MULTIPLE CHOICE
QUESTIONS
IN
ELECTRONICS SYSTEMS AND
TECHNOLOGIES (EST)
Digital and Data Communications
MELVIN C. ARCEO, ECE
PERC DC
1. It is defined as knowledge or intelligence
that is communicated between two or more
points.
a. Carrier
b. Sideband
c. Information
d. Broadband
2. What is the category of data transmission if
the binary pulse is maintained for the entire
bit time?
a. Return to zero
b. Bipolar
c. Unipolar
d. Non – return to zero
3. Which medium is the most widely used in
LANs?
a. Twin Lead
b. Fiber – optic cable
c. Twisted Pair
d. Coax
4. These are used for transmission of PCM
encoded time – division multiplexed digital
signal.
a. I carriers
b. E carriers
c. A carriers
d. T carriers
5. Which of the following is not a typical FDM
application?
a. Telemetry
b. Stereo broadcasting
c. Telephone
d. Secure communications
6. A LAN device that is used to interconnect
two networks that use different protocols
and formats.
a. Gateways
b. Routers
c. Bridges
d. Hubs
7. A pulse modulation technique as the width
of a constant amplitude pulse is varied
proportional to the amplitude of the analog
signal at the time the signal is sampled.
a. Pulse Width Modulation
b. Pulse Length Modulation
c. Pulse Duration Modulation
d. All of these
8. The FDM telephone systems accommodate
many channels by
a. Increasing the multiplexer size
b. Using many final carriers
c. Narrowing the bandwidth of each
d. Using
multiple
levels
of
multiplexing
9. It is the transmittal of digitally modulated
analog signals (carrier) between two or more
points in a communications system.
a. Digital modulation
b. Digital transmission
c. Data communications
d. Pulse modulation
10. Indicate which of the following systems is
digital.
a. Pulse-position modulation
b. Pulse-code modulation
c. Pulse–width modulation
d. Pulse-frequency modulation
11. Classification of protocol that interprets a
frame of data as a group of successive bit
combined into predetermined pattern of
fixed length, usually 8 bits each.
a. Character-oriented protocols
b. Byte-oriented protocols
c. Bit-oriented protocols
d. Character and Byte-oriented
protocols
12. Dividing the data block by a constant
produces a remainder that is used for error
detection. It is called the
a. Vertical redundancy check
b. Horizontal redundancy check
c. Block check character
d. Cyclic redundancy check
13. Which of the following is not a benefit of
spread spectrum?
a. Jam – proof
b. Security
c. Immunity of fading
d. Noise proof
14. Converting analog signals to digital is done
by sampling and ___________.
a. Quantizing
b. Companding
c. Pre – emphasis
d. Mixing
15. It is a process of converting an infinite
number of possibilities to a finite number of
conditions.
a. Sampling
b. Coding
c. Quantization
d. Aliasing
16. In T1, it is equal to the reciprocal of the
sample rate
a. Slot Time
b. Transmission time
c. Frame time
d. Bit rate
17. What is the final output of a multiplexer?
a. Baseband
b. Composite baseband
c. Information
d. Composite carrier
18. The baud rate
a. is always equal to the bit transfer rate
b. is equal to twice the bandwidth of
an ideal channel
c. is not equal to the signaling rate
d. is equal to one – half the bandwidth
of an ideal channel
19. Bit errors in data transmission are usually
caused by
a. equipment failures
b. typing mistakes
c. noise
d. poor S/N ratio at receiver
20. A digital modulation technique which is a
form of constant – amplitude angle
modulation similar to standard frequency
modulation except the modulating signal is
binary signal that varies between two
discreet voltage levels.
a. QAM
b. ASK
c. PSK
d. FSK
21. Start and stop bits, respectively, are
a. Mark, space
b. Space, mark
c. Space, space
d. Mark, mark
22. It is the processing of analog signals using
digital methods and includes band limiting
and signals with filters, amplitude
equalization, and phase shifting
a. Digital communications
b. Digital Signal Processing
c. Data communications
d. Carrier recovery method
23. It is a network access method used primarily
with LANs configured in a ring topology
using either baseband or broadband
transmission formats
a. Ethernet
b. Token passing
c. Token ring
d. Token bus
24. A small telephone switching system that can
be used as a LAN is called
a. Ring
b. WAN
c. UART
d. PBX
25. The most common method used for
sampling voice signals in PCM systems
a. unnatural sampling
b. flat top sampling
c. natural sampling
d. free sampling
26. In PCM, it converts the PAM sampled to
parallel PCM codes
a. Analog-to-Digital converter
b. Digital-to-analog converter
c. Pre-emphasis circuit
d. Compander
27. The OSI layer that provides the control
functions necessary to establish, manage and
terminated the connections as required to
satisfy the user request.
a. Application layer
b. Network layer
c. Session layer
d. Physical layer
28. In PAM demultiplexing, the receiver clock
is derived from
a. standard radio station WWV
b. a highly accurate internal oscillator
c. the PAM signal itself
d. the 60 Hertz power line
29. It is also known as digital modulation
a. Digital transmission
b. Digital sampling
c. Digital radio
d. Data transmission
30. Time – division multiplex
a. can be used with PCM only
b. combines five groups into
supergroup
c. stacks 24 channels in adjacent
frequency slots
d. interleaves pulses belonging to
different transmissions
31. It is a numerical indication of how
efficiently a PCM code is utilized
a. Coding efficiency
b. Companding
c. Pre-emphasis
d. Dynamic Range
32. Type of PCM which is designed to take
advantage
of
the
sample-to-sample
redundancies in the typical speech
waveform
a. Single – bit PCM code
b. Pulse Code Modulation
c. Differential PCM
d. Delta modulation
33. The Basic Rate Interface (BRI) of ISDN has
a total bit rate of _____.
a. 192 kbps
b. 148 kbps
c. 64 kbps
d. 1.544 Mbps
34. A form of angle – modulated, constant
amplitude digital modulation similar to
conventional phase modulation except its
input is binary digital signal and there are
limited numbers of output phase possible.
a. ASK
b. PSK
c. FSK
d. QAM
35. The main circuit in a PSN generator is ____.
a. XOR
b. Multiplexer
c. Shift register
d. Mixer
36. The circuit that performs demultiplexing in
an FDM system is _____.
a. Op - Amp
b. Bandpass filter
c. Discriminator
d. Subcarrier oscillator
37. __________ defines how a user gets control
of the channel so as to allow transmission.
a. channel access
b. collision detection
c. collision avoidance
d. carrier sense
38. The fastest LAN topology is the
a. ring
b. bus
c. star
d. square
39. It is a the symmetrical expectation of the bit
error rate in the system
a. probability of errors
b. error detection
c. error control
d. bit error rate
40. It is simply the data rate at which serial
PCM bits are clocked out of the PCM
encoder onto the transmission line.
a. line speed
b. baud rate
c. output rate
d. bit rate
41. A quantizing is _______.
a. Multiplexer
b. Demultiplexer
c. A/D converter
d. D/A converter
42. Refers to the rate of change of a signal on a
transmission medium after encoding and
modulation have occurred
a. baud rate
b. phase shift
c. bit rate
d. frequency deviation
43. The magnitude difference between adjacent
steps in quantization is called __________.
a. Quantum
b. Step size
c. Resolution
d. Any of these
44. It is a set of rules implementing and
governing an orderly exchange of data
between layers of two devices, such as line
control units and front – end processors.
a. Data Link Protocol
b. Network Protocol
c. Point to Point Protocol
d. File Transfer Protocol
45. A signaling system in which each letter of
the alphabet is represented by a different
symbol is not used because
a. it would be too difficult for an
operator to memorize
b. it is redundant
c. noise would introduce too many
errors
d. too many pulses per letter are
required
46. A modulation process that involves
conversion of a waveform from analog to
digital form by means of coding.
a. PDM
b. PCM
c. PLM
d. PAM
47. What is the bandwidth required to transmit
at a rate of 10 Mbps in the presence of a 28bd S/N ratio?
