This is 100 items set of Practice Examination 11 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 11
Choose the letter of the best answer in each questions.
1. (ECE Board Problem, November 2001)
“Compulsory interconnection”
- a.) EO 59
- b.) EO 546
- c.) EO 109
- d.) Act 3846
2. (ECE Board Problem, November 2002)
A single measuring circuit having a resistor if 10 kΩ is connected in series with a 0.5 μF capacitor. What is affective bandwidth?
- a.) 50 kHz
- b.) 5 Hz
- c.) 50 Hz
- d.) 500 Hz
3. (ECE Board Problem, April 1999)
An aircraft deviation measured by an ILS localizer.
- a.) Altitude
- b.) Ground Speed
- c.) Vertical
- d.) Horizontal
4. (ECE Board Problem, November 2001)
In order to have a maximum power transfer, what must be the relation of the input circuit impedance?
- a.) Equal Impedance
- b.) Infinity
- c.) Zero
- d.) Less Than
5. (ECE Board Problem, November 2001)
The ratio of the speed of the light in vacuum to the speed of the light in a material.
- a.) Index of Refraction
- b.) Dielectric Constant
- c.) Velocity Factor
- d.) Permittivity
6. (ECE Board Problem, November 2001)
What is the radiation pattern of a half – wave dipole?
- a.) Doughnut Shape
- b.) Bi-Directional
- c.) Unidirectional
- d.) Omnidirectional
7. (ECE Board Problem, November 2001)
It is produced when an object travels faster than the speed of sound.
- a.) Shock Wave
- b.) Ultrasound
- c.) Sonic Wave
- d.) Light Wave
8. (ECE Board Problem, November 2001)
The time used for reference for determining the capacity of accepting calls for telephone system.
- a.) 12 MN
- b.) High Usage Hour
- c.) 12NN
- d.) Low Usage Hour
9. (ECE Board Problem, November 2001)
The term used for deafness of higher frequencies due to old age.
- a.) Ear Deafness
- b.) Cortial Deafness
- c.) Tinnitus
- d.) Presbycusis
10. (ECE Board Problem, November 2002)
Single side band emission is most frequently used in what frequency band?
- a.) LF
- b.) HF
- c.) MF
- d.) VLF
11. (ECE Board Problem, November 2001)
A device that converts voice to data.
- a.) Vocoder
- b.) Covoder
- c.) Modern
- d.) Repeater
12. (ECE Board Problem, November 2001)
A microwave device which permits signal only in one direction.
- a.) RF Emitter
- b.) Capacitor
- c.) Varactor and triac
- d.) Ferrite Isolator
13. (ECE Board Problem, November 2001)
A very small band of frequency that is used to protect interference of adjacent frequency.
- a.) Guard
- b.) Carrier
- c.) Modulating
- d.) Tolerance
14. (ECE Board Problem, November 2001)
It is a communication system operation where the receiving station controls the effective data transmission rate at the sending station.
- a.) Pacing
- b.) Polling
- c.) Handshaking
- d.) Contention
15. (ECE Board Problem, November 2001)
Where is the AGC in the IF amplifier derived?
- a.) Mixer
- b.) Rf Amplifier
- c.) Detector
- d.) Local Oscillator
16. (ECE Board Problem, November 2002)
What is the voltage in a line, open terminated at the end, quarter-wavelength from the termination?
- a.) Minimum
- b.) Maximum
- c.) The same
- d.) Increasing
17. (ECE Board Problem, November 2001)
What is the cellular system used in Europe?
- a.) GSM
- b.) TACS
- c.) AMPS
- d.) NMT
18. (ECE Board Problem, November 2001)
Satellite revolution in the same direction as the earth's rotation.
- a.) Retrograde
- b.) Accelerated
- c.) Deccelerated
- d.) Posigrade
19. (ECE Board Problem, November 2001)
What is meant by the term radiation resistance of an antenna?
- a.) The resistance in the trap coils to received signal.
