# Communications Engineering Exam 6: ECE Pre-Board

Pre-Board Examinations in Communications Engineering Module 6 composed of previous Board Exams Questions. Familiarize each and every questions.

This is 100 items set of Practice Examination 6 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 6

Choose the letter of the best answer in each questions.

1. ECE Board Exam April 1998

When adjusting an RF filter on a transmitter using a dummy load, how much watts dissipation should it stand to test a 150 watts transmitter?

• A. 75 watts
• B. 300 watts
• C. 50 watts
• D. 150 watts

2. ECE Board Exam April 1998

When does broadcast station conduct and equipment test?

• A. During day time
• B. During night time
• C. At any time
• D. During experimental period

3. ECE Board Exam April 1998

Channel 7 of the regular television channel belongs to which band?

• A. Low VHF band
• B. High VHF band
• C. Low UHF band
• D. High UHF band

4. ECE Board Exam April 1998

Which of the following is one of the possible causes for a slow drift of frequency in a self exited transmitter oscillator circuits resulting to a poor frequency stability?

• A. Poor soldered connections
• B. Power supply voltage changes
• C. Loose connections in the oscillator, amplifier, or antenna circuits
• D. DC and RF heating of resistors, causing then to change values.

5. ECE Board Exam April 1998

A third symbol radio emission which represent telephone transmission including sound broadcasting.

• A. W
• B. F
• C. C
• D. E

6. ECE Board Exam April 1998

Which of the following is not a common microwave application?

• B. Data transmission
• C. Space communications
• D. Mobile radio

7. ECE Board Exam April 1998

Which of the following is referred to as a radio emission without sidebands

• A. Analog
• B. Carrier
• C. Data
• D. Voice

8. ECE Board Exam April 1998

Ho w many times bigger does the bandwidth of a fiber optic multimode have over a cable?

• A. 50 times bigger
• B. 100 times bigger
• C. 10 times bigger
• D. 5 times bigger

9. ECE Board Exam April 1998

Type of antenna which is normally used for satellite tracking service.

• A. Omni
• B. Helical
• C. Yagi
• D. Dipole

10. ECE Board Exam April 1998

One of the following is referred to as a major component of an optical time domain reflectometer

• A. Pulse generator and vertical plate
• B. Laser and horizontal plate
• C. Pulse generator laser
• D. Vertical and horizontal plate

11. ECE Board Exam April 1998

One of the commonly used domain in the internet service.

• A. Yahoo
• B. http
• C. com
• D. www

12. ECE Board Exam April 1998

What is meant by the term radiation resistance for an antenna?

• A. The resistance in the trap coils to received signal
• B. An equivalent resistance that would dissipate the same amount of power as that radiated from an antenna
• C. The specific impedance of the antenna
• D. Losses in the antenna elements and feed line

13. ECE Board Exam April 1998

Referred to an oscillator signal “leak through” from a properly neutralized amplifier such as a master oscillator power amplifier.

• A. Carrier
• B. Stray signal
• C. Back wave
• D. Loss wave

14. ECE Board Exam April 1998

An advantage of optic fiber rejecting an induced noise signals from magnetic field or solar storms flux.

• A. Electric hazard
• B. Cross talk
• C. Immunity to noise
• D. Shielding

15. ECE Board Exam April 1998

What kind of effect is referred to a varying light producing a varying voltage output of a detector?

• A. Current effect
• B. Voltage effect
• C. Resistive effect
• D. Photovoltaic effect

16. ECE Board Exam April 1998

______ is known to be the first satellite capable of receiving and transmitting simultaneously.

• A. Syncom I
• B. Telstar I
• C. Score
• D. Aguila

17. ECE Board Exam April 1998

The extremely high frequency (EHF) band is in the radio spectrum range of _______.

• A. 30 to 300 kHz
• B. 30 to 300 GHz
• C. 3 to 30 MHz
• D. 3 to 30 GHz

18. ECE Board Exam April 1998

One of the following is not among the advantages of series modulation

• A. No transformer
• B. Suppressed white noise
• C. Simple
• D. Modulates any frequency

19. ECE Board Exam April 1998

What do you call the service area of a standard AM broadcast where fading is allowed but not objectionable co-channel interference?

• A. Experimental
• B. Secondary
• C. Tertiary
• D. Primary

20. ECE Board Exam April 1998

A third symbol emission which represent television.

• A. C
• B. D
• C. F
• D. A

21. ECE Board Exam April 1998

In telecommunications when we call data communications it means the transmission of________.

