This is the Miscellaneous Multiples Choice Questions Part 6 of the Series in Communications Engineering. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including past Board Questions in Communications Engineering field (Electronics Systems and Technologies). In the actual board, you have to answer 100 items in Electronic Systems and Technologies within 5 hours. You have to get at least 70% to pass the subject. Electronic Systems and Technologies is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Engineering (30%).
Practice Exam Test Questions
Following is the list of multiple choice questions in this brand new series:
Continue with Part VI of the Series
Choose the letter of the best answer in each questions.
251. The thick coaxial cable implementation of standard Ethernet.
- a. 1000 Base-T
- b. 10 Base-T
- c. 10 Base-2
- d. 10 Base-5
252. Jitter is term used to magnify phase shifts of the information transmitted. Jitter above 10Hz is called ______.
- a. Alias
- b. Impulse
- c. Wander
- d. Parity
253. The NRZ digital signal-encoding format has a ______ component in the waveform.
- a. Dc
- b. Sinusoidal
- c. Harmonic
- d. Parity
254. It is a four wire Gigabit Ethernet implementation
- a. 1000 Base-SX
- b. 1000 Base –LX
- c. 1000 Base-T
- d. 1000 Base-CX
255. Codes that have a restriction on the number of consecutive 1s or 0s in a sequence.
- a. Fixed weight code
- b. Linear Block codes
- c. Systematic code
- d. Run length code
256. In digital broadcasting standards, MPEG1 compression uses a technique in which each 8x8 block is encoded by first applying ___ and then a quantization process.
- a. Progressive scanning
- b. Fourier Transform
- c. Discrete Cosine Transform
- d. Progressive Transform
257. In antenna mast or tower construction, the required obstruction painting and/or lighting must be imposed on mast or tower more than ___ from the ground level.
- a. 100 ft
- b. 150 ft
- c. 200 ft
- d. 250 ft
258. The AT&T T1 lines
- a. use 16-bit PCM code and include 24 voice channels
- b. use delta modulation and include 48 voice channels
- c. use 8-bit PCM code and include 24 voice channel
- d. use delta modulation and include 24 voice channels
259. What term is used in asynchronous transfer mode (ATM) system to describe a byte?
- a. Harmonic
- b. Octet
- c. Octave
- d. Bit
260. In FDM, how many mastergroups constitute a Jumbo group?
- a. 6
- b. 12
- c. 10
- d. 8
261. Reed-Solomon codes utilize a technique called ___ to rearrange the data into a nonlinear ordering scheme to improve the chance of data correction.
- a. Pseudorandom
- b. BSC
- c. Interleaving
- d. Quantizing
262. In April 2002, the IEEE published their 802.16 standard for “broadband wireless access” (BWA), more commonly known as:
- a. WIMAX
- b. Zigbee
- c. Wi-Fi
- d. Bluetooth
263. An ordinary SIM card used in most cellular phones today has a typical dimension of _______.
- a. 10x15mm
- b. 20x25mm
- c. 15x10mm
- d. 25x15mm
264. The operating frequency range of low frequency CATV amplifier.
- a. 1 Hz to 150MHz
- b. 10 to 100 MHz
- c. 10 to 150 MHz
- d. 1 Hz to 100 MHz
265. Contains seven bytes (56bits) of alternating 0s and 1s that alert the receiving system to the coming frame and enable it to synchronize its input timing.
- a. Padding
- b. Preamble
- c. CRC
- d. Signalling
266. The central office detects a request for service from a telephone by:
- a. a flow of loop current
- b. no loop current
- c. a ringing signal
- d. dial pulses
267. As per Philippine standard, what is the minimum frequency separation in any service area for adjacent AM radio stations?
- a. 40 kHz
- b. 200 kHz
- c. 36 kHz
- d. 300 kHz
268. In acoustics, it is a measure of sound pressure (dB SPL), over the frequency spectrum, for which a listener perceives a constant loudness when presented with pure steady tones.
