This is the Section 5 Module 17 of the compiled Communications Coaching Materials taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies (EST), Communications Books, Journals and other Communications References. This particular Coaching Notes in Communications Engineering has random Questions and Answers in random topics. Make sure to familiarize each questions to increase the chance of passing the ECE Board Exam.
Communications Engineering Coaching: Section 5 Module 17
1. ATM used for video, voice and distance learning application where time is important
Constant bit rate
2. ATM service used where no service guarantees are required (email and file transfer)
Unspecified bit rate
3. ATM used for applications that require data transfer and distributed file service
Available Bit rate
4. ATM used for applications having end systems that can recover from variable traffic rats and small cell losses
Real-time Variable Bit Rate
5. Transferred electron bulk occurs in
Gallium Arsenide
6. Tropospheric scatter
UHF
7. IRIDUIM satellite network has how many spot beams?
48
8. Booth for TV observers (sponsors and VIPs)
Fish bowl
9. Frames per second in the US TV system
30
10. Intercarrier frequency in US color TV system
4.5 MHz
11. Number of lines per field in the US TV system
262.5 MHz
12. Lines per second in US TV system
15 750
13. Channel width in US TV system
6 MHz
14. Sets the standard for the computer languages, electrical specifications, communication protocol, etc.
ANSI
15. Threshold current of laser
50 mA
16. International standard for optical connector and all the test standards
IEC
17. What IEC laser classification is very dangerous that even reflections are hazardous and the direct beam can cause fires and skin injury?
Class 4
18. What IEC laser classification where visible lasers with output within the visible spectrum of 400 to 700 nm can be found?
Class 2
19. Normal operating current of lasers used in FO
70 mA
20. Frames shorter than 64 bytes, invalid for Ethernet network
Runts
21. VF channel passband
0 – 4000 Hz
22. Electronic equipment that connects the downlink to the receiving site
Final mile or last mile
23. Electronic equipment that connects point of origin to the uplink
First mile
24. Asynchronous transmission has low-speed transmission less than ____kbps.
2.4
25. Nominal value of the dial pulse break interval in millisecond in the US is
60
26. To separate channels in TDM
AND gate
27. Difference between sound carrier and color subcarrier frequency
0.92 MHz
28. PIN diode
Microwave switch
29. In ISDN, what H-channel is designed for a variety of user-information functions, including enhanced video, compressed high definition television and telecasting?
H4-channel
30. In ISDN, how many more times is the speed of the H-O channel compared to the B-channel rate?
6
31. Category of ISDN digital services supports transfer of information without the network knowing or manipulating the content of the information?
Bearer services
32. ISDN assigned to telemetry and packet switched data
C-Channel
33. What category of ISDN digital services act at layer 4 to 7 of the OSI model and accommodate more complex data transfer needs?
Teleservices
34. The ISDN B-channel, which carries the subscriber communication, operates at what synchronous data rate?
64 kbps
35. GG is a CATV hyperband channel. What is its frequency band
336 – 342 MHz
36. A unit of luminance and a measurement of reflected brightness, used in describe light output of projection TV screens
Foot Lambert
37. When an electromagnetic waves are reflected at an angle from a wall, their wavelength along the wall is _____ the actual direction of propagation.
Greater than
38. In loose tube fiber design, optic fiber is up to _____ longer than the tube.
1%
39. Non-resonant antenna
Rhombic antenna
40. In negative transmission, what is the relative amplitude of the modulated picture carrier wave for maximum white?
12.5%
41. In negative transmission, what is the relative amplitude of the modulated picture carrier wave for black in the picture?
67.5%
42. In negative transmission, what is the relative amplitude of the modulated picture carrier wave for blacking level?
75%
43. In negative transmission, what is the relative amplitude of the modulated picture carrier wave for the tip of sync?
100%
44. The baud rate is equal to ______ the bandwidth in ideal channel.
twice
45. In satellite communication, what is the most powerful and popular subset of linear block codes because encoding and decoding can be implemented by using simple shift registers?