• A. Voice and video
• B. Voice
• C. Video
• D. Computer data

22. ECE Board Exam April 1998

If frequency range of 401.000MHz to 401.050MHz has to be channelized at 12.5 kHz between channel, what is the center of its first channel from the lower limit?

• A. 401.125 MHz
• B. 401.00625 MHz
• C. 401.025 MHz
• D. 401.0125 MHz

23. ECE Board Exam April 1998

Determine the effective radiated power of 20 kW TV broadcast transmitter whose antenna has a field gain of 2.

• A. 40 kW
• B. 80,000 watts
• C. 40,000 watts
• D. 8,000 watts

24. ECE Board Exam April 1998

In indication signal for a handshake form the DCE to the DTE in response to an active condition for the request to send a signal.

• A. Data transmission
• B. Clear to send
• C. Receive data
• D. Data set ready

25. ECE Board Exam April 1998

In amplitude modulation technique the unmodulated carrier is referred to as having ______.

• A. 100% modulation
• B. 0% modulation
• C. 50% modulated
• D. Over modulated

26. ECE Board Exam April 1998

One of the following is not among the major components required on board ship under the global maritime distress and safety system.

• A. On board radio facilities
• B. Radio operator telegraphy onboard
• C. Shore base facilities
• D. Radio personnel on board

27. ECE Board Exam April 1998

In what form does the information of data communications is transmitted between two points?

• A. Alphanumeric form
• B. Alphabetic form
• C. Numeric form
• D. Binary form

28. ECE Board Exam April 1998

Width of frequency band just enough to ensure the transmission of information at a required rate and quality required, and under a specified condition and class of emission.

• A. Occupied bandwidth
• B. Transmission bandwidth
• C. Necessary bandwidth
• D. Frequency bandwidth

29. ECE Board Exam April 1998

Refers to one of the front end circuit of a VHF TV superheterodyne receiver which is usually a separate circuit coupled to the mixer.

• A. Antenna feed
• B. AGC
• C. RF amplifier
• D. Local oscillator

30. ECE Board Exam April 1998

All bits in character are sent and received ______ in serial port.

• A. In groups of 3 bits
• B. One at a time
• C. In groups of 2 bits
• D. Simultaneously

31. ECE Board Exam April 1998

One of the following is a possible cause of an abrupt frequency variation in a self exited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency oscillation.

• A. Heating and expansion of oscillator coil
• B. DC and RF ac heating of resistors which cause change in values
• C. Heating of capacitor in the oscillator
• D. Loose connections in the oscillator, amplifier, or antenna circuits.

32. ECE Board Exam April 1998

Which of the following parts of the radio receiver represent the component that extracts the desire RF signal from the electromagnetic wave?

• A. AF amplifier
• B. Antenna
• C. Detector
• D. Crystal

33. ECE Board Exam April 1998

It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation, taken under the normal operating conditions.

• A. Carrier power
• B. Rated power
• C. Mean power
• D. Peak envelop power

34. ECE Board Exam April 1998

Determine from the following radio frequency that falls under the very high frequency band of the radio spectrum.

• A. 345.00 MHz
• B. 144.50 MHz
• C. 235.50 MHz
• D. 450.00 MHz

35. ECE Board Exam April 1998

What is the typical number of bits in a static memory location?

• A. 1
• B. 2
• C. 16
• D. 8

36. ECE Board Exam April 1998

What controls the contrast of a television cathode ray picture?

• A. AFC
• B. video stage gain
• C. Audio gain control
• D. CRT bias

37. ECE Board Exam April 1998

Determine the dB gain of a receiving antenna which delivers a microvolt signal to a transmission line over that of an antenna that delivers a 20 microvolt signal under identical circumstances.

• A. 10 dB
• B. 6 dB
• C. 3 dB
• D. 8 dB

38. ECE Board Exam April 1998

Refers to one of a commonly used internet service domain.

• A. www
• B. http
• C. gov
• D. infoseek

39. ECE Board Exam April 1998

A law that specifically requires the service of a duly registered electronics and communications engineer in the designing installation and construction, operation and maintenance of radio stations.

• A. Act 3846
• B. LOl 1000
• C. R.A. 5734
• D. Dept. order 88

40. ECE Board Exam April 1998

Which band does channel 14 of the television channel belong?

• A. High VHF band
• B. EHF band
• C. UHF band
• D. Low VHF band

41. ECE Board Exam April 1998

How many ship’s area is designated in the implementation of the global maritime distress and safety system.

• A. Four
• B. Six
• C. Three
• D. Two

42. ECE Board Exam April 1998

What kind of receiver is used in conventional telephone handset?