- b.) An equipment resistance that would dissipate the same amount of power as that radiated from an antenna
- c.) The specific impedance of an antenna.
- d.) Losses in the antenna elements and feed line.
20. (ECE Board Problem, November 2001)
How do you connect two digital terminal equipment (DTE) in the absence of a modem?
- a.) Line Bridging.
- b.) Direct connection with the use of a null modem.
- c.) Sharing of line.
- d.) Using a router.
21. (ECE Board Problem, April 2002)
__________ demodulates an FM signal.
- a.) Frequency Discriminator
- b.) Frequency Multiplier
- c.) Diode Detector
- d.) IF Amplifier
22. (ECE Board Problem, April 2000)
The effect of multi mode propagation caused the rays leaving the fiber to interfere constructively and destructively as they leave the end of the fiber, this effect is called ________.
- a.) multi mode Interference
- b.) Modal Delay Spreading
- c.) multi mode Effect
- d.) Single Modal Effect
23. (ECE Board Problem, November 2000)
What is the maximum number of lines for any building other than a one or two story residential building to be required a service entrance facility under ECE building code?
- a.) Two Lines
- b.) Five Lines
- c.) Three Lines
- d.) Not Required
24. (ECE Board Problem, November 2000)
Which of the following is not part of the audio frequency section of the radio transmitter?
- a.) AF Voltage
- b.) Microphone
- c.) Master Oscillator
- d.) AF power Amplifier
25. (ECE Board Problem, November 2000)
Which of the following solution will you prescribed to a telegraph transmitter power supply to avert a chirp?
- a.) Resonate power supply filters.
- b.) Decrease the voltage of power supply.
- c.) Regulate the power supply voltage
- d.) Decrease current output.
26. (ECE Board Problem, April 2000)
What is the term for the ratio of actual velocity at which a signal travels through a line to the speed of light in a vacuum?
- a.) Surge Impedance
- b.) Characteristics Impedance
- c.) Standing Wave Ratio
- d.) Velocity Factor
27. (ECE Board Problem, April 1999)
Which part of the HF marine antenna safety link is intended to be broken during the unusual movement of the ship?
- a.) Halkyard
- b.) Weak Part
- c.) Mainmast
- d.) Foremast
28. (ECE Board Problem, November 2002)
A PCM has a 30 kHz sampling frequency. What is the maximum input frequency?
- a.) 15 kHz
- b.) 60 kHz
- c.) 45 kHz
- d.) 30 kHz
29. (ECE Board Problem, April 1999)
What is the capture effect?
- a.) The weak signal received is the only demodulated signal.
- b.) All signals on a frequency are demodulated by an AM receiver.
- c.) All signals on a frequency are demodulated by an AM receiver.
- d.) The loudest signal received is the only demodulated signal.
30. (ECE Board Problem, April 2000)
Which of the following microwave antenna is normally used when obtaining an omni – directional radiation requirement?
- a.) Grid Type
- b.) Whip
- c.) Bicone
- d.) Parabolic
31. (ECE Board Problem, April 1999)
What is being measured in RADAR theory to complete the determination of a distance to a target or an object, after a high radio frequency signal is transmitted to a target?
- a.) Transmission time from the source to target.
- b.) Transmission time from target back to source.
- c.) Echo time of the object to the source.
- d.) Complete signal transmission from source and back.
32. (ECE Board Problem, April 2000)
What is the radio horizon distance between a 150 ft. transmitting station and a 70 ft. receiving station?
- a.) 82.46 mi
- b.) 82.46 km
- c.) 29.15 km
- d.) 29.15 mi
33. (ECE Board Problem, November 2000)
Telephone channel has a band-pass characteristics occupying the frequency range of _____.
- a.) 300 – 2700 Hz
- b.) 300 – 3400 Hz
- c.) 300 – 3000 Hz
- d.) 300 – 400 Hz
34. (ECE Board Problem, November 1999)
This the Nordic analogue mobile radio telephone system originally used in Scandinavia.