a. 1.075 MHz
b. 10 Mhz
c. 5 Mhz
d. 10.5 Mhz
48. The slope of the analog signal is greater than
the delta modulator can maintain
a. overload distortion
b. granular noise
c. slope overload
d. peak limiting
49. A scheme in which several channels are
interleaved and then transmitted together is
known as
a. Frequency division multiplex
b. Time division multiplex
c. a group
d. a supergroup
50. The best frequency demodulator is the
a. PLL discriminator
b. Pulse-averaging discriminator
c. Foster-Seeley discriminator
d. Radio detector
51. What property distinguishes digital radio
systems
from
conventional
analog
communications system?
a. the type of carrier used in the
transmission of data
b. the nature of the modulating signal
c. the type of modulation of data to be
used
d. the nature of the transmitter and
receiver to be used
52. The circuit switch is a _______ switch.
a. See – through
b. Transparent
c. Vague
d. Opaque
53. A carrier recovery is needed with
a. FSK
b. BPSK
c. DPSK
d. QAM
54. The Hartley – Shannon theorem sets a limit
on the
a. highest frequency that may be sent
over a given channel
b. maximum capacity of a channel
with a given noise level
c. maximum number of coding levels
in a channel with a given noise level
d. maximum number of quantizing
levels in a channel of a given
bandwidth
55. The phase relationship between signaling
elements for BPSK is the optimum signaling
format and occurs only when two binary
signal levels are allowed and when one
signal is the exact negative of the other.
a. Antipodal signaling
b. Carrier recovery
c. Squaring loop
d. Phase referencing
56. Pulse – amplitude modulation signals are
multiplexed by using
a. Subcarrier
b. Bandpass filters
c. A/D converters
d. FET switches
57. It is the ratio of the transmission bit rate to
the minimum bandwidth required for a
particular modulation scheme.
a. Bandwidth efficiency
b. All of these
c. Information density
d. Spectral efficiency
58. Ethernet is baseband transmission system
designed by _____.
a. Thomas Murray and Robert Metcalfe
b. David Boggs and Thomas Murray
c. Thomas Murray and Emile Baudot
d. Robert Metcalfe and David Boggs
59. It is a system where the digital signals are
placed directly on the coaxial cable.
a. Broadband
b. Baseband
c. CSMA/CD
d. Token ring
60. A basic group B
a. Occupies the frequency range
from 60 to 108 kHz
b. Consists of erect channels only
c. Is formed at the group translating
equipment
d. Consists of 5 supergroups
61. Which of the following is not primarily type
of data communications?
a. a telephone
b. teletype
c. telegraph
d. CW
62. Packets which is self – contained and travels
through the network independent of other
packets of the same message by whatever
means available.
a. Packet
b. Frame
c. Datagram
d. Data
63. Transmitting the data signal directly over the
medium is referred to as
a. baseband
b. broadband
c. ring
d. bus
64. The main reason that serial transmission is
preferred to parallel transmission is that?
a. serial is faster
b. serial requires only a single channel
c. serial requires multiple channels
d. parallel is too expensive
65. Which of the following is not a LAN?
a. PBX system
b. Hospital system
c. Office building system
d. Cable TV system
66. A modulation technique where data rates in
excess of 56 kbps can be achieved over
telephone circuits
a. ASK
b. Trellis Code Modulation
c. GSK
d. Any of these
67. It is how the primary designates the
secondary as the designation of recipient of
data.
a. Line turnaround
b. Selection
c. Line control
d. Control Protocol
68. It is the process of compressing and
expanding and is a means of improving the
dynamic range of communications system.
a. Pre-emphasis
b. Filtering
c. De-emphasis
d. Companding
69. The supergroup pilot is
a. applied to each multiplexing bay
b. used to regulate the gain of
individual repeaters
c. applied at each adjustable equalizer
d. fed in at a GTE
70. The time it takes to transmit one TDM frame
is called _________.
a. Slot time
b. Frame time
c. Transmission time
d. Any of these
71. It is the thermal noise power normalized to
1-Hz bandwidth
a. power density ratio
b. thermal noise
c. noise power density
d. ambient temperature noise
72. It is the procedure used to decide which
device has the permission to transmit at any
given time
a. Flow control
b. Sequence control
c. Line control
d. Framing
73. Any rounded – off errors in the transmitted
signal are reproduced when the code is
converted back to analog in the receiver.
a. Aperture error
b. Quantization error
c. Aperture distortion
d. Slope overload
74. The biggest disadvantage of PCM is
a. its inability to handle analog signals
b. the high error rate which is
quantizing noise introduces
c. its incompatibility with TDM
d. the large bandwidths that are
required for it
75. T1 stands for
a. Transmission one
b. Telecommunication one
c. Telex one
d. Transmission line one
76. Involves compression in the transmitter
after the input sample has been converted to
a linear PCM code and then expansion in the
receiver prior to PCM coding
a. analog companding
b. A – law companding
c. Digital companding
d. U – law companding
77. Mark and space refer respectively to
a. dot and dash
b. message and interval
c. binary 1 and binary 0
d. on and off
78. Variation of biphase that is used for
encoding SMPTE time code data and for
recording on video tapes
a. Biphase - M
b. B8Z
c. Manchester
d. UPNRZ
79. Pulse width modulation may be generated
a. by differentiating pulse position
modulation
b. with a monostable multivibrator
c. by integrating the signal
d. with a free running multivibrator
80. The ISDN channel D designates _____
which contains control information.
a. Data
b. Flow
c. Control
d. Bearer
81. A transmission of binary data which
involves the transmission of two non – zero
voltage level
a. Unipolar
b. Polar
c. Bipolar
d. Non – return to zero
82. Switching systems
a. improve the efficiency of data
transfer
b. are not used in data systems
c. require additional lines
d. are limited to small data networks
83. It involves converting standard logic levels
to a form more suitable to telephone
transmission lines
a. Transmission line encoding
b. Physical line encoding
c. Digital line encoding
d. Multiplexing
84. The primary advantage
transmission
a. economical
b. reliability
c. noise immunity
d. efficiency
of
digital
85. Part of the PCM system that prevents
aliasing or foldover distortion
a. Bandpass filter
b. Anti – foldover distortion
c. Anti – aliasing
d. Any of these
89. An IC that contains A/D and D/A
converters, companders, and parallel-toserial converters is called a
a. Codec
b. Data converter
c. Multiplexer
d. Modem
90. Data communications
transmission of
a. voice
b. video
c. computer data
d. all of the above
refers
to
the
91. The number of amplitude, frequency, or
phase changes that take place per second is
known as the
a. data rate in bits per second
b. frequency of operation
c. speed limit
d. baud rate
92. The basic modulator and demodulator
circuits in PSK are
a. PLLs
b. Balanced modulators
c. Shift registers
d. Linear summers
86. It is defined as the process of transforming
messages or signals in accordance with a
definite set of rules.
a. Quantizing
b. Sampling
c. Coding
d. Decoding
93. What is the result if the input of ADC is
changing while performing conversion?
a. Aperture error
b. Overload distortion
c. Aliasing
d. Aperture distortion
87. The PCM code for each channel occupies a
fixed time slot called
a. Frame time
b. Baud
c. Transmission time
d. Epoch
94. Information capacity is convenient
express as
a. baud
b. bits
c. dot length
d. bits per second or bps
88. The building block of a parity or BCC
generator is _________.
a. Shift register
b. XOR
c. 2 – to – 4 level converter
d. UART
95. Which
noise?
a.
b.
c.
d.
to
medium is the least susceptible to
twin lead
fiber – optic cable
twisted pair
coax
96. The RS – 232 interface
a. interconnects data sets and the
transmission circuits
b. uses several different connectors
c. permits custom wiring of signal lines
to the connector pins as desired
d. all of the above
97. The ISDN channel B designates _________.
a. Bearer
b. Data
c. Control
d. Flow
98. Data transmission of the character at a time
with start and stop bits is known as what
type of transmission?
a. asynchronous
b. serial
c. synchronous
d. parallel
99. Sampling technique that when the tops of
the sample pulses retain their natural shape
during the sample interval
a. unnatural sampling
b. flat top sampling
c. natural sampling
d. free sampling
100. A modem converts
a. Analog signals to digital
b. Digital signals to analog
c. Digital signals to analog and viceversa
d. None of these
101. It is a large scale integration chip designed
for use in telecommunication industry for
private branch exchanges, central office
switches, digital handsets and digital echo
suppressors.
a. Vocoder
b. Modem
c. Codec
d. Muldem
102. What is the type of mastergroup used for
low – capacity microwave systems?
