This is 100 items set of Practice Examination 13 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 13
Choose the letter of the best answer in each questions.
1. (ECE Board Problem, November 2000)
A point in the satellite orbit known to be the closest location to the surface of the earth.
- a) Zenith
- b) Perigee
- c) Apogee
- d) Azimuth
2. (ECE Board Problem, November 2000)
Determine from the following the common use of DSB in broadcast and telecommunication.
- a) Satellite Communication
- b) FM/TV Stereo
- c) Two-Way Communication
- d) Telephone System
3. (ECE Board Problem, November 2000)
Determine the image frequency of a broadcast band receiver using a 455 kHz IF tuned to 630 kHz-DZMM.
- a) 1085 kHz
- b) 1530 kHz
- c) 1540 kHz
- d) 1715 kHz
4. (ECE Board Problem, November 2000)
A phenomenon which causes the speed of light rays propagation in the fiber material changes, as it passes through different medium in the fiber.
- a) Bending
- b) Refraction
- c) Diffraction
- d) Reflection
5. (ECE Board Problem, November 1999)
An electronic equipment used in the radio communication to measure standing wave ratio.
- a) Radio meter
- b) Reflectometer
- c) Oscilloscope
- d) Wave Meter
6. (ECE Board Problem, November 2000)
Referred as an effect of parasitic elements in an antenna system.
- a) Decrease its directivity
- b) Makes the antenna omni directional
- c) Makes the antenna isotropic
- d) Increase its directivity
7. (ECE Board Problem, November 2000)
Radio wave concentration in the direction of the signal emitted by a directional antenna.
- a) Side lobe radiation
- b) Major lobe radiation
- c) Back lobe radiation
- d) Transmitted signal
8. (ECE Board Problem, November 2002)
What is the main principle used by ITU in determining the distribution of the orbit/ spectrum resources?
- a) Depending on the geographical boundary of a nation
- b) Efficient use and equitable access.
- c) Depending on a national sovereignty declaration
- d) Equal distribution
9. (ECE Board Problem, April 2000)
What quarter-wave transformer will match a 600Ω transmission line to an antenna whose value is 70 Ω?
- a.) 205 Ω
- b.) 502 Ω
- c.) 600 Ω
- d.) 75 Ω
10. (ECE Board Problem, November 1999)
Let us consider a frequency range of 405.0125 MHz to 405.0875 MHz and a 25 kHz channeling plan, determine the center frequency of the second channel from the lower limit.
- a.) 405.050 MHz
- b.) 405.0125 MHz
- c.) 405.025 MHz
- d.) 405.011 MHz
11. (ECE Board Problem, April 2000)
What is the reason why 5/8-whip vertical antenna is of advantage than quarter wave vertical whip antenna?
- a.) Less interference
- b.) Can handle high power signal
- c.) More gain
- d.) Flexible
12. (ECE Board Problem, April 1999)
Why is it that almost all switching type integrated data communication circuits are called digital?
- a.) They are mostly on/off devices.
- b.) They process digital information
- c.) They are small type
- d.) They are integrated circuits.
13. (ECE Board Problem, November 2000)
Which of the following shall be complied by an international ship pursuant to the global maritime distress and safety system implemented last 1999?
- a.) A facsimile
- b.) A radio personnel
- c.) A Morse code
- d.) A radio telegraph operator
14. (ECE Board Problem, November 2000)
Bit rate of a telecommunications carrier T2.
- a.) 7.312 Mb/s
- b.) 7.318 Mb/s
- c.) 6.511 Mb/s
- d.) 6.312 Mb/s
15. (ECE Board Problem, November 2000)
In propagation of radio signals through an aerial at what angle does not magnetic field is positioned with reference to the direction of propagation.
- a.) 180
- b.) 90
- c.) 0
- d.) 45
16. (ECE Board Problem, April 1999)
What is the frequency separation between the visual carrier and the upper limits of its total channel bandwidth of a monochrome TV broadcast?
- a.) 4.5 MHz
- b.) 4.75 MHz
- c.) 3.0 MHz
- d.) 1.25 MHz
17. (ECE Board Problem, November 2000)
In radio communications, the term trap antenna is referred to in one of the following statements.