- a.) NMT
- b.) GSM
- c.) PCN
- d.) PCS
35. (ECE Board Problem, April 2000)
When a signal bandwidth of a TV broadcast over the radio is lessen, using a technique that limits a picture frequency, this is referred to as ________.
- a.) Video Control
- b.) Interlaced Scanning
- c.) Demodulation
- d.) Line Scanning
36. (ECE Board Problem, April 1999)
These are bend of light wavelengths that are too short to be seen by the human eye.
- a.) Visible
- b.) Amber
- c.) Infrared
- d.) Ultraviolet
37. (ECE Board Problem, April 2000)
How does the length of the director element of a parasitic element beam antenna compare with that of the driven element?
- a.) It is about 5% longer.
- b.) It is one-half as long.
- c.) It is twice as long.
- d.) It is about 5% shorter.
38. (ECE Board Problem, November 2001)
Refers to the numeric ratio relating to the radiated signal strength of an antenna to that of another antenna.
- a.) Antenna Loss
- b.) Antenna Gain
- c.) Antenna Bandwidth
- d.) Antenna Efficiency
39. (ECE Board Problem, November 2001)
What will happen if there is a great mismatch between the load and the source?
- a.) High SWR
- b.) Low SWR
- c.) Medium SWR
- d.) SWR of 1
40. (ECE Board Problem, November 2001)
What is used to connect a computer if it is far from the host?
- a.) Modem
- b.) AVR
- c.) Waveguide
- d.) Transponder
41. (ECE Board Problem, November 2001)
Range of frequency that an antenna will perform well.
- a.) Antenna Bandwidth
- b.) Antenna Beamwidth
- c.) Antenna Efficiency
- d.) Antenna Directivity
42. (ECE Board Problem, November 2001)
What is the fastest memory of a computer?
- a.) RAM
- b.) Cache
- c.) Magnetic Disk
- d.) Magnetic Tape
43. (ECE Board Problem, November 2001)
What composes the electromagnetic waves?
- a.) Electric and Magnetic Field
- b.) Acoustic and Water Wave
- c.) Current and Voltage
- d.) Pressure and Frequency
44. (ECE Board Problem, November 2001)
One of the characteristics of an early facsimile machine which electromechanical device.
- a.) Receive start/stop bits to synchronize.
- b.) Using heat that would burn the image into heat.
- c.) Using tubes to amplify the signal.
- d.) Using fire to heat the thermal paper.
45. (ECE Board Problem, November 2001)
What is the cable requirement for one or two-storey building that has more than five telephone lines?
- a.) Service Entrance
- b.) Service Cable
- c.) Building Cable
- d.) Residential Cable
46. (ECE Board Problem, November 2001)
A transmission line consisting of center conductor, a plastic insulation, a fine wire braid shield and outer plastic insulation as a jacket.
- a.) coaxial cable
- b.) twin cable
- c.) wave guide
- d.) twisted pair
47. (ECE Board Problem, November 2001)
The executive branch of government in-charge of policy making in telecommunication.
- a.) National Telecommunication Commission
- b.) Telecommunication Control Bureau
- c.) Department of Transportation and Communication
- d.) Bureau of Communication
48. (ECE Board Problem, November 2001)
What is the dBSPL of an auditorium with contemporary music?
- a.) 95 – 100 dB
- b.) 40 – 50 dB
- c.) 50 – 60 dB
- d.) 70 – 80 dB
49. (ECE Board Problem, November 2001)
What is the symbol designated for a frequency modulated carrier for a single telephony transmission?
- a.) F3E
- b.) F3F
- c.) G3F
- d.) G3E
50. (ECE Board Problem, November 2001)
The layer that is responsible for sky wave propagation and the highest layer?
- a.) D
- b.) F2
- c.) A
- d.) E
51. (ECE Board Problem, November 2001)
Process of impressing lower intelligent frequency to higher frequency.