a. A600
b. U600
c. L600
d. L400
103. An FDM hierarchy which is formed by
frequency – division multiplexing five
groups containing 12 channels each for a
combined bandwidth of 240 kHz.
a. Supergroup
b. Group
c. Mastergroup
d. Jumbogroup
104. The result whenever the sampling rate is
less than twice the highest audio frequency
a. peak limiting
b. overload distortion
c. alias
d. quantizing noise
105. The most critical and difficult part of
receiving a direct – sequence spread
spectrum signal is
a. Frequency synthesis
b. Synchronism
c. PSN code generation
d. Carrier recovery
106. An FDM hierarchy which is formed by
frequency – division multiplexing 10 super
groups together for a combined capacity
of 600 voice band message channels
a. Supergroup
b. Group
c. Mastergroup
d. Jumbogroup
107. It is the transmittal of digital signals
between to or more points in a
communication system.
a. Digital transmittal
b. Digital communications
c. Digital radio
d. Data communications
108. It is logically equivalent to making
telephone call through the DDD network
except no direct end-to-end connection is
made
a. Normal call
b. Completed call
c. Logical call
d. Virtual call
109. It is proposed network designed by major
telephone companies in conjunction with
the ITU-T with the intent of providing
worldwide telecommunications support for
voice, data, video and facsimile
information within the same network
a. ISDN
b. Broadband communications
c. ATM
d. Ethernet
110. Full duplex operation
a. requires two pair of cables
b. can transfer data in both directions at
once
c. requires modems at both ends of the
circuit
d. all of these
111. The
most
widely
communications code is
a. Morse code
b. ASCII
c. Baudot
d. EBCDIC
used
data
112. Ten bit error occurs in two million
transmitted. The bit error rate is
a. 2 x 10^-5
b. 5 x 10^-5
c. 5 x 10^-6
d. 2 x 10^-6
113. It is a type of FSK where the mark and
space frequencies are synchronized with
the input binary rate
a. QFSK
b. GFSK
c. CPFSK
d. GSK
114. A form of digital modulation similar to
PSK except the digital information is
contained in both the amplitude and the
phase of the transmitted carrier.
a. ASK
b. FSK
c. QAM
d. PSK
115. For the 16-PSK and a transmission system
with a 10kHz bandwidth, determine the
maximum bit rate
a. 40,000 bps
b. 80,000 bps
c. 20,000 bps
d. 16,000 bps
116. It is an empirical record of a system’s
actual bit error performance.
a. probability of error
b. error detection
c. error control
d. bit error rate
117. It is a function of the carrier-to-noise
power ratio and the number of possible
encoding conditions used
a. probability of error
b. error detection
c. error control
d. bit error rate
118. It is used to compare two or more digital
modulation systems that use different
transmission rates, modulation scheme or
encoding techniques
a. Energy per b it-to-noise power
density ratio
b. Noise power density
c. Power density ratio
d. Carrier-to-noise ratio
119. Indicate which of the following is not a
binary code
a. Morse
b. Baudot
c. CCITT-2
d. ARQ
120. To permit the selection of 1 out of 16
equiprobable events, the number of bits
required is
a. 2
b. log 16 base 10
c. 8
d. 4
121. The type of modulation most often used
with direct-sequence spread spectrum is
a. QAM
b. SSB
c. FSK
d. PSK
122. Indicate the false statement. In order to
combat noise,
a. the channel bandwidth may be
increased
b. redundancy may be used
c. the transmitted power may be
increased
d. the signaling rate may be reduced
123. Which of the following is not commonly
used method of error detection?
a. Parity
b. BCC
c. CRC
d. redundancy
124. Quantizing noise occurs in
a. time-division multiplex
b. frequency-division multiplex
c. pulse-code modulation
d. pulse-width modulation
125. In order to reduce quantizing noise, one
must
a. increase the number of standard
amplitudes
b. send pulses whose sides are more
nearly vertical
c. use an RF amplifier at the receiver
d. increase the number of samples per
second
126. Companding is used
a. to overcome quantizing noise in
PCM
b. in PCM transmitters, to allow
amplitude limiting in the receiver
c. to protect small signals in PCM
form quantizing distortion
d. in PCM receivers, to overcome
impulse noise
127. Transmitting data as serial binary word is
called _______.
a. digital communications
b. quantizing
c. PAM
d. PCM
128. Emphasizing low-level signals and
compressing higher level signals is called
a. quantizing
b. companding
c. pre-emphasis
d. sampling
129. Which circuit is most common to both
frequency-hopping and direct-sequence
spread spectrum transmitters?
a. correlator
b. frequency synthesizer
c. PSN code generator
d. Sweep generator
130. One of the most important aspect of any
communication system because it is costly
and limited
a. bandwidth
b. equipments
c. time
d. personnel
131. It consist essentially of sampling analog
information signals and then converting
those samples into discreet pulses of
transporting the pulses from the source to
destination over a physical transmission
medium
a. Pulse modulation
b. Amplitude modulation
c. Frequency modulation
d. Digital modulation
132. He is credited with inventing PCM in 1937
a. N. S. Kapany
b. A. H. Reeves
c. E. H. Alpine
d. A. C. S. Van Heel
133. Data communications uses
a. Analog methods
b. Digital methods
c. All of these
d. None of these
134. An integrated circuit that performs the
PCM encoding and decoding functions
a. Codec
b. Modem
c. Muldem
d. Digital-to-analog converter
135. A synchronous transmission
begins with which character?
a. SYN
b. STX
c. SOH
d. ETB
usually
136. A theory that establishes the minimum
sampling rate that can be used for a given
PCM systems
a. Nyquist sampling theorem
b. Nyquist minimum bandwidth
c. Nyquist minimum bandwidth
d. Any of these
137. Sixteen different levels (symbols) are used
to encode binary data. The channel
bandwidth is 36 MHz. The maximum
channel capacity is
a. 18 Mbps
b. 72 Mbps
c. 288 Mbps
d. 2.176 Gbps
138. Assigning PCM
magnitudes
a. Coding
b. Quantizing
c. Sampling
d. Any of these
codes
to
142. What is the minimum bandwidth required
to transmit a 56 kbps binary signal with no
noise?
a. 14 kHz
b. 56 kHz
c. 28 kHz
d. 112 kHz
143. Type of PCM that uses single-bit PCM
code to achieve digital transmission of
analog signals
a. Adaptive delta modulation
b. Pulse code modulation
c. Differential modulation
d. Delta modulation
144. It is a delta modulation system where the
step size of the digital-to-analog converter
is automatically varied, depending on the
analog input signal.
a. Adaptive Delta Modulation
b. PCM
c. Differential modulation
d. Delta modulation
absolute
139. A popular PC protocol is
a. Parity
b. Xmodem
c. CRC
d. LRC
140. It is the ratio of the largest possible
magnitude to the smallest possible
magnitude that can be decoded by the
digital-to-analog converter in the receiver
a. Coding efficiency
b. Companding
c. Pre-emphasis
d. Dynamic range
141. Devices used for digitizing speech signals
only
a. codec
b. muldem
c. vocoders
d. modem
145. A QAM modulator does not use ____.
a. XNOR
b. Bit Splitter
c. Balanced modulator
d. 2-to-4 level converter
146. It is a form of phase-division multiplexing
where two data channels modulate the
same carrier frequency that is shifted 90
degrees in phase.
a. PSK
b. FSK
c. QAM
d. ASK
147. One eight-bit PCM code is called ______.
a. FDM frame
b. TDM time slot
c. TDM frame
d. FDM time slot
148. It is communications system that uses
digital pulse rather than analog signals to
encode information
a. Digital carrier system
b. Digital baseband system
c. Digital service system
d. Digital broadband system
149. A special device that upgrades signals
from one level to a higher level of the
hierarchy in multiplexing
a. Muldem
b. Vocoder
c. Modem
d. Codec
150. A transmission of binary data which
involves the transmission of only a single
non-zero voltage level.
a. Unipolar
b. Bipolar
c. Polar
d. Non-return to zero
MULTIPLE CHOICE
QUESTIONS
IN
ELECTRONICS SYSTEMS AND
TECHNOLOGIES (EST)
Antennas
MELVIN C. ARCEO, ECE
PERC DC
ENCODED BY:
BADILLO, AIMIE E.