- a.) Antenna with wide beam width
- b.) Those antennas with high rejecting capability to interfering signals.
- c.) Those antenna with long coverage in terms of distance
- d.) Antenna which can be used on more than one band due to the use of parallel LC networks.
18. (ECE Board Problem, April 1999)
What is the range of an AM broadcast frequency tolerance above or below its assigned frequency?
- a.) 25kHz
- b.) 20 Hz
- c.) 60 kHz
- d.) 120 kHz
19. (ECE Board Problem, April 2000)
Which part of the housing system in ECE code is a circular opening through the floor structure to allow the passage of cable and wire.
- a.) Insert
- b.) Sleeve
- c.) Raceway
- d.) Slot
20. (ECE Board Problem, April 2000)
What is the length of a simple quarter wave antenna using a VHF frequency of 150.55 MHz?
- a.) 0.98 ft.
- b.) 1.24 ft.
- c.) 1.80 ft.
- d.) 1.55 ft.
21. (ECE Board Problem, November 2000)
In the study of acoustics, the velocity of sound is dependent to one of the following.
- a.) Temperature
- b.) Loudness
- c.) Source of sound
- d.) Properties of the medium
22. (ECE Board Problem, April 1999)
Which of the following is not considered as one of the causes for the loss of signal power as light travels through a fiber optic?
- a.) Scattering
- b.) Intermodulation
- c.) Fiber bending
- d.) Absorption
23. (ECE Board Problem, November 1999)
Referred to as a light source of fiber optic, which supplies power level of 5 to 7 mW and having a narrow spectrum of emission.
- a.) Injection laser diode
- b.) Photodiode
- c.) Light emitting diode
- d.) Crystal diode
24. (ECE Board Problem, April 2000)
A digital mobile telephone system, which is called European derivative of Global System for Mobile Communication System operating at a higher frequency band.
- a.) E-TACS
- b.) IMTS
- c.) DCS-1800
- d.) TACS
25. (ECE Board Problem, April 1999)
Communication through the use of a modem is transmission of__________ data information in ____________ medium.
- a.) Analog, analog
- b.) Analog, digital
- c.) Digital, analog
- d.) Digital, digital
26. (ECE Board Problem, November 1999)
What type of emission is produced when amplitude modulated transmitter is modulated by a television signal?
- a.) A3F
- b.) F3C
- c.) F3F
- d.) A3C
27. (ECE Board Problem, April 1999)
A term, used in radio communication defining the frequency band from the lowest to its highest limits, designed to be passed through a component, system or a device with an acceptable attenuation.
- a.) Allocated band
- b.) Baseband
- c.) Bandwidth
- d.) Transmitted signal
28. (ECE Board Problem, April 2000)
Which body in the present ITU structure took the place of CCITT?
- a.) ITU-R
- b.) ITU-D
- c.) ITU-T
- d.) RAG
29. (ECE Board Problem, November 2002)
What is the frequency range of VLF?
- a.) 10-10 kHz
- b.) 30-300 kHz
- c.) 300-3000 kHz
- d.) 3-30 kHz
30. (ECE Board Problem, April 1999)
What is a wave front?
- a.) A voltage pulse in a conductor
- b.) A current pulse in the conductor
- c.) A voltage pulse across a resistor
- d.) A fixed point in an electromagnetic wave
31. (ECE Board Problem, November 2000)
How would you best describe an example of a pilot tone system use in commercial frequency modulation broadcast radio stations?
- a.) Frequency simplex
- b.) Time division
- c.) Stereo multiplex
- d.) QSK
32. (ECE Board Problem, April 1999)
Kind of broadcasting system where television programs are transmitted directly to home/user receivers via satellite, thus making the reception cover not only individuals in their homes but other places as well.
- a.) Pay TV
- b.) Direct to Home TV
- c.) Cable TV
- d.) VHF TV
33. (ECE Board Problem, November 1999)
In telecommunication, what do we call the difference in the voltage level between a driver and a terminator?