- a.) modulation
- b.) detection
- c.) multiplexing
- d.) scrambling
52. (ECE Board Problem, November 2001)
Find the suitable ground plane for a frequency of 220 MHz.
- a.) 0.5 m
- b.) 0.24 m
- c.) 0.34 m
- d.) 1.2 m
53. (ECE Board Problem, November 2001)
The term used for the mechanism RADAR searching for an object.
- a.) scanning
- b.) tracing
- c.) lobing
- d.) nodding
54. (ECE Board Problem, November 2001)
- a.) variable capacitance
- b.) variable resistance
- c.) variable inductance
- d.) piezoelectric effect
55. (ECE Board Problem, November 2001)
What do you call the telephone system connecting residence and business establishments?
- a.) Public Telephone System
- b.) Pay Phone System
- c.) Private Network System
- d.) Touch Tone System
56. (ECE Board Problem, April 2000)
In Broadcasting, an area characterized to have no interference but wit fading or intermittent variations in intensity is _______.
- a.) Primary Service Area
- b.) Intermediate Service Area
- c.) Tertiary Service Area
- d.) Secondary Service Area
57. (ECE Board Problem, April 2002)
Information capacity is proportional.
- a.) bandwidth
- b.) noise
- c.) power
- d.) flux
58. (ECE Board Problem, April 2002)
What is the number of lines per field in an NTSC TV?
- a.) 525
- b.) 262.5
- c.) 625
- d.) 312.5
59. (ECE Board Problem, April 2002)
It refers to the time required for a signal to complete one cycle.
- a.) Wavelength
- b.) Frequency
- c.) Amplitude
- d.) Period
60. (ECE Board Problem, April 2002)
What happens when the separation between two conductors having the same diameter decreases?
- a.) The characteristic impedance decreases.
- b.) The characteristic impedance increases,
- c.) The characteristic impedance does not change.
- d.) Cannot be determined
61. (ECE Board Problem, November 2001)
The government entity that regulates the cable television industry in the Philippines.
- a.) Executive Commission
- b.) House of Representatives
- c.) NTC
- d.) DOTC
62. (ECE Board Problem, November 2001)
A modulation which is amplitude modulated that consist of recurrent pulses.
- a.) PAM
- b.) PWM
- c.) PPM
- d.) AM
63. (ECE Board Problem, November 2001)
Which of the following consist of two of the three primary colors in television signal? a.) red, b) violet,c) yellow, and d) blue.
- a.) a and b
- b.) b and c
- c.) c and d
- d.) a and d
64. (ECE Board Problem, November 2001)
Which of the navigational equipment which utilizes the principle of RADAR but is use in underwater?
- a.) TACAN
- b.) SONAR
- c.) TASI
- d.) RADAR
65. (ECE Board Problem, November 2001)
How can cross – modulation in a receiver be reduced?
- a.) Adjust the pass band tuning.
- b.) Increase RF amplifier gain and decrease AF amplifier gain
- c.) Installing a filter at the receiver
- d.) Using a better antenna
66. (ECE Board Problem, November 2001)
The circuit that convert signal in order that it can be fed to the medium suitable for transmission.
- a.) Modulator
- b.) Mixer
- c.) Receiver
- d.) Transmitter
67. (ECE Board Problem, November 2001)
A type of Class C amplifier which has 1 to 10 times the gain of input used to generate frequency multiple of the fundamental frequency.
- a.) Frequency Generator
- b.) Frequency Multiplier
- c.) Frequency Amplifier
- d.) Frequency Divider
68. (ECE Board Problem, November 2001)
The definition of modulation index:
- a.) The radio of deviation frequency and modulating
- b.) The ratio of the maximum deviation frequency and maximum modulating frequency
- c.) The ratio of actual deviation to the maximum deviation
- d.) The ratio of the maximum deviation to the actual deviation
69. (ECE Board Problem, November 2001)
One of the following can be best attained by a trap antenna in radio communication?