Cyclic code
46. Firewire developed by Apple Computer
IEEE 1394
47. What international standard for structured cabling concentrates on system and methods?
ISO
48. In synchronous network, what is recognized international standard?
SDH
49. CATV midband channel
H
50. FCC zones govern the separation of broadcasting stations within each zone. In zone 1, the minimum co-channel separation is ______ miles for VHF channels and ________ miles for UHF.
170, 155
51. Important class of nonbinary BCH class code in which the symbols are blocks of bits
Reed-Solomon code
52. GIF compression is lossless, supports transparency but allows a max of _____ colors only
256
53. What type of transmitter has been replaced by the use of microphones in many modern telephones?
Carbon
54. Switching system improves the _____ of the data transfer.
Efficiency
55. Gray scale is usually divided into ______ steps.
10
56. EBICON
Electron Bombardment Induced Conductivity
57. Multitone ringing generator
Anti-tinkle Circuitry
Output amplifier
Tone generation
58. ISDN channel type is reserved conventional analog telephone communication
A-Channel
59. Circuit that conform to ITU-T recommendations G.703 and G.704 for a primary rate operating at 2.048 Mbps?
CEPT-E1
60. FDDI
100 Mbps
61. For low attenuation, the best transmission medium is _____ waveguide.
Rectangular
62. A 35mm frame of film that measures 36 x 24 mm has aspect ratio of ____.
3:2
63. CATV midband channel range
162 – 168 MHz
64. The wavelength of a wave in a waveguide is _______ in free space.
Lesser than
65. Key element for both ISDN access and Intelligent Network Access
Signaling
66. What internet firewall uses the IP address and TCP port number to decide if a packet can pass through the routers?
Packet filter
67. What Internet Firewall uses a comparison-based where a packet technique under filtering is compared with the saved state of the previously forwarded packets?
Dynamic Firewall
68. Basic group B
60 – 108 MHz
69. Horizontal scan rate for NTSC system
15.734 KHz
70. Public-key encryption method used for email
Pretty Good Privacy (PGP)
71. Video Conferencing standard for PSTN
H.320
72. Multiband HF antenna
Log periodic antenna
73. Microwave link repeaters are typically ______ apart because of earth curvature
50 km
74. Latency in voice communication ... delay over
100 ms
75. Horizontal scan rate for the NTSC system
63.556 ms
76. Protocols may be ______ oriented
Bit, character, byte
77. If the antenna diameter in a radar system is increased by a factor of 4 the maximum range will be increased by a factor of ____.
4
78. What laser specification is quoted only in a typical value?
wavelength
79. In FO, ________-size cables have counts increasing in multiples of 6 or 8 to give sizes of 12, 18, 24, 30 and 36.
medium
80. E4 bit rate
139.264 Mbps
81. Microprocessor require in order to work with a telephone circuit
ROM and RAM
82. The operating temperature of lasers in FO is typically from ______ to ______ degrees Celsius.
-5, 65
83. How many different tones may be produced by a 4-column keypad?
16
84. Filter used for SSB generation
Mechanical
85. Bit rate of frame alignment of E1 system
28 kbps
86. Symmetrical DSL was developed to provide high speed communications on a single cable pair, but at distances n greater than ________ feet.
10,000
87. Max deviation of FM sound signal
25KHz
88. Pretty Good Privacy(Internet security) based on
Rivest-Shamir Adleman Algorithm
89. # of Unique tones for a 12-key dual-tone multi-frequency keypad
7
90. Typical response time of light detector in FO
3.5 ns
91. Antenna best excited by waveguide
Horn
92. Transport capacity of SONET virtual tributary frame (VT1.5)
1.728 Mbps
93. Percent power saving, if carrier of a 100% modulated AM is suppressed
66.66%
94. What category of ISDN digital services adds an additional layer including reverse charge, call waiting, message handling and etc.
Supplementary Services
95. Transfer electron bulk modulus occurs in ______________.
Gallium Arsenide
96. In radar, the transmitter power is increased by a factor of 16, the maximum range will be increased by a factor of __________.
2
97. Iridium satellite network has _____ number of spot beams?
48
98. What are the functions provided by the multi-frequency ringer generator?
Output Amplifier, Tone Generator, Anti-Tinkle
99. The voice frequency channel passband?
0-4000Hz
100. Normal operating current of laser in fiber optics.
70mA
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