• A. Capacitor
• B. Electromagnetic
• C. Carbon
• D. Ceramic

43. ECE Board Exam April 1998

Determine the lower half-power frequency of a class-C amplifier having upper half-power frequency of 10.025 MHz, a resonant frequency 5 MHz and a circuit Q of 10.

• A. 1.0025 MHz
• B. 10.525 MHz
• C. 0.5 MHz
• D. 10 MHz

44. ECE Board Exam April 1998

This is referred to a product of simultaneous frequency and amplitude modulation or a carrier frequency variation which produces unwanted distortion.

• A. Absorption modulation
• B. Simultaneous modulation
• C. Dynamic instability
• D. Series modulation

45. ECE Board Exam April 1998

Main basic components of a data communication are composed of the following.

• A. Computer, modern and router
• B. Computer, bridge and gateway
• C. Transmitter, channel and receiver
• D. Transmitter, computer and modem

46. ECE Board Exam April 1998

The international radio consultative committee is referred to in international radio communication as ______.

• A. IRCC
• B. ITU
• C. IRR
• D. CCIR

47. ECE Board Exam April 1998

Refers to a continuous tone generated in a local exchange terminal through a combination of two frequencies 350 Hz, and 440 Hz.

• A. Busy tone
• B. Call waiting tone
• C. Dial tone
• D. Standard tone

48. ECE Board Exam April 1998

One of the advantages of fiber optic which is referred to the volume of capacity of signals it can carry.

• A. Security
• B. Weight
• C. Bandwidth
• D. Physical size

49. ECE Board Exam April 1998

Assume a frequency range of 401.000 MHz to 401.050 MHz, if you apply 25 kHz channeling plan, determine the center frequency of the first channel from the lower limit.

• A. 401.010 MHz
• B. 401.0125 MHz
• C. 401.025 MHz
• D. 401.00625 MHz

50. ECE Board Exam April 1998

The stability of transmitted signal from a simple Hartley oscillator single transmitter which is coupled to and antenna wire affected by ______.

• A. Chirping of oscillator
• B. Closer coupling between the oscillator and the antenna.
• C. Location of antenna
• D. Material of antenna

51. ECE Board Exam April 1998

Refers to the first symbol in an emission designation with an amplitude modulated main carrier represented by letter H.

• A. Single sideband suppressed carrier
• B. Double sideband full carrier
• C. Independent sideband
• D. Double sideband

52. ECE Board Exam April 1998

Assume a frequency range of 405.0125 MHz to 405.0875 MHz and 25 kHz channeling plan, determine the center frequency of the second channel from the lower limit.

• A. 405.030 MHz
• B. 405.025 MHz
• C. 405.050 MHz
• D. 405.075 MHz

53. ECE Board Exam April 1998

An entity, relying on the transmission, switching and local distribution facilities of local exchange and inter-exchange operators, and overseas carriers, offers enhanced services beyond those ordinarily provided by such carriers.

• A. International carrier
• B. Value-added service provided
• C. Inter-exchange carrier
• D. Local exchange carrier

54. ECE Board Exam April 1998

Which of the following refers to full duplex transmission?

• A. One at a time transmission
• B. Two transmission medium
• C. Intermittent transmission
• D. Two way simultaneous transmission

55. ECE Board Exam April 1998

What is the first symbol of a radio signal transmission having an amplitude modulated signal carrier, double side band?

• A. C
• B. B
• C. H
• D. A

56. ECE Board Exam April 1998

Best choice of transmission line component to couple a coaxial line to a parallel-wire line

• A. Shorting
• B. Balun
• C. Slotted line
• D. Directional coupler

57. ECE Board Exam April 1998

Which of the following refers to the video signal amplitude that determines the quality of the picture?

• A. Chrominance
• B. Luminance
• C. Brightness
• D. Contrast

58. ECE Board Exam April 1998

________ is the method of encoding audio signals used in US standard 1544 kbit/s 24 channel PCM systems.

• A. Shannon’s law
• B. A-law
• C. Newton’s law
• D. Mu-law

59. ECE Board Exam April 1998

In radio regulation, the first symbol in the designation of radio emission is ______.

• A. Bandwidth
• B. Nature of signal(s) modulation the main carrier
• C. Type of modulation of the main carrier
• D. Type of information to be transmitted

60. ECE Board Exam April 1998

Who is the principal administrator of republic act 7925?

• A. BOC
• B. DOTC
• C. Congress
• D. NTC

61. ECE Board Exam April 1998

What is the term for the ration of the radiation resistance of an antenna to the total resistance of the system?