- a.) Increase transmitter gain
- b.) Directionality
- c.) Effective filter to noise signal
- d.) Multi frequency band operation
70. (ECE Board Problem, November 2000)
When we talk of the study of acoustics, a sound is considered _____wave.
- a.) Circular
- b.) Light
- c.) Laser
- d.) Longitudinal
71. (ECE Board Problem, November 1999)
One of the major components required under the global maritime distress and safety system.
- a.) Provision of Morse code
- b.) Provision of radio telegraph operator
- c.) Provision of facsimile
- d.) Provision of radio personnel
72. (ECE Board Problem, November 1999)
A resultant effect in launching a satellite from the earth caused by both forward motion away from the earth that produces inertia tending the satellite to travel in straight line upwards and the gravitational pull towards the earth is referred to as _______.
- a.) Centripetal acceleration
- b.) Gravity
- c.) Weight of satellite
- d.) Satellite Speed
73. (ECE Board Problem, April 2000)
A RADAR set receiver has normally a ________ mixer stage.
- a.) Tunnel diode
- b.) FET
- c.) Class A
- d.) Silicon Crystal
74. (ECE Board Problem, April 1999)
Refers to a connector that normally connects RG – 213 coaxial cable to an HF transceiver.
- a.) N-type Cable
- b.) F-type Cable
- c.) PL-259
- d.) BNC
75. (ECE Board Problem, November 2000)
Which of the following refers to the bandwidth of optical fiber?
- a.) 1 Hz – 30,000 Hz
- b.) 1 kHz – 300 kHz
- c.) 1MHz – 300 MHz
- d.) 1MHz – 500MHz
76. (ECE Board Problem, April 1999)
How many commissioners does the National Telecommunications Commission have?
- a.) 1
- b.) 5
- c.) 3
- d.) 2
77. (ECE Board Problem, November 2000)
Which one is referred to the reduction of receiver gain caused by strong signal from nearby transmission of adjacent frequency?
- a.) Intermodulation
- b.) Quieting
- c.) Fading
- d.) Desensitizing
78. (ECE Board Problem, April 2000)
Transmission of information through a communication modem is intended to transmit digital information over which of the following type of communication medium?
- a.) Digital
- b.) Hybrid
- c.) Radio
- d.) Analog
79. (ECE Board Problem, April 1999)
Determine from the following an advantage using a trap antenna.
- a.) It has directivity in the high frequency bands.
- b.) Can be used for multiband operation.
- c.) Minimizes harmonic radiation.
- d.) Has high gain.
80. (ECE Board Problem, November 2002)
What do you call a circuit in PCM wherein the instantaneous sinusoidal wave is regular sample and converted to a discrete amplitude levels?
- a.) analog to digital converter
- b.) sample and hold
- c.) modem
- d.) multiplexer
81. (ECE Board Problem, April 1999)
Determine from the following, possible cause for a slow drift of frequency in self-excited transmitter oscillator circuits resulting to poor frequency stability.
- a.) Faulty capacitors, resistors, tubes or transistors.
- b.) Loose shielding.
- c.) Heating in the oscillator device causing a change in electrical characteristics.
- d.) Loose connections in the oscillator, amplifier or antenna circuits.
82. (ECE Board Problem, November 2000)
Which of the following penalty is provided under the existing telecommunications law, should an international carrier unable to comply with its obligation to provide local exchange service in un-served and underserved areas within three years from grant of authority?
- a.) Financial penalty in accordance with existing schedules.
- b.) Cancellation of its authority.
- c.) Given one year to comply.
- d.) Given two years to comply.
83. (ECE Board Problem, April 2000)
In basic transmitter such as CW transmission, the rounding off of square wave emission will reduce________.
- a.) Reach
- b.) Voltage
- c.) Bandwidth
- d.) Transmitter power
84. (ECE Board Problem, November 1999)
Refers to one possible cause for an abrupt frequency variation in a self-excited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant oscillation.
- a.) Poor soldered connections.
