Communications Engineering Coaching Materials: Section 5 Module 20

This is the Section 5 Module 20 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 20

QUESTIONS	ANSWERS
1.       A parabolic antenna in which the feed radiator is mounted at or behind the surface of the concave main parabolic reflector dish.	Cassegrain antenna
2.       The downlink frequency or base station to mobile station frequency band in GSM 1800.	1805-1880 MHz
3.       The nominal channel spacing of time division duplexing (TDD).	5 MHz
4.       In the IS-95A cellular service, the base station transmit frequency is ___ above the mobile station transmit frequency.	45 MHz
5.       The installation tension that can be given to a lightweight internal cable without causing damage.	100 N
6.       Class B-1 FM broadcast stations with an authorized transmitter power of 500 watts, shall in no case have an effective radiated power lower than ____.	1000 W
7.       The fiber number that has the typical color of orange in multi-core fiber cables.	orange
8.       The installation tension that can be given to a more rugged fiber cable without causing damage.	10000 N
9.       Aqua is the typical color of fiber number ___ in a multi-core fiber.	12
10.    A signaling path provided by a cable television system to deliver to subscriber terminal signals that are intended for reception by equipment other than a television broadcast receiver only when used with auxiliary equipment.	Class III
11.    The time it takes to transmit 1000 kbps graphic image via a 10 Mbps cable modem.	60 seconds
12.    A proprietary channel bonding equipment that can boost network up to 108 Mbps in the Wi-Fi world.	Super G
13.    In cable television, the receiving antenna should be cut to respective channel frequency for optimum reception with a front-to-back ratio not less than ___dB	18
14.    The ideal reverberation time of which is 0.8-1.2 s	Cinema
15.    What should be avoided inside an acoustical room?	Long echoed voice
16.    One of the sources of errors of GPS signal is ionospheric effect which contributes ___ of error.	+/- 5 m
17.    The first Atlantic telephone cable to use optical fiber that went into operation in 1988.	TAT-8
18.    When placing cardiods-patterned microphones, each microphone should be at least four times as far as from the next one as it is from the sound source. This is known as a ___ rule.	4-to-1
19.    The ITU-T recommendation for data compression that was issued in 1990 and uses the Limpel-Ziv Welch compression algorithm.	V.42bis
20.    A TV broadcast mainly used in Western Europe.	PAL B/G
21.    A tape format used in video recording that has a track scanning rotation seep of 1800 rpm.	Hi8
22.    The error correction code used by digital video cassette (DVC).	REED-SOLOMON CODE
23.    In composite video signal measurement, what corresponds to 0 IRE value?	Blanking pulse
24.    In composite video signal measurement, what corresponds to 100 IRE value?	Pure white
25.    The equation for luminance for TV.	0.3R-0.59G+.11B
26.    The TV standard which tends to replace PAL/SECAM in Europe.	DVB-T
27.    At what channel does superband cable television starts.	Channel 23
28.    The aural deviation for television.	+/- 25KHz
29.    A3A is previously known as _____, reduced carrier.	R3E
30.    It has the compression of 200:1.	MPEG 2
31.    In microwave communications, the maximum obstruction which a microwave link can overcome.	40%
32.    In Hamming code, there are ___ bits and ____ bits for each parity checking.	4, 3
33.    How many mastergroups are there in a jumbogroup.	6
34.    This is done to digital bits of data due to circuitry action so as not to have an undesired shift.	Reduction of jitter
35.    Aperture for microwaves	10-60 m
36.    Ratio of radiographic contrast with  grid to that without a grid.	Contrast Improvement Factor
37.    Antenna used when there are LC.	Trap antenna
38.    In _____ 1G Mobile phone with the Nordic Mobile Telephone (NMT) system was introduced.	1981
39.    The "call handoff" feature was invented to allow mobile-phone users to travel during the same conversation.	1984
40.    For FM stereo, the maximum distance covered is significantly reduced, this is due to the presence of the _________ kHz subcarrier modulation	38
41.	0.45-0.55
42. Private operational fixed microwave is on the range of ________ dB.	12.2-12.7
43. Measurement for protocols.	dBx
44. Rate for the scanning of 525 lines.	1/30
45. As per Philippine standard, frequency allocation of AM Radio Broadcasting is from__________KHz.	526.5-1705
46. Type of AM which operates at nighttime under 250 W or off-air, field strength up to 140 mV/m at 1 km.	Class D