2006105942
ECE003/C11
1. It is a metallic conductor system capable of
radiating and capturing electromagnetic
energy
a. transmission lines
b. antenna
c. waveguides
d. load
8. Electrical energy that has escaped into free
space in the form of transverse
electromagnetic waves
a. Radio waves
b. Frequency
c. Signal
d. Wavelength
2. A directional antenna with two or more
elements is known as
a. folded dipole
b. ground plane
c. loop
d. array
9. The length of the ground plane vertical at
146 MHz is
a. 1.6 ft
b. 1.68 ft
c. 2.05 ft
d. 3.37 ft
3. The ratio of the focal length to the diameter
of the mouth of the parabola is called _____.
a. aperture
b. focal point
c. foci
d. major axis
10. Using a small reflector to beam waves to the
larger parabolic reflector is known as
a. Focal feed
b. Horn feed
c. Cassegrain feed
d. Coax feed
4. The impedance of a dipole is about
a. 50-ohm
b. 73-ohm
c. 93-ohm
d. 300-ohm
11. The plane parallel to the mutually
perpendicular line in the electric and
magnetic fields is called _______.
a. wavefront
b. point source
c. isotropic source
d. rays
5. A special type of transmission line that
consist of conducting metallic tube through
which high frequency electromagnetic
energy is propagated
a. medium
b. microstrip
c. stripline
d. waveguide
12. What is the beamwidth of a parabolic
antenna with a diameter of 5 meters and an
operating frequency of 10 GHz?
a. 0.5 degrees
b. 0.675 degrees
c. 0.348 degrees
d. 3.48 degrees
6. Calculate the angle of declination for an
antenna using a polar mount at a latitude of
45 degrees
a. 3.2 degrees
b. 1.3 degrees
c. 4.2 degrees
d. 6.81 degrees
13. The horizontal radiation pattern of a dipole
is a
a. circle
b. figure of eight
c. clover leaf
d. narrow beam
7. The cone angle of the flare angle of a
conical horn antenna is approximately
a. 55 degrees
b. 45 degrees
c. 40 degrees
d. 50 degrees
14. The size of antenna is inversely proportional
to _______.
a. frequency
b. power
c. radiation resistance
d. wavelength
15. A popular half – wave antenna is the
a. Ground plane
b. End-fire
c. Collinear
d. Dipole
16. Calculate the gain of a parabolic antenna
using a 2.5-m radius dish operating at
10GHz.
a. 166.673 dB
b. 83.7 dB
c. 52.2 dB
d. 45.6 dB
17. It is the ratio of the radiated to the reflected
energy
a. Radiation resistance
b. Radiation efficiency
c. Radiation constant
d. Radiation antenna
18. The feed mechanism in a parabolic antenna
that radiates the electromagnetic energy.
a. Primary antenna
b. Reflectors
c. Secondary antenna
d. Focal point
19. It is a polar diagram or graph representing
field strengths or power densities at various
angular positions relative to an antenna
a. Side lobe
b. Front lobe
c. Radiation pattern
d. Radiation constant
20. For a transmit antenna with a radiation
resistance of 72 ohms, an effective antenna
resistance of 8 ohms, a directive gain of 20
and an input power of 100W, determine the
antenna gain.
a. 12.55 dB
b. 10.43 dB
c. 11.21 dB
d. 9.78 dB
21. The radiation pattern plotted in terms of
electric field strength or power density
a. absolute radiation pattern
b. relative radiation pattern
c. absolute front lobe pattern
d. absolute side lobe pattern
22. Calculate the characteristic impedance of a
quarter – wavelength section used to connect
a 300-ohm antenna to a 75-ohm line
a. 150 ohms
b. 120 ohms
c. 130 ohms
d. 110 ohms
23. Plots of field strength or power density with
respect to the value at a reference point
a. absolute front lobe pattern
b. relative front lobe pattern
c. relative front lobe pattern
d. relative radiation pattern
24. What must be the height of a vertical
radiator one half wavelength high if the
operating frequency is 1100 kHz?
a. 120 m
b. 136 m
c. 115 m
d. 124 m
25. Lobes adjacent to the front lobe
a. Diagonal lobes
b. Side lobes
c. Front lobes
d. Back lobes
26. Lobes in a direction exactly opposite of the
front lobe
a. Side lobes
b. Adjacent lobes
c. Front lobes
d. Back lobes
27. Calculate the efficiency of an antenna that
has a radiation resistance of 73 ohms and an
effective dissipation resistance of 5 ohms
a. 98.3%
b. 93.6%
c. 90.7%
d. 95.5%
28. The line bisecting the major lobe, or
pointing from the center of the antenna in
the direction of maximum radiation is called
_______.
a. line of shoot
b. diagonal shoot
c. bisecting shoot
d. antenna shoot
29. The ammeter connected at the base of a
Marconi antenna has a certain reading. If
this reading is increased 2.77 times, what is
the increase in output power?
a. 3.45
b. 1.89
c. 2.35
d. 7.67
30. Refers to a field pattern that is close to the
antenna.
a. Induction field
b. Far field
c. Radiation field
d. Capture field
31. A half-wave dipole is driven with a 5-W
signal at 225 MHz. A receiving dipole 100
km. Calculate the received power into a 73ohm receiver.
a. 23.5 pW
b. 7.57 pW
c. 5.64 pW
d. 1.26 pW
32. It is the resistance that, if it replaced the
antenna, would dissipate exactly the same
amount of power that the antenna radiates.
a. Directive gain
b. Antenna efficiency
c. Radiation resistance
d. Antenna resistance
33. What is the effective radiated power of a
television broadcast station if the output of
the transmitter is 1000W, antenna
transmission line loss is 50W, and the
antenna power gain is 3?
a. 1250 W
b. 2370 W
c. 2130 W
d. 2850 W
34. It is the ratio of the power radiated by an
antenna to the sum of the power radiated and
the power dissipated.
a. radiation resistance
b. coupling coefficient
c. antenna efficiency
d. antenna beamwidth
35. It is the ratio of the power radiated by the
antenna to the total input power.
a. antenna efficiency
b. reflection coefficient
c. standing wave ratio
d. radiation resistance
36. If a 500 kHz transmitter of a constant power
produces field strength of 100uV/m at a
distance of 100 mi from the transmitter,
what would be the theoretical field strength
at a distance of 200 mi from the transmitter?
a. 45 uV/m
b. 100 uV/m
c. 50 uV/m
d. 35 uV/m
37. An antenna that transmits or receives
equally well in all directions is said to be
_____.
a. omnidirectional
b. bidirectional
c. unidirectional
d. quasidirectional
38. It is the ratio of the power density radiated
in a particular direction to the power density
radiated to the same point by a reference
antenna, assuming both antennas are
radiating the same amount of power
a. power gain
b. directive gain
c. total gain
d. system gain
39. If the field intensity of 25 mV/m develops
2.7 V in a certain antenna, what is its
effective height?
a. 110 m
b. 100 m
c. 98 m
d. 108 m
40. The magnetic field of an antenna is
perpendicular to the earth. The antenna’s
polarization ______.
a. is vertical
b. is horizontal
c. is circular
d. cannot be determined from the
information given
41. If the power of a 500 kHz transmitter is
increased from 150 W to 300 W, what
would be the percentage change in field
intensity at a given distance from the
transmitter?
a. 141%
b. 150%
c. 100%
d. 133%
42. It is the same with directive gain except that
the total power fed to the antenna is used
and the antenna efficiency is taken into
account.
a. system gain
b. power gain
c. directive gain
d. total gain
43. A hip-radio telephone transmitter operates
on 2738 kHz. At a certain point distant from
the transmitter, the 2738 kHz signal is
measured field of 147 mV/m. The second
harmonic field at the same point is measured
as 405 uV/m. To the nearest whole unit in
decibels, how much has the harmonic
emission been attenuated below the 2738
kHz fundamental?
a. 43.2 dB
b. 51.2 dB
c. 35.1 dB
d. 25.1 dB
44. It is the equivalent power that an isotropic
antenna would have to radiate to achieve the
same power density in the chosen direction
at a given point as another antenna.
a. EIRP
b. ERP
c. IRL
d. RSL
45. When the energy is applied to the antenna at
a point of high – circulating current.
a. voltage-fed antenna
b. power-fed antenna
c. current-fed antenna
d. impedance-fed antenna
46. For a transmit antenna with a power gain of
10 and an input power of 100W, determine
the EIRP in watts.
a.
b.
c.
d.