- a.) System gain
- b.) Noise margin
- c.) System loss
- d.) Noise difference
34. (ECE Board Problem, April 2000)
Why is parallel transfer method in data transmission faster then serial?
- a.) Wider channel bandwidth
- b.) Bits are transferred simultaneously
- c.) Bits are lighter in parallel
- d.) Due to faster changes in symbol
35. (ECE Board Problem, November 2000)
Radio frequency where waveguide is not used extensively.
- a.) 3,750 MHz
- b.) 2,000 MHz
- c.) 10,300 MHz
- d.) 150 MHz
36. (ECE Board Problem, April 1999)
One of the following central office switching equipment resistance limit refers to the longest subscriber loop length.
- a.) 1500 Ω
- b.) 300 Ω
- c.) 2000 Ω
- d.) 800 Ω
37. (ECE Board Problem, November 1999)
A particular area on the surface of the earth where the boresight of a steerable satellite beam is intended to be pointed.
- a.) Footprint area
- b.) Contour boresight area
- c.) Equivalent service area
- d.) Effective boresight area
38. (ECE Board Problem, April 1999)
Kind of information transfer in digital communication where the bits comprising one character are sent in sequence one at a time.
- a.) Parallel transmission
- b.) Batch transmission
- c.) Simplex transmission
- d.) Serial transmission
39. (ECE Board Problem, November 1999)
Which of the following antenna where its beamwidth is determine by the dimension of its horn, lens or reflector?
- a.) Whip antenna
- b.) Aperiodic antenna
- c.) Aperture antenna
- d.) Long wire antenna
40. (ECE Board Problem, April 1999)
In a transoceanic satellite conversation, how much is the typical delay before a reply is heard?
- a.) 200 ms.
- b.) 900 ms.
- c.) 50 ms.
- d.) 600 ms.
41. (ECE Board Problem, November 2000)
Position of the maritime ship main antenna, when the radio watch is secured or when the ship is in electrical storm.
- a.) AA
- b.) Main Transmitter
- c.) Grounded
- d.) HF
42. (ECE Board Problem, April 1999)
Best applies to an optical fiber core.
- a.) The same refractive index with the cladding
- b.) A higher refractive index than the cladding
- c.) A lower refractive index than the cladding
- d.) A lower refractive index than air
43. (ECE Board Problem, November 1999)
What measure will help you adopt on the antenna system of VHF or UHF mobile transceivers that has very low height antenna?
- a.) Increase transmitter to antenna cable
- b.) Use directional antenna
- c.) Check grounding system
- d.) Provide loading coil
44. (ECE Board Problem, April 1999)
How do you account the effect of light intensity on the refractive index of a fiber optic?
- a.) Decrease
- b.) Stable
- c.) Increase
- d.) Decrease by half
45. (ECE Board Problem, November 1999)
Refers to major advantage in the selection of a guided tube.
- a.) Durability
- b.) Low cost
- c.) Accuracy
- d.) High power
46. (ECE Board Problem, November 2000)
This is the terminal where riser cable pairs are terminated to serve a portion or an entire floor of a building.
- a.) Floor terminal distribution area
- b.) Raceway terminal
- c.) Floor distribution terminal
- d.) Riser terminal
47. (ECE Board Problem, November 1999)
This referred to a condition in a telephone network where the calling party cannot get connected to the party being called.
- a.) Disconnection
- b.) Open network
- c.) Blocked call
- d.) Loss call
48. (ECE Board Problem, April 2000)
In data transmission technology, signals such as voice or video are binary transmitted over a cable known as_________.
- a.) Video signals
- b.) Cable signals
- c.) Baseband signals
- d.) Audio signals
49. (ECE Board Problem, November 1999)
In satellite communications where satellite revolves in an orbit that forms a plane passing through the center of gravity of the earth, this center is called___________.
- a.) Geocenter
- b.) Earth center
- c.) Plane center
- d.) Center of gravity
50. (ECE Board Problem, November 1999)
In television, the color with the most luminance is ________________.