• A. Effective radiated power
• B. Beamwidth
• C. Radiation conversion loss
• D. Antenna efficiency

62. ECE Board Exam April 1998

Where does the AM broadcast band located in the spectrum band?

• A. HF band
• B. VHF band
• C. LF band
• D. MF band

63. ECE Board Exam April 1998

What determines the velocity factor in transmission line?

• A. The center conductor resistivity
• B. Dielectrics in the line
• C. The termination impedance
• D. The line length

64. ECE Board Exam April 1998

Refers to an address that identifies a server on the network and a particular document on the server

• A. Hypertext
• B. HTML
• C. Wide area network
• D. Uniform resource locator

65. ECE Board Exam April 1998

Type of emission produced by one of the early radio transmitter in trains of damped RF ac waves where its oscillator is coupled to a long wire antenna, normally used in radio telegraph and having sidebands on its carrier.

• A. Digital emission
• B. Key emission
• C. Cycle emission
• D. Spark emission

66. ECE Board Exam April 1998

Is a kind of satellite which has a period of revolution equivalent to the period of rotation of the earth about its axis.

• A. Passive satellite
• B. Synchronous satellite
• C. Active satellite
• D. Geosynchronous satellite

67. ECE Board Exam April 1998

Electromagnetic waves of frequencies arbitrarily lower than 3,000 GHz, propagated in space without artificial guide.

• A. Space waves
• B. Terrestrial waves
• C. Mobile
• D. Hertzian waves

68. ECE Board Exam April 1998

Frequencies above ______ kHz, are referred to as the radio frequencies.

• A. 20
• B. 2
• C. 10
• D. 200

69. ECE Board Exam April 1998

Who is responsible in the correctness and accuracy of transmitted information content over a data communication?

• A. The channel
• B. The transmitter and receiver
• C. The modem
• D. The bridge

70. ECE Board Exam April 1998

What is meant by the term deviation ratio?

• A. The ratio of the carrier center frequency to the audio modulating frequency
• B. The ratio of the highest audio modulating frequency to the average audio modulating frequency
• C. The ratio of the maximum carrier frequency deviation to the highest audio modulation frequency
• D. The ratio of the audio modulating frequency to the center carrier frequency

71. ECE Board Exam April 1998

A quarter wavelength devices made of crystalline calcite that changes polarization in the optic fiber communication.

• A. Isolator
• B. Retarder
• C. Polarizer
• D. Filters

72. ECE Board Exam April 1998

Known as the maritime communications law which was enacted December 5, 1927

• A. R.A. No. 109
• B. R.A. No. 3396
• C. R.A. No. 7925
• D. R.A. No. 3846

73. ECE Board Exam April 1998

How do you transmit through multiplexing, a thousand of voice channel information over a single fiber optic using one wavelength?

• A. Polar division
• B. Time division
• C. Fiber division
• D. Frequency division

74. ECE Board Exam April 1998

In regulation of public telecommunications carrier such as in the evaluation of new entrant, the following consideration shall be given emphasis to _______.

• A. Legal, technical and citizenship
• B. Technical, citizenship and kind of service
• C. Citizenship, capacity and financial
• D. Technical, legal and financial

75. ECE Board Exam April 1998

One of the following is a high powered RF ac basic transmitter that has two or more stages, the oscillator stage which determines the frequency operation and RF amplifier stage or stages that develop the high power output. The purpose of which is to develop a good frequency stability.

• A. Goldsmith
• B. MOPA
• C. Alexanderson
• D. Hartley

76. ECE Board Exam April 1998

What is the meaning of the term velocity factor of a transmission line?

• A. The index of shielding for coaxial cable
• B. The velocity of the wave on the transmission line multiplied by the velocity of light in vacuum
• C. The ratio of the characteristic impedance of the line to the terminating impedance
• D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum

77. ECE Board Exam April 1998

Which of the following determines the characteristics of a transmission line?

• A. Inductance
• B. Capacitance
• C. Physical dimension
• D. Length

78. ECE Board Exam April 1998

One of the following is among the types of fiber optics used in electronics communication.

• A. Step-index multimode
• B. Graded-index multimode
• C. Semi-graded multimode
• D. Single mode

79. ECE Board Exam April 1998

Which of the following refers to the smallest beam of a satellite antenna’s radiation pattern

• A. Global beam
• B. Spot beam
• C. Zone beam
• D. Hemispheric beam

80. ECE Board Exam April 1998

One of the FM signal generator control which varies the phase of the modulating voltage applied to the oscillator of the sweep generator

• A. Band control
• B. Phase control
• C. Marker amplitude control
• D. Sweep output control

81. ECE Board Exam April 1998

What consists the front-end circuit of a VHF TV superheterodyne receiver?