30 dBW
40 dBW
50 dBW
20 dBW
47. If energy is applied at the geometrical center
of antenna, the antenna is said to be _____.
a. center-fed
b. end-fed
c. quarterwave-fed
d. halfwave-fed
48. For a transmit antenna with a power gain of
10 and an input power of 100W, determine
the power density at a point 10 km from the
transmit antenna
a. 0.574 uW/m^2
b. 0.796 uW/m^2
c. 1.24 uW/m^2
d. 0.981 uW/m^2
49. For a transmit antenna with a radiation
resistance of 72 ohms, an effective antenna
resistance of 8 ohms, a directive gain of 20
and an input power of 100W, determine the
antenna efficiency.
a. 90%
b. 96%
c. 98%
d. 96%
50. The fields surrounding the antenna do not
collapse their energy back into the antenna
but rather radiate it out in space.
a. induction field
b. near field
c. radiation field
d. magnetic field
51. For receive power density of 10 uW/m^2
and a receive antenna with a capture area of
0.2 m^2, determine the captured power.
a. 0.5 uW
b. 2 uW
c. 1 uW
d. 1.5 uW
52. The property of interchangeability for the
transmitting and receiving operations is
known as ______.
a. efficiency
b. accuracy
c. reciprocity
d. polarization
53. The length of a doublet at 27 MHz is _____.
a. 8.67 ft
b. 17.3 ft
c. 18.2 ft
d. 34.67 ft
54. Refers to the orientation of the electric field
radiated from an antenna.
a. efficiency
b. beamwidth
c. polarization
d. accuracy
55. At frequencies below 2 MHz, what type of
antenna is usually used?
a. Marconi antenna
b. Hertzian antenna
c. Hertz antenna
d. Elementary doublet
56. The angular separation between two halfpower points in the major lobe of the
antenna’s plane radiation pattern.
a. bandwidth
b. polarization
c. efficiency
d. beamwidth
57. Hertz antenna are predominantly used with
frequencies above
a. 3 MHz
b. 4 MHz
c. 5MHz
d. 2MHz
58. Defined as the frequency range over which
antenna operation is satisfactory
a. beamwidth
b. channel
c. bandwidth
d. baseband
59. One of the following
omnidirectional antenna.
a. Half-wave dipole
b. Log-periodic
c. Discone
d. Marconi
is
not
an
60. The point on the antenna where the
transmission line is connected is called
_______.
a. center feed
b. end feed
c. feedpoint
d. voltage feed
61. A popular vertical antenna is the _____>
a. collinear
b. dipole
c. ground plane
d. broadside
62. The discone antenna is
a. a useful direction-finding antenna
b. used as a radar receiving antenna
c. circularly polarized with other
circular antennas
d. useful as a UHF receiving antenna
63. The feedpoint presents and ac load to the
transmission line called
a. antenna output impedance
b. antenna input impedance
c. feedpoint impedance
d. center feed impedance
64. A helical antenna is used for satellite
tracking because of its
a. circular polarization
b. maneuverability
c. broad bandwidth
d. good front to back ratio
65. The simplest type of antenna.
a. Elementary doublet
b. Half-wave dipole
c. Quarterwave dipole
d. 5/8 wavelength dipole
66. Zoning is used with a dielectric antenna in
order to
a. reduce the bulk of the lens
b. increase the bandwidth of the lens
c. permit pin-point focusing
d. correct the curvature of the
wavefront from a horn that is too
short
67. It is an electrically short dipole
a. short dipole
b. quarterwave dipole
c. half-wave dipole
d. yagi antenna
74. An antenna that is circularly polarized is the
a. helical
b. small circular loop
c. parabolic reflector
d. Yagi – Uda
68. Cassegrain feed is used with parabolic
reflector to
a. increase the gain of the system
b. increase the bandwidth of the system
c. reduce the size of the main reflector
d. allow the feed to be placed at a
convenient point
75. It is a wire structure placed below the
antenna and erected above the ground.
a. ground plane
b. counterpoise
c. ground lines
d. top hat
69. The half-wave dipole is generally referred to
as ______.
a. Yagi antenna
b. Hertzian antenna
c. Marconi antenna
d. Hertz antenna
70. Top loading is sometimes used with an
antenna in order to increase its
a. effective height
b. bandwidth
c. beamwidth
d. input capacitance
71. What is the directivity of a Hertz antenna?
a. 1.64
b. 2.18
c. 2.15
d. 1.75
72. The standard reference antenna for the
directive gain is the _______.
a. infinitesimal dipole
b. isotropic antenna
c. elementary doublet
d. half-wave dipole
73. An antenna which is one-quarter wavelength
long, mounted vertically with the lower end
either connected directly to ground or
grounded through the antenna coupling
network.
a. loop antenna
b. hertzian dipole
c. monopole antenna
d. turnstile antenna
76. Which of the following terms does not apply
to the Yagi-Uda array?
a. good bandwidth
b. parasitic elements
c. folded dipole
d. high gain
77. It effectively cancels out the capacitance
component of the antenna input impedance.
a. ground plane
b. top hat
c. loading coil
d. shunt capacitance
78. Indicate which of the following reasons for
the use of an earth mat with antenna is false:
a. impossibility of a good ground
conduction
b. provision of an earth for an antenna
c. protection of personnel working
underneath
d. improvement of the radiation pattern
of the antenna
79. A metallic array that resembles a spoke
wheel placed at the top of an antenna, it
increases the shunt capacitance to ground
reducing the overall antenna capacitance.
a. loading coil
b. top loading
c. series capacitance
d. series inductors
80. Indicate the antenna that is not wideband:
a. discone
b. folded dipole
c. helical
d. marconi
81. It is formed when two or more antenna
elements are combined to form a single
antenna.
a. antenna elements
b. antenna array
c. driven elements
d. parasitic elements
82. One of the following is not a reason for the
use of an antenna coupler:
a. to make the antenna look resistive
b. to provide the output amplifier with
the correct load impedance
c. to discriminate against harmonics
d. to prevent reradiation of local
oscillators
83. It is an individual radiator, such as a half or
quarter-wave dipole.
a. antenna element
b. antenna array
c. reflector
d. director
84. Indicate which of the following reasons for
using a counterpoise with antennas is false:
a. impossibility of a good ground
connection
b. protection of personnel working
underneath
c. provision of an earth for the antenna
d. rockiness of the ground itself
85. Type of antenna element that is directly
connected to the transmission lines and
receives from or is driven by the source.
a. driven array
b. parasitic array
c. driven element
d. parasitic element
c. parasitic array
d. parasitic element
88. One of the following is very useful as a
multi-band HF receiving antenna. This is
the:
a. conical horn
b. folded dipole
c. log-periodic
d. square loop
89. A parasitic element that is longer than the
driven element from which it receives
energy.
a. driven element
b. director
c. parasitic elements
d. reflector
90. One of the following consists of nonresonant antennas.
a. rhombic antenna
b. folded-dipole antenna
c. end-fire antenna
d. broadside antenna
91. A parasitic element that is shorter than its
associated driven element.
a. redirector
b. director
c. reflector
d. parasitic element
92. An ungrounded antenna near the ground.
a. acts as a single antenna near the
ground
b. is unlikely to need an earth mat
c. acts as an antenna array
d. must be horizontally polarized
86. Which of the following antennas is best
excited from a waveguide?
a. biconical
b. horn
c. helical
d. discone
93. It is a non-resonant antenna capable of
operating satisfactorily over a relatively
wide bandwidth, making it ideally suited for
HF transmission.
a. turnstile antenna
b. loop antenna
c. rhombic antenna
d. discone antenna
87. Type of antenna element that is not
connected to the transmission lines.
a. parasitic array
b. driven array
94. A wide – bandwidth multi-element driven
array is the ______.
a. end-fire
b. log-periodic
c. yagi
d. collinear
95. It is a linear array antenna consisting of a
dipole and two or more parasitic elements:
one reflector and one director.
a. broadside antenna
b. end-fire antenna
c. yagi-uda antenna
d. phased array antenna
96. An antenna which is consists of a cone that
is truncated in a piece of circular waveguide.