- a.) Blue
- b.) Green
- c.) Yellow
- d.) Red
51. (ECE Board Problem, April 2000)
What do you call the dissipated power affecting the antenna efficiency caused by arching effect in high-powered transmitters?
- a.) Dissipated power
- b.) Antenna resistance
- c.) Corona discharge
- d.) Antenna loss
52. (ECE Board Problem, November 1999)
What is the process in radio communication where information or intelligence signal at a lower frequency is put unto higher radio frequency for transmission to receiving station?
- a.) Detection
- b.) Mixing
- c.) Modulation
- d.) Demodulation
53. (ECE Board Problem, April 2000)
An inductor that is inserted in an antenna element or transmission line for the purpose of producing a resonant system at specific.
- a.) Reflector
- b.) Traps
- c.) Loading coil
- d.) Base loading
54. (ECE Board Problem, November 2000)
Satellite orbit around the earth are either, a) all are circular, b) all are elliptical, c) they are either circular or elliptical and d) none of these three.
- a.) D
- b.) B
- c.) C
- d.) A
55. (ECE Board Problem, April 2002)
What is the main reason why television picture signal uses amplitude modulation, while voice is frequency modulated?
- a.) Maintain the power signal at received end.
- b.) Eliminate attenuation of both video and audio
- c.) Maintain synchronized scanning between transmit and received video.
- d.) To minimize interference between signals at received end
56. (ECE Board Problem, April 2002)
Which of the following is referred to as a disadvantage of using squelch circuit?
- a.) Effect of AGC is reduced for strong signals.
- b.) Receiver sensitivity is reduced for strong signals.
- c.) Very weak signals might not be received.
- d.) Receiver selectivity is reduced for strong signals.
57. (ECE Board Problem, November 2000)
How does spatial isolation technique in satellite communications avoid interference?
- a.) Use of different polarity antennas.
- b.) Use of different types of antenna.
- c.) Employment of highly directional spot-beam
- d.) Use of low gain antenna
58. (ECE Board Problem, November 2000)
A parameter of light beam that do not change quantity when it enters one medium from another.
- a.) Intensity
- b.) Penetration
- c.) Frequency
- d.) Wavelength
59. (ECE Board Problem, November 2000)
How far is the visual carrier from the aural in the monochrome television broadcast channel have?
- a.) 1.5 MHz
- b.) 3 MHz
- c.) 4.5 MHz
- d.) 1.25 MHz
60. (ECE Board Problem, November 2000)
An order signed by former President F. Ramos last March 1998 providing the national policy in the operation and use of international satellite communication in the Philippines
- a.) Executive Order 3846
- b.) Executive Order 59
- c.) Executive Order 456
- d.) Executive Order 467
61. (ECE Board Problem, November 2000)
Where does the Secretary General in the organizational structure of present ITU report?
- a.) WTSG
- b.) TDAB
- c.) WRC
- d.) Council
62. (ECE Board Problem, November 2000)
In wire communication system using fiber optic, the packing fraction is related to one of the following statement when referred to fiber optic bundle.
- a.) Ratio of the total fiber radius, to the sum of the fiber optic bundle radius.
- b.) Ratio of half of the total fiber radius, to the sum of the fiber optic bundle radius.
- c.) Ratio of half-sectional area of the fiber optic bundle, to the cross-sectional area of the core
- d.) Ratio of the total cross-sectional area to the total cross-sectional area of the fiber bundle
63. (ECE Board Problem, April 2000)
Determine the local oscillator frequency of a broadcast band receiver using a 455 kHz IF and is tuned at 630 kHz.
- a.) 175 kHz
- b.) 1085 kHz
- c.) 280 kHz
- d.) 1530 kHz
64. (ECE Board Problem, April 1999)
One of the following is not a probable cause of radiating spurious signal from basic transmitter.
- a.) Harmonics
- b.) Regulated supply
- c.) Internal heating
- d.) Parasitic
65. (ECE Board Problem, April 2000)
What is the purpose of the two Yagi beam antenna on a VHF TV receiver?
- a.) Used to receiver VHF and UHF stations.
- b.) For receiving low and high band stations.
