Communications Engineering Coaching Materials: Section 5 Module 9

This is the Section 5 Module 9 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 9

#	Questions	Answers
1	current frequency band given most attention for Satellite Communications	Ku
2	X-rays	30 to 0.3 Angstorms
3	space diversity transmission means transmitting and receiving on ______	two or more antennas operating on the same frequency
4	Ship-to-ship communications system is plagued by fading. Best solution seems to be the use of	Frequency Diversity
5	American concert pitch A is equivalent to	440Hz
6	International concert pitch A is equivalent to	435Hz
7	d band	2.20 to 3.30
8	lowest layer of ionosphere	D
9	highest layer of the atmosphere	Ionosphere
10	don't disappear at night	F2
11	next lowest layer	E
12	highest layer	F2
13	velocity factor of coaxial cable	0.6 to 0.8
14	velocity factor of transmission lines	0.5 to 0.9
15	government and military communication	NITA
16	related to mental processes of knowledge, reasoning, memory, judgment and perception	Cognitive
17	for navigation as well as marine and aeronautical communications and radar, ____ band is used	L
18	accepted official dimension of a mini-DV cassette package used in video recording in millimeters	66x48x12.2
19	NTC memorandum circular governs the rules and regulations about the manufacture, acquisition, sale and service of radio communication equipment	MC no. 02-05-88
20	a radio frequency in the UHF band of the radio spectrum	0.31250 GHz
21	when a space-wave signal passes over a mountain ridge, a small part of the signal is diffracted down the far side of the mountain	knife-edge diffraction
22	angle of inclination of GPS system	55°
23	bending of radius for fiber optic	350 mm
24	an analog video signal that carries the video data as two separate signals (brightness and color) is called	S-Video
25	a satellite beam that covers almost 42.4% of earth’s surface	global beam
26	V.42	link access protocol modem
27	multiple access technique used in GSM cellular system	TDMA
28	Connector is popular in attaching test instruments like oscilloscopes, frequency counters, spectrum analyzers.	BNC
29	to increase the transmission distance of UHF signal	increase antenna height
30	medium used by IBM token ring network that operates at either 4 Mbps or 16 Mbps	twisted pair
31	loudness level in which permanent damage to hearing is possible	150dB
32	coaxial cable connector is at least expensive and is widely used for TV sets, VCRs and cable TV	F-type connector
33	attenuator which connects passive two-ports	Calibration
34	primary cause of ionization	Ultraviolet Radiation
35	increase in sound level commonly perceived by most people	6 to 10 dB
36	sound pressure level if RMS sound pressure is 100microbars	114dB
37	coaxial connector is a more complex and expensive but do a better job in maintaining the electrical characteristics of the cable through the interconnections	N-type connector
38	PCS(personal communication system)	50 kHz
39	cocktail-end	binaural discrimination
40	capture effect	FM
41	acoustic behavior of gases	all of the choices (density, temperature, pressure)
42	spectrum bandwidth of a single GSM carrier	200kHz
43	noise figure having lowest noise	1.6dB
44	transistor having lowest noise figure	MESFET
45	noise outside the solar system	cosmic noise
46	ECT can apply for registration without examination	5years
47	ionosphere propagate by	space wave
48	maximize the skip distance	using the smallest possible radiation angle and highest possible frequency
49	space diversity	two or more antennas on the same wavelength
50	frequencies in the UHF range propagate by means of	space waves
51	VLF waves are used for some types of services because	they are very reliable
52	greatest advantage of FM over AM	FM amplitude is constant at all times
53	Companding	correlation
54	PCS(personal communication system)	45MHz
55	sound characteristic relates to a sonic time pattern	rhythm
56	typical center frequency spacing between adjacent channels (transponders) in satellites	40 MHz
57	orbital period of GPS constellation	12hrs
58	radiowave that is far from its source	plane wave
59	electric field that lies in a plane parallel to the surface of the earth	horizontal polarization
60	reference tone level for dBa	-85dBm
61	midband channel A-1	108 to 114 MHz
62	Huffman coding character contains bits	from 4 to 11
63	modulation technique used in data communications that is a variant of QAM that includes a method for forward error correction	trellis coding modulation
64	series modulation	system capable of generating high power
65	cellular standard known as the cdmaOne	IS-95
66	medium range	the one supported by IEEE 802.11 recommendation
67	most often used for outer covering of coaxial cables	PVC
68	Ethernet system is restricted only to 100m	10baseT
69	principal musical intervals is considered dissonant	7:8
70	light traveling in air optical fiber follow	snell
71	shortest wavelength in colors of light rays	blue
72	each point on a spherical wavefront may be considered a source of secondary spherical wavefronts	Huygen’s Principle
73	high frequency sound that cannot be heard by the human ear	ultrasonic
74	apparent loudness level of 80dB	very loud
75	ionoshpere causes radio signals to be	refracted
76	amount of sound reduction provided by a barrier-wall,floor or ceiling	transmission loss
77	perceptible sound repetition	echo
78	dispersion is the term used to describe	splitting of white light into its component colors in reflection
79	velocity of sound in air at 0 degrees Celcius	331.5m/s
80	in electromagnetic waves, polarization means	physical orientation of electric field in space
81	typical temperature range for installing fiber optical cable	-40 to 80 °C
82	station located on an object which is beyond and is intended to go beyond the major portion of the earth’s atmosphere	space station
83	atmospheric noise becomes less severe at frequencies	above 30MHz
84	a device that measures the internal open circuit voltage	psophometer
85	if the transmitter power remains constant, an increase in the frequency of the sky wave will	lengthen the skip distance
86	a light ray enters one medium from another along the normal. The angle of refraction is	dependent on the indexes of refraction
87	two directional antennas are pointed so that their beams intersect in the troposphere	troposcatter
88	run-length encoding	compress
89	best viewing distance of TV screen is ____ times the picture height	4 to 8
90	dielectric constant of polyethylene (PE) insulator	2.27
91	typical loudness level of an acoustic guitar 1 foot away	80 dB
92	IS-95	9.6kbps
93	satellite speed increases and its height in orbits gets ____	lower
94	satellite subsystem monitors onboard conditions such as temperature and battery voltage and transmits this data back to a ground station for analysis	TTC
95	normally associated with specifying the location of celestial body in space	ephemeris
96	satellite subsystem provides stabilization in orbit and senses changes in orientation	attitude control subsystem
97	range of speech power	10 to 1000 microwatts
98	how does spatial isolation technique satellite communications avoid interference	employment of highly directional spot-beam antennas
99	polytetrafluoroethylene(PTFE) is also widely used insulator and is known as	teflon
100	in installing fiber cable, ____is a long-time use	tighter bends
101	designated as the international distress, safety and calling frequency for radio telephony for stations of the maritime mobile service when using frequencies in the authorized bands between 156 and 174 MHz	156.8 MHz

Complete List of Communications Engineering Coaching Materials

Communications Engineering Coaching Materials

---