a. pyramidal horn antenna
b. circular horn antenna
c. rectangular horn antenna
d. circular horn antenna
97. Which antenna has a unidirectional radiation
pattern and gain?
a. dipole
b. ground plane
c. yagi
d. collinear
98. An antenna formed by placing two dipoles
at right angles to each other, 90 degrees out
of phase.
a. discone antenna
b. turnstile antenna
c. bicone antenna
d. 5/8 wavelength antenna
99. The radiation pattern of collinear and a
broadside antenna is ________.
a. omnidirectional
b. bidirectional
c. unidirectional
d. clover-leaf shaped
100. What is the bandwidth ration of logperiodic antenna?
a. 10:1
b. 5:1
c. 20:1
d. 1:10
101. Which beam width represents the best
antenna directivity?
a. 7 degrees
b. 12 degrees
c. 19 degrees
d. 28 degrees
102. It is the ratio of the highest to the lowest
frequency over which an antenna will
satisfactorily operate.
a. channel ratio
b. bandwidth ratio
c. reflection ratio
d. dynamic range
103. An antenna has a power gain off 15. The
power applied to the antenna is 32 W. The
effective radiated power is ________.
a. 15 W
b. 32 W
c. 120 W
d. 480 W
104. It is simply a single-turn coil of wire that
is significantly shorter than one
wavelength and carries RF current.
a. turnstile antenna
b. loop antenna
c. rhombic antenna
d. long-wire antenna
105. A coax has an attenuation of 2.4 dB per
100 ft. The attenuation of 275 ft
a. 2.4 dB
b. 3.3 dB
c. 4.8 dB
d. 6.6 dB
106. It is group of antenna arrays that when
connected together, function as a simple
antenna whose beamwidth and direction
can be changed electronically without
having to physically move any of the
individual antennas or antenna elements
within the array.
a. end-fire array
b. broadside antenna
c. phased array antenna
d. log-periodic antenna
107. Conductors in multi-element antennas that
do not receive energy directly from the
transmission line are known as ______.
a. parasitic element
b. driven element
c. the boom
d. receptor
108. It is a broadband VHF or UHF antenna
that is suited for applications for which
radiating circular rather than horizontal or
vertical polarized electromagnetic waves
are required.
a. discone antenna
b. bicone antenna
c. log-periodic antenna
d. helical antenna
109. Mode of propagation of helical antenna
where electromagnetic radiation is in the
direction at right angles to the axis of the
helix.
a. normal mode
b. axial mode
c. helix mode
d. helical mode
110. Mode of propagation of helical antenna
where the radiation of the antenna in the
axial direction and produces a broadband
relatively directional pattern.
a. helical mode
b. normal mode
c. axial mode
d. helix mode
111. In a Yagi antenna, maximum direction of
radiation is toward the
a. director
b. driven element
c. reflector
d. sky
112. It is defined as the ratio of the antennas
maximum gain in the forward direction to
its maximum gain in its backward
direction
a. side-to-back ratio
b. front-to-side ratio
c. back-to-side ratio
d. front-to-back ratio
113. The horizontal radiation pattern of a
vertical dipole is a ____________.
a. figure of eight
b. circle
c. narrow beam
d. clover leaf
114. An antenna that provides extremely high
gain and directivity and very popular for
microwave
radio
and
satellite
communications link.
a. helical antenna
b. parabolic antenna
c. hyperbolic antenna
d. log-periodic antenna
115. Part of a parabolic antenna that houses the
primary
antenna
which
radiates
electromagnetic waves toward the
reflector.
a. feed mechanism
b. focal point
c. center feed
d. feed antenna
116. It is a passive device that simply reflects
the energy radiated by the feed mechanism
into a concentrated, highly directional
emission in which the individual waves
are all in phase with each other.
a. director
b. parabolic segment
c. reflector
d. feed mechanism
117. The energy near the edge of the parabolic
dish that does not reflect but rather is
diffracted around the edge of the dish.
a. spillover
b. corona
c. dissipated power
d. copper loss
118. Determines the angular aperture of the
reflector, which indirectly determines how
much the primary radiation is reflected by
the parabolic dish.
a. numerical aperture
b. V number
c. aperture number
d. aperture angle
119. For a 2-m diameter parabolic reflector
with 10W of power radiated by the feed
mechanism operating at 6 GHz with a
transmit antenna efficiency of 55% and an
aperture efficiency of 55%, determine the
beamwidth.
a. 1.25 degrees
b. 2.25 degrees
c. 1.5 degrees
d. 1.75 degrees
120. Type of feed mechanism where the
primary radiating source is located just
behind a small opening at the vertex of the
paraboloid rather than at the focus.
a. cassegrain feed
b. center feed
c. horn feed
d. antenna feed
121. Discone radiation pattern is
a. omnidirectional
b. unidirectional
c. figure-of-eight
d. bidirectional
122. Which is properly terminated antenna?
a. dipole
b. marconi
c. hertz
d. rhombic
123. An example of a marconi antenna is
_______.
a. quarter wave vertical tower
b. collinear
c. yagi
d. rhombic
124. At the ends of a half-wave antenna, what
values of current and voltage exist
compared to the remainder of the antenna?
a. minimum voltage and maximum
current
b. minimum voltage and minimum
current
c. equal voltage and current
d. maximum voltage and minimum
current
125. Radiation resistance is the ratio of ______.
a. radiated power to the antenna center
current
b. radiated power to the square of the
antenna center current
c. voltage to any point of the antenna
d. square of voltage to the square of
current at any point in the antenna
126. Consists of basic antenna connected to a
transmission line plus one or more
additional conductors
a. parasitic array
b. directors
c. driven array
d. reflectors
127. Which of the following is not a driven
array?
a. yagi
b. broadside
c. collinear
d. end fire
128. What is used to determine phase
difference
between two
broadcast
antennas?
a. a phase monitor
b. a frequency monitor
c. an amplitude monitor
d. a power monitor
129. In antennas, which gives more forward
gain?
a. reflector
b. driven element
c. parasitic element
d. director
130. Which of the following is longer?
a. director
b. reflector
c. driven element
d. parasitic element
131. Which is closer to the driven element?
a. parasitic element
b. driven element
c. director
d. reflector
132. How much do they differ in length from a
half-wavelength?
a. 5%
b. 10%
c. 15%
d. 20%
133. How much more feed-point impedance
does a folded dipole have than a normal
dipole?
a.
b.
c.
d.
two times as much
three times as much
four times as much
five times as much
134. How is it possible to produce 70-ohm twin
lead?
a. by folding more parasitic element
b. by manufacturing
c. by increasing the radiation resistance
d. by increasing the length of the
antenna
135. With similar size parabolic, plane
reflector, and corner-reflector beams,
which has greater gain?
a. plane reflector
b. parabolic
c. corner-reflector beam
d. V-beam
136. With similar size, which has the narrowest
lobes?
a. parabolic
b. V-beam
c. corner-reflector beam
d. plane reflector
137. Why would the wires of V-beam be closer
together when used on higher frequencies?
a. main lobe lays farther to wire
b. main lobe lays closer to wire
c. secondary lobes closer to wire
d. secondary lobes farther to wire
138. How the V-beam is made unidirectional?
a. impedance terminated
b. capacitive terminated
c. inductive terminated
d. resistor terminated
139. Why might a rhombic be better than a Vbeam?
a. it is resistor terminated
b. more acreage needed
c. less acreage needed
d. it is unidirectional
140. Why is the usual rhombic not frequency –
sensitive?
a. unidirectional
b. with its characteristic impedance
c. less acreage required
d. main lobe is greater than back lobe
141. In what direction is the null of small
diameter loop in relation to the plane of
the loop?
a. 45 degrees angle
b. 180 degrees angle
c. 360 degrees angle
d. 90 degrees angle
142. When is a loop unidirectional?
a. when horizontal
b. when vertical
c. when circular
d. when unidirectional
143. Why are verticals sometimes top-loaded?
a. to resonate on high frequency
b. to decrease the electrical length
c. to resonate on low frequency
d. to look better
144. Why is pi-network superior to direct
coupling to an antenna?
a. reduce harmonic radiation
b. better frequency response
c. better radiation of energy
d. reduce power dissipation
145. Why might L networks be used between
an antenna and transmission line?
a. step impedance up
b. step impedance down
c. better radiation of energy
d. reduce power radiation
146. Why are antenna ammeters often shorted
out or disconnected from the antenna
except when readings are desired?
a. to replace it with dummy
b. not to interface with transmission
c. for proper reception of signals
d. to protect from lightning
147. Device to split transmission line current to
two or more antenna towers
a. splitter
b. coupler
c. isolator
d. phasor circuit
148. What method can be used to determine the
feed-point impedance of a vertical
antenna?
a. resistance substitution
b. impedance matching
c. dissipated resistance measurement
d. grounding the antenna
149. In what unit is field intensity measured?
a. volts
b. amperes
c. watts/m
d. mV/m
150. How fast does low-frequency field
strength attenuate?
a. directly proportional to distance
b. inversely proportional to distance
c. directly proportional to time
d. inversely proportional to time
MULTIPLE CHOICE
QUESTIONS
IN
ELECTRONICS SYSTEMS AND
TECHNOLOGIES (EST)
Broadcast Engineering
MELVIN C. ARCEO, ECE
PERC DC
ENCODED BY:
BADILLO, AIMIE E.
