which was superseded by Advanced Mobile Phone System in the U.S.
- a.) TDMA
- b.) IMTS
- c.) CDMA
- d.) D-AMPS
87. (ECE Board Problem, November 2000)
Satellite that rotates around the earth in a low altitude elliptical or circular pattern.
- a.) Geosynchronous Satellite
- b.) Prograde
- c.) Nonsynchronous satellite
- d.) Apogee
88. (ECE Board Problem, April 2000)
One of the following processes or system best describe an example of a pilot tone system normally use in commercial broadcast FM stations.
- a.) Time division
- b.) Frequency division
- c.) Stereo multiplex
- d.) QSK
89. (ECE Board Problem, November 2000)
What is the main reason why coaxial cable is not used in microwave signal transmission?
- a.) Wide bandwidth
- b.) Number of repeaters
- c.) Low impedance
- d.) High attenuation
90. (ECE Board Problem, April 2000)
Refers to a characteristic of a multimode fiber optic.
- a.) Cladding thickness is less than the radius of the core and diameter of the core must be greater than the wavelength of the light to be carried.
- b.) Cladding thickness is greater than the radius of the core and the diameter of the core must be lesser than the wavelength of the light to be carried.
- c.) Cladding thickness is less than the radius of the core and the diameter of the core must be lesser than the wavelength of the light to be carried.
- d.) Cladding thickness is greater than the radius of the core and the diameter of the core must be much greater than the wavelength of the light to be carried.
91. (ECE Board Problem, April 2000)
Two or more LAN linked together over the wide geographical area.
- a) HAN
- b) WAN
- c) MAN
- d) RAN
92. (ECE Board Problem, April 2000)
A process of sending data in computing technology by asking each remote computer terminal one at a time if such computer terminal has data to send.
- a) Selection
- b) Networking
- c) Polling
- d) Coding
93. (ECE Board Problem, November 1999)
What is the primary purpose of an RF amplifier in receiver?
- a) To vary the receiver image rejection by utilizing the AGC.
- b) To provide the most receiver gain.
- c) To develop the AGC voltage.
- d) To improve the receiver’s noise figure.
94. (ECE Board Problem, April 2000)
Why are fiber optic cables considered less expensive compared to coaxial cables in communication system?
- a) Coaxial is very expensive than fiber optic.
- b) Due to weight.
- c) Installation cost of coaxial.
- d) Use of less repeaters.
95. (ECE Board Problem, November 1999)
Refers to as a linkage by wire, radio, satellite or other means, of two or more telecommunications carrier or operators with one another for the purpose of allowing or enabling the subscriber of one carrier or operator to access or reach the subscribers of the other carrier or operator.
- a) Interconnection
- b) Toll patching
- c) Gateway
- d) Outside plant sharing
96. (ECE Board Problem, November 1999)
In order to have an effective radio antenna the design of its radiator must have a minimum length equivalent to________.
- a) Λ/10
- b) Λ/4
- c) Λ/14
- d) Λ/6
97. (ECE Board Problem, April 2000)
Referred as the forward link channel of the cellular duplex system.
- a) Cell to Cell
- b) Mobile to Mobile unit
- c) Mobile to Cell unit
- d) Cell to Mobile unit
98. (ECE Board Problem, November 2000)
Method of a telecommunications operation where transmission can be made simultaneously in both direction of a channel.
- a) Semi-duplex Operation
- b) Duplex Operation
- c) Half-duplex Operation
- d) Simplex Operation
99. (ECE Board Problem, April 2000)
Which symbol in radio signal emission designation is referred to type of modulation of the main carrier?
- a) Second
- b) Fourth
- c) Third
- d) First
100. (ECE Board Problem, November 2000)
What type of emission is produced when an amplitude-modulated transmitter is modulated by a facsimile signal?
- a. A3F
- b. F3
- c. A3C
- d. F3F
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