• A. Mixer, RF amplifier and AFC?
• B. RF amplifier, Band pass filter and mixer
• C. Local oscillator, mixer and RF amplifier
• D. Local oscillator, AGC and antenna

82. ECE Board Exam April 1998

One of the following prevents a transmitter from emitting a signal that interferes with other stations on frequency during the test.

• A. Use of low height antenna
• B. Use of grounded antenna
• C. Use of dummy antenna
• D. Use of shielded antenna radiator

83. ECE Board Exam April 1998

A transmission line consisting of two conductors that have equal resistance per unit length.

• A. Unbalanced line
• B. Open-wire line
• C. Balanced line
• D. Coaxial line

84. ECE Board Exam April 1998

How do you eliminate radio frequency variation of an oscillator transmitter caused by its supply voltage?

• A. Use new power supply
• B. Lossen power supply shielding
• C. Use of regulated power supply
• D. Use of high capacitor in the supply circuit

85. ECE Board Exam April 1998

Which of the following is not common transmission line impedance?

• A. 50 ohms
• B. 120 ohms
• C. 75 ohms
• D. 650 ohms

86. ECE Board Exam April 1998

How do you reduce the loss that is produced when light strikes a flat polished end of a fiber optic?

• A. By painting the surface
• B. By inclining the surface
• C. By cooling
• D. By application of antireflection coating

87. ECE Board Exam April 1998

Best reason for pressurizing waveguides with dry air

• A. To maintain propagation
• B. To maintain temperature of the waveguide
• C. To reduce the possibility of internal arcing
• D. To increase the speed of propagation

88. ECE Board Exam April 1998

What is the device used in fiber optic communication which consist of a receiver transmitter use to clean up and amplify digital data moving in one direction and another in the opposite direction?

• A. Optic compressors
• B. Optic retarders
• C. Optic isolator
• D. Optic regenerators

89. ECE Board Exam April 1998

Which of the following refers to the first active satellite?

• A. Telstar I
• B. Echo I
• C. Intelsat I
• D. Sputnik I

90. ECE Board Exam April 1998

In modulation technique, which of the following is referred to audible pitch?

• A. Width
• B. Frequency
• C. Harmonic
• D. Amplitude

91. ECE Board Exam April 1998

What do you call the phenomenon in digital circuits that describe the duration of time a digital signal passes a circuit?

• A. Transmission time
• B. Elapsed time
• C. Propagation delay
• D. Travel delay

92. ECE Board Exam April 1998

What is the major cause of atmospheric or static noise?

• A. Sunspots
• B. Airplanes
• C. Meteor showers
• D. Thunderstorm

93. ECE Board Exam April 1998

Which of the following is not referred to as data terminal equipment?

• A. Telephone set
• B. Printers
• C. Modem
• D. Computer

94. ECE Board Exam April 1998

_______ is referred as the difference between available power and power budget?

• A. Fade margin
• B. Power margin
• C. Nominal gain
• D. Power dissipation

95. ECE Board Exam April 1998

The conversion of digital signal into analog for purposes of transmitting into the telephone line is done through ______.

• A. ISDN
• C. RS232C
• D. Modem

96. ECE Board Exam April 1998

Refers to the duration occupancy period of call during its use.

• A. Occupancy period
• B. Traffic time
• C. Use time
• D. Holding time

97. ECE Board Exam April 1998

In data communication the transmission of binary signals will require _______.

• A. Same bandwidth as analog
• B. More bandwidth than analog
• C. Less bandwidth than analog
• D. Bigger cable diameter

98. ECE Board Exam April 1998

Assuming a UHF frequency range of 405.0125 MHz to 405.0875 MHz at 25 kHz channeling plan, how many channels can you produce?

• A. 2.5 ch.
• B. 2 ch.
• C. 4 ch.
• D. 3 ch.

99. ECE Board Exam April 1998

One of the following is a possible cause for a slow drift of frequency in a self-exited transmitter oscillator circuits resulting to a poor frequency stability.

• A. Loose shielding
• B. Heating of capacitor in the oscillator
• C. Poor soldered connections
• D. Faulty capacitor, resistor, tubes or resistors

100. ECE Board Exam April 1998

A modulation which does not follow the sine wave pattern, it produces undesirable harmonics such as spurious emission

• A. 0% modulated
• B. Over-modulated
• C. Unmodulated
• D. 100% modulated