2006105942
ECE003/C11
1. In stereophonic broadcast, the center
frequency of each SCA Subcarrier shall be
kept at all times within _______ Hz of the
authorized frequency.
a. 200
b. 300
c. 400
d. 500
2. Sawtooth generator circuits produce the
scanning raster but the sync pulses are
needed for
a. linearity
b. timing
c. keystoning
d. line pairing
3. Which of the following camera tubes has
minimum lag?
a. Vidicon
b. Plumbicon
c. Saticon
d. Iconoscope
4. The service are in standard AM broadcast is
described as ______ if there is no fading of
signal.
a. Class A
b. Secondary
c. Class B
d. Primary
5. The vertical field-scanning frequency is
______ Hz.
a. 30
b. 60
c. 525
d. 15,750
6. A 4.5-MHz signal which is equal to the
difference between the picture and sound RF
carrier frequencies in a 6-MHz TV channel.
a. Audio frequency
b. Video frequency
c. Intercarrier frequency
d. Subcarrier frequency
7. A system where the modulated RF picture
and sound carrier signals are distributed in a
cable network, instead of wireless system.
a. CCTV
b. MATV
c. CATV
d. SATV
8. A class A FM station is limited in antenna
height of ______ feet above average terrain.
a. 1000
b. 2000
c. 4000
d. 5000
9. What circuit in the TV receiver is used to
develop the high voltage needed to operate
the picture tube?
a. Low-voltage power supply
b. Horizontal output
c. Vertical sweep
d. Sync separator
10. The modulated picture carrier wave includes
the composite video signal as the
a. Average carrier level
b. Symmetric envelope of amplitude
variations
c. Lower sideband without the upper
sideband
d. Upper envelope without the lower
envelope
11. With which emission type is the captureeffect more pronounced?
a. CW
b. FM
c. SSB
d. AM
12. The hue of color sync phase is
a. red
b. cyan
c. blue
d. yellow green
13. How much is the equivalent internal
resistance of the electron beam with a 1.2mA beam current at 25 kV?
a. 48 nano ohms
b. 30 ohms
c. 20.8 mega ohms
d. 15.6 kilo ohms
14. The difference between the picture and
sound carrier frequencies for channel 3 is
______ MHz.
a.
b.
c.
d.
3.58
64.5
4.5
6.75
15. Refers to the deviation of the operating
frequency of a crystal oscillator from its
nominal value due to temperature variations.
a. drift
b. flashover
c. frequency deviation
d. deviation ratio
16. It is the measure of how many picture
elements can be reproduced
a. definition
b. resolution
c. detail
d. any of these
17. A 3.58-MHz subcarrier signal for color in
television
a. Hue signal
b. Video signal
c. Audio signal
d. Chroma signal
18. A class D FM station shall have an
authorized power not exceeding ______
watts.
a. 20
b. 15
c. 10
d. 5
19. Which of the following is not a benefit of
cable TV?
a. Lower-cost reception
b. Greater stability
c. Less noise, stronger signal
d. Premium cable channels
20. The width of the vertical sync pulse in the
Philippine TV system is
a. 21H
b. 3H
c. H
d. 0.5H
21. Term in communication which is referred,
“to send out in all direction”
a. announce
b. broadcast
c. transmit
d. media
22. The number of frames per second in the
Philippine TV system is
a. 60
b. 262 ½
c. 4.5
d. 30
23. It means multiple outlines of edges to the
right in the picture.
a. ghosting
b. ringing
c. fading
d. snowing
24. In the Sawtooth waveform for linear
scanning,
a. the linear rise is for flyback
b. the complete cycle includes trace
and retrace
c. the sharp reversal in amplitude
produces trace
d. the beam moves faster during trace
and retrace
25. The purpose of pre-emphasis and deemphasis in FM broadcasting is to:
a. increase
the
high
frequency
amplitude
b. improve the audio harmonic
c. decrease
the
low
frequency
amplitude
d. improve the S/N ratio
26. The part of the visible spectrum where
camera pickup tubes have the greatest output
is
a. red
b. blue
c. yellow-green
d. infrared
27. The type of modulation of the sound carrier
signal is ______.
a. Pulse motion
b. Phase modulation
c. Amplitude modulation
d. Frequency modulation
28. A video or audio signal that can be used
directly to reproduce the picture and sound.
a. Baseband signal
b. Broadband signal
c. Electromagnetic wave signal
d. Modulated signal
29. Class B FM station should have an ERP not
exceeding ______ kW.
a. 50
b. 40
c. 30
d. 20
30. What technique is used to permit hundreds
of TV signals to share a common cable?
a. Frequency modulation
b. Mixing
c. Frequency division multiplexing
d. Time division multiplexing
31. Another name for the horizontal retrace in a
TV receiver is the
a. ringing
b. burst
c. damper
d. flyback
32. In the Philippine color television system, the
intercarrier frequency, in MHz, is
a. 3.58
b. 3.579645
c. 4.5
d. 45.75
33. In channel 14 (470 to 476 MHz), the 3.58MHz color signal is transmitted at
a. 471.25 MHz
b. 473.25 MHz
c. 474.83 MHz
d. 475.25 MHz
34. Interlaced scanning eliminates
a. snowing
b. flicker
c. distortion
d. fading
35. Beam alignment magnets for the camera
tube are adjusted while rocking which color?
a. Optical focus
b. Electrical focus
c. Beam current
d. Shading
36. What is a frequency discriminator?
a. An FM generator
b. A circuit for detecting FM
c. A circuit for filtering two closely
adjacent signals
d. An automatic bandwidth circuit
37. A system used in television field operation
to make on-the-spot video tape recordings
using portable TV cameras and VTRs.
a. SNG
b. ENG
c. HAFC
d. MATV
38. Class B FM station shall have an authorized
transmitter power not exceeding ______
kW.
a. 10
b. 100
c. 1000
d. 10000
39. The total bandwidth of an NTSC TV signal
is
a. 3.58 MHz
b. 4.5 MHz
c. 6 MHz
d. 10.7 MHz
40. Referred to the oscillator signal “leak
through” from a property neutralized
amplifier such as a master oscillator power
amplifier.
a. carrier
b. stray signal
c. back wave
d. loss wave
41. Interlacing is used in television to
a. produce the illusion of motion
b. ensure that all lines on the screen are
scanned, not merely the alternate
ones
c. simply the vertical sync pulse train
d. avoid flicker
42. Coaxial cable for distribution system has an
impedance of
a.
b.
c.
d.
50 ohms
75 ohms
150 ohms
300 ohms
43. The average voltage value of the 3.58-MHz
modulated chrominance signal is
a. zero for most colors
b. close to black for yellow
c. the brightness of the color
d. the saturation of the color
44. When does broadcast station conduct an
equipment test?
a. during day time
b. during night time
c. during experimental period
d. at any time
45. It causes the picture information to spread
out or crowded at one end of the rater
compared to the opposite end.
a. Linear scanning
b. Interlaced scanning
c. Non-linear scanning
d. Retrace
46. If the camera cannot be placed far away
enough to include everything in the scene,
change the lens to one with a
a. lower f rating
b. higher f rating
c. longer focal length
d. shorter focal length
high powered RF transmission and are
limited to radio frequency of about 500 kHz.
a. Arc transmitter
b. Hartley transmitter
c. Spark transmitter
d. Frequency transmitter
50. A technique where segments of videotape
are joined by electronic erasing and
recording to create a single program.
a. masking
b. segmenting
c. editing
d. programming
51. A class C FM station has an authorized
power not exceeding ______watts of ERP.
a. 500
b. 750
c. 1000
d. 2000
52. The assembly around the neck of a picture
tube that produces the magnetic fields that
deflect and scan the electron beams is called
the _________.
a. shadow mask
b. phosphor
c. electron gun
d. yoke
47. Type of radio communication transmission
utilizing frequency modulation technique
a. television video
b. broadcasting in 535-1606 kHz
c. single sideband HF transmission
d. television audio
53. An odd number of lines per frame form part
of every one of the world’s TV systems.
