This is the Section 2 Module 1 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 2 Module 1
1. It is the scientist who is engaged in the study in the field of acoustics
ANSWER: Acoustician
2. Who coined the term "cyberspace?"
ANSWER: William Gibson
3. For educational purposes, who is the person who first discovered/ invented the telephone?
ANSWER: Antonio Meucci
4. What is the frequency of the middle C?
ANSWER: 262 Hz
5. What is the frequency of the upper side/ above middle C?
ANSWER: 524 Hz
6. It is the loudness level (in PHON) of a watch ticking.
ANSWER: 20 PHON
7. What is the maximum limit time of exposure on sound levels between 100 dB and 110 dB?
ANSWER: 20 minutes
8. What is the colloquial name for the term "Thin Ethernet"?
ANSWER: Cheapernet
9. Local Multipoint Distribution Service (LMDS) operates at what frequency range?
ANSWER: 27 - 31 GHz
10. A video signal that has no sync signal is what you called
ANSWER: Non-composite Video Signal
11. It is the gas that is used in jet engines.
ANSWER: Hydrazine
12. A satellite is put into final geosynchronous orbit from its transfer orbit by firing the __________.
ANSWER: apogee kick motor
13. A terrestrial communications channel linking an earth station to a local switching network or population center
ANSWER: Backhaul
14. Polytetrafluoroethylene is also known as
ANSWER: Teflon
15. For SSB transmitter, the average power is typically __________ of the peak envelope power, with a typical human speech
ANSWER: ¼ to 1/3
16. It is often called text messaging, is a means of sending short messages to and from mobile phones.
ANSWER: The Short Message Service (SMS)
17. North American type of sound file as a substitute for MP3
ANSWER: AC-3 Dolby
18. A table showing the pre-calculated position of satellite at any given time
ANSWER: Ephemeris
19. How many Horizontal scanning lines are there in HDTV?
ANSWER: 1125
20. How long that a GPS satellite completes its orbit?
ANSWER: 12 hrs
21. What is the other term for parity check?
ANSWER: Vertical Redundancy Check
22. What is the other name for single button microphone?
ANSWER: Carbon Button
23. Instrument that is used in measuring the virtual height of ionosphere
ANSWER: Ionosonde
24. An instrument used to measure relative height, layers in the ionosphere regarding wave propagation?
ANSWER: Ionosonde
25. In a trapezoid modulation, 100% modulation will result to what waveform?
ANSWER: triangular waveform
26. It is the type of navigation that is based in Newton's Law of motion
ANSWER: Inertial Navigation
27. What type of navigation system that currently used in aircraft, submarines, spacecraft and guided missiles.
ANSWER: Inertial Navigation System
28. What is the successor of Bluetooth?
ANSWER: Lisbon
29. What is the successor of Bluetooth after Lisbon?
ANSWER: Seattle
30. Carrier freq is also known as
ANSWER: rest freq
31. Who developed the superheterodyne receiver
ANSWER: Edwin Armstrong
32. When the angle of incidence is equal to the angle of refraction, the light in the fiber optics is in what direction
ANSWER: along the normal path
33. What refers to the sampling of analog signal using a sample and hold circuit, such that the sample has the same amplitude for its whole duration
ANSWER: flat top sample
34. What is the antenna height of a CB (Citizen Band) radio?
ANSWER: 60 ft above the ground and 20 above the building
35. What is the nearest star in the solar system
ANSWER: proxima centauri
36. A rocket has two satellites, the smaller will continue to propel in the space after the bigger satellite has been launched. What do you call this bigger satellite
ANSWER: initial payload
37. What antenna is used in radar?
ANSWER: horn with parabolic reflector which rotates 360 degree
38. What is the distance which needs a repeater in the microwave communication
ANSWER: 40 km
39. Terrestrial microwave antennas has an input and output impedance of ________ ohms.
ANSWER: 50
40. Radio format that uses Mpeg 4 video compression
ANSWER: Divx
41. What is the typical value of velocity factor of an open wire transmission line?
ANSWER: 0.9
42. Type of resistor use to reduced flicker noise voltage (0.02 to 0.2 mV)
ANSWER: metal film
43. In 2002, a standard for (BWA) Broadband Wireless Access was introduced and in the IEEE standard it is more commonly known as 802.16. This also refers to
ANSWER: WiMax
44. The current digital video specification that used video compression
ANSWER: MPEG 4
45. 802.15.4 also known as
ANSWER: Zigbee
46. In radio communication, what is the point on a line between the earth’s center and an observer, located further from the earth’s center on a point?
ANSWER: Nadir
47. A camera tube that is formed from lead oxide (PbO)
ANSWER: Plumbicon
48. What part of visible spectrum where camera pick up that has the greatest output?
ANSWER: Yellow Green
49. In a telephone channel, if the total via net loss of a given trunk circuits exceeds approximately 2.5 dB, a device known as ___________ is inserted.
ANSWER: Echo Suppressor
50. In CMTS, the frequency separation between forward and reverse channel is
ANSWER: 45 MHz
51. Helical antennas are often used for satellite tracking at VHF because of the
ANSWER: Faraday effect
52. What formula is used to calculate the overall noise performance if receiver or of multiple state of RF amplification?
ANSWER: Friis Formula
53. What is IEEE standard for WiFi?
ANSWER: 802.11b
54. High definition TV picture contains about 5 times as much info as the present NTSC TV.
55. Communication antenna used with rotating satellite which the antenna is continuously adjusted with respect to the satellite so that the antenna illuminates a certain part of the earth surface.
ANSWER: Despun antenna
56. An acoustic scale whose intervals are exactly consonant
ANSWER: diatonic
57. What is the typical value of velocity factor of a twin lead transmission line?
ANSWER: 0.8
58. What is the typical value of velocity factor of a open wire transmission line?
ANSWER: 0.9
59. Radio blackout on the entire sunlit side of the Earth lasting for a number of hours
ANSWER: R5
60. Severe HF radio communications blackout occurs mostly on the sunlit side of Earth for one to two hours
ANSWER: R4
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