47.	15.27
48. The coding scheme which has the easiest….	BPRZ
49. The bandwidth covered by the FM for hearing.	50 Hz-15KHz
50. The most sensitive frequency for human hearing.	1-5 KHz
51. What type of curve does our ear for telephone used.	A-weighted curve
52. How many ISDN channels are there?	6
53. For a reflection of 20 dB, __% is for loss and __% is absorbed by the load.	1, 99
54. Payment for a 1 MHz bandwidth	500,000
55. Paid up capital on 3G.	100M
56. How many horizontal lines are blanked in TV?	42
57. Downlink (receiving) assigned to GPRS	28-64 kbps
58. Disadvantage of slope detection of FM	No noise discrimination
59. The next channel if there is accommodating the 88.1 MHz channel.	94.1 MHz
60. The reverberation time for clear speech.	2 secs
61. The maximum BER for 99.97%	1 in 10 ^3
62. For illuminating the transducer through the fiber, tungsten halogen lamps or broadband, ____________ light emitting diodes are suitable.	GaAlAs
63. 802.11 legacy data rates approximately	2 Mbps
64. High definition TV picture contains about __________ times as much as info as the present NTSC TV.	5
65. IMTS2000 maximum data rate for stationary user is	2Mbps
66. The process of adjusting the orbit of a geostationary satellite so that it appears to remain stationary above a point on the earth.	Station keeping
67. The wavelength commonly used on the modern long distance fiber communications system.	1550 nm
68. HDTV compare with NTSC analog.	12 to 18 dbm
69. Super refraction	Ducting
70. In microwave communication, what concepts may be used to analyze interference by obstacles near the path of a radio beam?	Fresnel zone
71.	connector
72. In data communications, a 2400 bps modem running Class 4 would appear to operate at ______ bps.	2900
73. The full IEEE 1394b specification supports optical connections up to 100 meters in length and data rates all the way to _______ gbps.	3.2
74. What wavelength has the minimum loss in optical fibers?	1550 nm
75. Fine for unauthorized servicing of mobile telephone.	5000/year
76. What is the maximum power allowable for remote pick up stations used as broadcast auxiliary services for AM and FM broadcast stations.	35 W
77. Absorption coefficient of a surface material to absorb sound energy.	0
78. It is an error-correcting code used for correcting transmission errors in synchronous data streams.	Hamming in Code
79. Variation in signal loss.	Fading
80. It is often defined as the loss incurred by an electromagnetic wave as it propagates in a straight line through a vacuum with no absorption or reflection of energy from nearby objects.	Free Space Path Loss
81. Sampling of an analog signal using a sample-and-hold circuit that the sample has the same amplitude for its whole duration.	Flat-topped Sampling
82. Caused by the difference in the propagation times of light rays that take different path down a fiber.	Acceptance Modal dispersion
83. Closely related to acceptance angle and is the figure of merit commonly used to measure the magnitude of the acceptance angle.	Numerical Aperture
84. Actual user info conveyed through the system.	Payload
85. A navigational technique that determines position by extrapolating a series of measured velocity increments.	Dead reckoning
86. Standard that describes Ethernet-type networks is	IEEE 802.3
87. The word “Base” in 10BaseT means	The cable carries baseband signals
88. The primary audio channel remained at 50Hz to 15KHz, while an additional SCA channel is frequency translated to the   _________ passband.	60 KHz to 74 KHz
89. The fastest output rate of change (baud) is also equal to ______ of the input bit rate.	½
90. The sampling process alters the frequency spectrum and introduces an error called	Aperture Error
91. Signal rate of RS 232 normally used as interface between DTE and DCE.	20 kbps
92. An AM broadcast service area in which groundwave field of 1mV/m (60 dBu) is not subjected to objectionable interference or objectionable fading.	Primary service area
93. BW for fiber optics.	900 THz
94. International frequency distress for radio telephony	2128 KHz
95.Bit rate of STS-1	51.84 Mbps
96. Telephone switch that connects only to other switches.	Tandem
97. 802.15.4 also known as	Zigbee
98. typical range of vidicon dark current	0.2 microampere
99.Shifting of antenna pattern so that the major lobe is at angle below the horizontal.	Down tilt
100. Ethernet system that uses a special “Thick Ethernet”	A standard classical

Complete List of Communications Engineering Coaching Materials

Communications Engineering Coaching Materials

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