This is _____________________.
a. done to assist interface
b. purely an accident
c. to ensure that line and frame
frequencies can be obtained from the
same original source
d. done to minimize interference with
the chroma subcarrier
48. The amount of color in the picture or color
intensity in the ______.
a. color level
b. chroma level
c. saturation
d. any of these
54. The difference between the sound carrier
and the color signal is
a. 4.5 MHz
b. 1.25 MHz
c. 0.92 MHz
d. 0.25 MHz
49. One of the early radio transmitters which
produced keyed carrier generating purer
waveform than spark transmitter, used for
55. In color television, it is made for uniform
color in the raster.
a. beam-landing adjustment
b. degaussing
c. internal blanking adjustment
d. background control
56. Which of the following camera tubes uses
lead oxide for the photoconductive target
plate?
a. vidicon
b. plumbicon
c. saticon
d. image orthicon
57. The number of fields is ______ per frame.
a. 2
b. 60
c. 525
d. 262.5
58. An RF carrier wave that is frequency –
modulated by the baseband audio signal in
TV broadcasting.
a. Audio signal
b. Video signal
c. Intercarrier signal
d. Color signal
59. A class B FM station is limited in antenna
height of ____ feet.
a. 1000
b. 500
c. 250
d. 100
60. The HV anode supply for the picture tube of
a TV receiver is generated in the
a. mains transformer
b. vertical output stage
c. horizontal output stage
d. horizontal deflection oscillator
61. A tap for the subscriber drop line has a
a. high insertion loss
b. high tap loss
c. low tap loss
d. 300-ohm impedance
62. Which system can be used for both
recording and playback?
a. CED
b. VHD
c. laser disk
d. VHS
63. The hue 180 degrees out of phase with red is
______.
a. cyan
b. yellow
c. green
d. blue
64. It is used around the phosphor dots to make
a darker black which improves contrast in
the picture.
a. black masking
b. convergence adjustment
c. shadow masking
d. color parity adjustment
65. A lens with lower f rating is _____ lens that
allows more light input.
a. slower
b. wider
c. narrower
d. faster
66. Picture frames are repeated at the rate of ___
per second.
a. 30
b. 60
c. 45
d. 50
67. The effective radiated power of a class A
FM station should not exceed ______ kW.
a. 125
b. 30
c. 10
d. 1
68. In television, 4:3 represents the
a. interface ratio
b. maximum horizontal deflection
c. aspect ratio
d. ration of the two diagonals
69. Titling the viseo head gaps is necessary with
the
a. color under
b. zero guard bands
c. FM luminance signal
d. Long – play tapes
70. It is a special camera tube with a test pattern
printed in the image plate.
a. vidicon
b. monoscope
c. oscilloscope
d. iconoscope
71. The number of lines scanned per frame in
the raster on the picture tube screen is
a. 525
b. 262 ½
c. 20
d. 10
72. 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 of 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. MOPA
b. Hartley
c. Alexanderson
d. Goldsmith
73. Camera signal output without sync is called
______.
a. black burst
b. generator lock video
c. composite video
d. non-composite video
74. The tint of the color is its _____.
a. brightness
b. contrast
c. chroma
d. hue
75. Which frequency band is the standard AM
radio broadcast?
a. HF
b. UHF
c. MF
d. VHF
76. The I and Q composite color signals are
multiplexed onto the picture carrier by
modulating a 3.58 MHz subcarrier using
a. FM
b. PM
c. DSB AM
d. Vestigial sideband AM
77. The shadow mask in color picture tube is
used to
a. Reduce X-ray emission
b. Ensure that each beam hits only its
dots
c. Increase screen brightness
d. Provide degaussing for the screen
78. The video heads rotate at high velocity to
increase the
a. tape speed
b. writing speed
c. reel rotation
d. tape tension
79. How do you eliminate radio frequency
variation of an oscillator transmitter caused
by its supply voltage?
a. use of a regulated power supply
b. use of a new power supply
c. use of high capacitor in the supply
circuit
d. loosen power supply shielding
80. The composite video signal includes the
camera signal with the following except
a. picture information
b. sync pulses
c. blanking pulses
d. camera signal
81. A lens has an 8-cm focal length and 4-cm
diameter. Its f rating is
a. 2
b. 4
c. 8
d. 32
82. Which of the following is a possible cause
for an abrupt frequency variation in a self –
excited transmitter oscillator circuits
resulting poor frequency stability to hold a
constant frequency oscillation?
a. DC and RF AC heating of resistor
which cause a change in values
b. Heating and expansion of oscillator
coil
c. Heating of capacitor in the oscillator
d. Power supply voltage changes
83. How long does it take to scan 2 picture
elements when 400 are scanned in 50
microseconds?
a. 25 microsec
b. 0.25 microsec
c. 2.5 microsec
d. 0.5 microsec
90. It is the light flux intercepted by a one-footsquare surface that is one-foot from a onecandlepower source.
a. candela
b. footcandle
c. lux
d. lumens
84. Anode voltage for the picture tube,
developed from the output of the horizontal
deflection circuit.
a. Yoke voltage
b. Flyback voltage
c. Aquadag voltage
d. Tube voltage
91. Refers to the possible cause of an abrupt
frequency variations in a self-excited
transmitter oscillator circuit resulting to a
poor frequency stability to hold a constant
oscillator.
a. poor soldered connections
b. heating of capacitor in the oscillator
c. DC and AC heating of resistors
which cause change in values
d. Aging which cause change in
condition in parts characteristics
85. The channel spacing in the Philippine FM
broadcast standards
a. 400 kHz
b. 800 kHz
c. 600 kHz
d. 200 kHz
86. What is the black-and-white or monochrome
brightness signal in TV called?
a. RGB
b. Color subcarrier
c. Q an I
d. Luminance Y
87. Which of the following is a midband cable
TV channel?
a. 6
b. 7
c. 14
d. 23
88. What is the primary purpose of an RF
amplifier in a receiver?
a. to vary the receiver image rejection
by utilizing the AGC
b. to provide most of the receiver gain
c. to develop the AGC voltage
d. to improve the receiver’s noise
figure
89. The color with the most luminance is
a. red
b. yellow
c. green
d. blue
92. It is the difference in intensity between the
black parts and white parts of the picture.
a. brightness
b. hue
c. contrast
d. illumination
93. The stereophonic subcarrier suppression
level in the Philippines standards
a. less than 4% modulation of the main
carrier
b. less than 3% modulation of the main
carrier
c. less than 2% modulation of the main
carrier
d. less than 1% modulation of the
main carrier
94. The sound IF in a TV receiver is
a. 4.5 MHz
b. 10.7 MHz
c. 41.25 MHz
d. 45.75 MHz
95. The circuit the separates sync pulse from the
composite video waveforms is
a. the keyed AGC amplifier
b. a clipper
c. an integrator
d. a differentiator
96. In the CED system, the disk capacitance
varies with the
a. pit depth
b. disk size
c. speed of rotation
d. wavelength of the scanning light
97. The final power amplifier in an FM
transmitter usually operates class ______.
a. AB
b. C
c. B
d. A
98. In a picture tube, it is the total angle that the
beam can be deflected without touching the
sides of the envelope.
a. screen angle
b. tube angle
c. picture angle
d. deflection angle
99. It is necessary to time the scanning with
respect to picture information
a. flyback
b. synchronization
c. blanking
d. scanning
100. The intermediate frequency used in for
FM broadcasting Philippine standards.
a. 455 kHz
b. 10.7 MHz
c. 11.4 MHz
d. 12.5 MHz