- c.) To increase selectivity
- d.) To increase sensitivity on both hands.
66. (ECE Board Problem, November 2000)
What is the noise that is develop in the RF amplifier front end of a TV receiver, which is indicated by a white dot in the picture?
- a.) Inter carrier
- b.) Black
- c.) Snow
- d.) IF
67. (ECE Board Problem, April 1999)
Region in the atmosphere where ducting occurs?
- a.) Ground region
- b.) Stratosphere
- c.) Ionosphere
- d.) Troposphere
68. (ECE Board Problem, April 2000)
Who issues an authority to install, operate, and maintain a cable television or render a television service within a specified area in the country?
- a.) Department of Transportation and Communication.
- b.) Board of Communication
- c.) Congress of the Philippines
- d.) National Telecommunications Communication
69. (ECE Board Problem, April 1999)
What is the source of sidebands in frequency modulation?
- a.) Oscillator
- b.) Baseband Frequency
- c.) Mixer
- d.) Carrier Harmonics
70. (ECE Board Problem, November 2000)
Which of the very thin layers of the tube’s front surface of the vidicon TV camera located at the middle layer and possess very high resistance when dark, while it reduces greatly when struck by photons of light?
- a.) Transparent Conductive Film
- b.) Photoresistive Layer
- c.) Photo Inductive Lens
- d.) Photosensitive Layer
71. (ECE Board Problem, April 2000)
One of the following refers to the standard frequency band limits of AM broadcast band?
- a.) 30-300 MHz
- b.) 88-108 MHz
- c.) 3-30 MHz
- d.) 535-1605 kHz
72. (ECE Board Problem, November 2000)
In a cable facilities for a building communications service,________ is referred to as the physical cable within a building or series of buildings which may include both main cable pairs and house cable pairs but not station wiring cable?
- a.) Entrance cable
- b.) Floor distribution cable
- c.) House cable
- d.) Building cable
73. (ECE Board Problem, April 1999)
What is the range of the lower sideband of an amplitude modulated signal whose carrier is 1.5 MHz and the intelligence component is 50 Hz to 20 kHz?
- a.) 1.550 MHz to 1.700 MHz
- b.) 1,499.980 kHz to 2,520.00 kHz
- c.) 1.48 MHz to 1.4995 MHz
- d.) 1,500.980 kHz to 2,480.00 kHz
74. (ECE Board Problem, November 2000)
A stage in cellular communications where voice channel is assigned to link up a call connection after a mobile or network originated a call.
- a.) Call termination
- b.) Call completion
- c.) Call connection
- d.) Call drops
75. (ECE Board Problem, April 1999)
How many satellites does not the GPS system consists?
- a.) 12 satellites
- b.) 3 satellites
- c.) 24 satellites
- d.) 60 satellites
76. (ECE Board Problem, April 2000)
Ratio of radiation resistance to the total resistance on an antenna?
- a.) Antenna gain
- b.) Antenna sensitivity
- c.) Antenna efficiency
- d.) Antenna ratio
77. (ECE Board Problem, November 2000)
What is the frequency of an LED at 1.9eV?
- a.) 645 GHz
- b.) 459 GHz
- c.) 458 THz
- d.) 337 THz
78. (ECE Board Problem, April 1999)
One of the characteristics of a fiber optic used in order to carry light in several modes of propagation or to become a multimode fiber.
- a.) Diameter of the core must be equal to the wavelength of the light to be carried.
- b.) Diameter of the core must be very much greater than the wavelength of the light to be carried.
- c.) Diameter of the core must be very small compared to the wavelength of light to be carried.
- d.) Diameter of the core must be much half the wavelength of the light to be carried.
79. (ECE Board Problem, April 2000)
One of the following is a communications filter generally used in the transceiver of a single sideband generator.
- a.) Low-pass filter
- b.) Crystal filter
- c.) Bandpass filter
- d.) Mechanical filter
80. (ECE Board Problem, April 2000)
In computer communications, the term RS-232C is referred to as__________.
- a.) Analog connection standard
- b.) Serial interference standard
- c.) Digital connection standard
- d.) Parallel port standard
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