- b.) Heating of capacitor in the oscillator.
- c.) DC and RF ac heating of resistors, which cause change in values.
- d.) Aging which cause change condition in parts characteristics.
85. (ECE Board Problem, November 2000)
Which of the following is referred to the SYN character of ASCII code?
- a.) 32H
- b.) 16H
- c.) 64H
- d.) 8H
86. (ECE Board Problem, November 1999)
In a basic radio transmitter, what is the main disadvantage of a single-tube transmitter?
- a.) Frequency Instability
- b.) Non-portable
- c.) Heating Effect
- d.) Bulky
87. (ECE Board Problem, April 2000)
One of the following is considered the largest source of signal power loss in the use of fiber optic as a communication medium such as due to misalignment.
- a.) Bending
- b.) Scattering
- c.) Connection
- d.) Absorption
88. (ECE Board Problem, November 2000)
Statement, which best describe a mixing process in radio communication.
- a.) Process of eliminating noise through phase differentiation.
- b.) Producing sum and difference of two frequencies from a combination of two signals.
- c.) Processing of eliminating noise through phase comparison.
- d.) Combination of two signals to form three or more output signals.
89. (ECE Board Problem, November 2001)
What is the input impedance equivalent of an open-ended transmission line which is longer than a quarter wavelength?
- a.) Open equivalent
- b.) Equivalent to reactive circuit
- c.) As resistive equivalent
- d.) As pure inductor
90. (ECE Board Problem, November 2000)
How would you isolate data communications faults in a basic error determination technique?
- a.) Test each cards.
- b.) Simulate the loop.
- c.) Test each repeater.
- d.) Carry out loopback test.
91. (ECE Board Problem, April 2000)
Which of the following describes its system services control point, logical units and physical units as network addressable units in a data network?
- a.) Digital Network Architecture
- b.) Internetworking
- c.) Interconnection Point
- d.) System Network Architecture
92. (ECE Board Problem, November 2000)
A telecommunications law that deregulates the paging services in the country.
- a.) E. O. 125
- b.) Act 3846
- c.) Act 3396
- d.) R.A. 7925
93. (ECE Board Problem, April 2000)
What refers to breaking up the data into blocks with some bounded size?
- a.) Framing
- b.) Segmentation
- c.) Encapsulation
- d.) Packing
94. (ECE Board Problem, November 2001)
What is the apogee of a geosynchronous satellite’s temporary orbit before be placed in the geosynchronous orbit?
- a.) 50,000 mi
- b.) 40,000 mi
- c.) 22,300 mi
- d.) 30,000 mi
95. (ECE Board Problem, November 2001)
A device used in television broadcast that prevents any FM signal from entering into the visual transmitter and vice versa.
- a.) Duplexer
- b.) Mixer
- c.) Diplexer
- d.) Synchronizer
96. (ECE Board Problem, November 1999)
A sound intensity that could cause painful sensation in the human ear.
- a.) Threshold of Sense
- b.) Threshold of Pain
- c.) Hearing Threshold
- d.) Sensation Intensity
97. (ECE Board Problem, April 1999)
What is the first symbol of radio signal emission having an amplitude modulated main carrier single sideband suppressed carrier?
- a.) C
- b.) A
- c.) J
- d.) H
98. (ECE Board Problem, November 1999)
What us the baseband frequency of standard FDM basic super group?
- a.) 300 to 600 kHz
- b.) 312 to 552 kHz
- c.) 60 to 2540 kHz
- d.) 60 to 180 kHz
99. (ECE Board Problem, November 1999)
Very High (radio) Frequency in the spectrum refers to _______ waves.
- a.) Centimetric
- b.) Hectometric
- c.) Kilometric
- d.) Metric
100. (ECE Board Problem, April 1999)
What wave trap frequency is used in the video amplifier?
- a.) 39.75 MHz
- b.) 41.25 MHz
- c.) 4.5 MHz
- d.) 47.25 MHz
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