- a. Equal-loudness Contour
- b. Loudness
- c. Even-Intensity Level
- d. Even-Pitch control
269. Class of switching office which is the local exchange where the subscriber loops terminated and received dial tone.
- a. Class 5
- b. Class 4C
- c. Class 3
- d. Class 1
270. It is the interdisciplinary study of the structure of regulatory systems and closely related to control theory and systems theory.
- a. Biometrics
- b. Aerospace
- c. Cybernetics
- d. Astrodynamics
271. What is the bit rate of STS-1?
- a. 51.84 Mbps
- b. 64 kbps
- c. 100 Mbps
- d. 2.4Ghz
272. A multiplexer combines four 150kbps channels using a time slot of 5bits, determine the frame duration.
- a. 33.33 us
- b. 3.33 us
- c. 53.33 us
- d. 1.33 us
273. Using 802.11 legacy, the maximum data rate is ___.
- a. 11 Mbps
- b. 2 Mbps
- c. 64 Mbps
- d. 8 Mbps
274. A telephone signal takes 6ms to reach its destination. Calculate the via net loss required for an acceptable amount of echo.
- a. 4.4 db
- b. 1.6 db
- c. 0.4 db
- d. 0.8 db
275. 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
276. Non regular advertisements are commonly called
- a. casual plug
- b. t-plugs
- c. back-to-back announcements
- d. traditional advertisements
277. A signal at the input to a mu-law compressor is positive with its voltage one-fourth of the maximum value. What proportion of the maximum output voltage is produced?
- a. 0.786 Vmax
- b. 0.876Vmax
- c. 0.867 Vmax
- d. 0.752 Vmax
278. Class B FM broadcast stations in the Philippines are to limit the height of the antenna to ___ above average terrain.
- a. 500 ft
- b. 200 ft
- c. 100 ft
- d. 400 ft
279. A ___ converts information from non-ISDN format to ISDN format?
- a. TE1
- b. TE2
- c. TA
- d. NT1
280. A classification of telephone system using PCM and TDM
- a. T1
- b. S1
- c. B1
- d. K1
281. A block coding technique in which four bits are encoded into a five bit code.
- a. Baudot
- b. 2B1Q Encoding
- c. 4B/5B Encoding
- d. 4A/BA Encoding
282. In negative transmission what is the relative amplitude of the modulated picture carrier wave for black in the picture?
- a. 12.5%
- b. 67.5%
- c. 75%
- d. 100%
283. The high frequency range of CATV amplifier.
- a. 300 MHz to 50,000 MHz
- b. 500MHz to 50,000 MHz
- c. 500MHz to 30,000 MHz
- d. 300MHz to 30,000 MHz
284. Telephone switch that connects only to other switches, and not to individual customers.
- a. central office
- b. toll station
- c. tandem office
- d. PSTN
285. For Ethernet system with a length of 3.5km on coaxial cable with a velocity factor of 0.65. What is the propagation delay?
- a. 12.6 us
- b. 8.33 us
- c. 17.95 us
- d. 13.88 us
286. What kind of microphone used in broadcasting that needs a tiny amplifier built in it called the head amp?
- a. Condenser microphone
- b. Spider microphone
- c. Cardiods Microphone
- d. Carbon Microphone
287. What is the maximum power allowable for remote pick-up stations used as broadcast auxiliary services for AM and FM broadcast stations.
- a. 10 W
- b. 15 W
- c. 35 W
- d. 200 W
288. Given the pulse spreading constant equal to 10ns/m and the cable length equal to 100 meters, determine the maximum bit rate in Mbps for UPNRZ transmission.
- a. 500Mbps
- b. 1.0Mbps
- c. 1000Mbps
- d. 0.5Mbps
289. A set of charts used in color TV to verify hue, brilliance and chroma.
- a. Hunsell Color Scale
- b. Munsell Color Scale
- c. Runsell Color Scale
- d. Dunsell Color Scale
290. What is the typical output voltage of magnetic microphone?
- a. 100 mV
- b. 1 mV
- c. 150 mV
- d. 15 mV
291. How long does it take to horizontally scan 550 pixels?
- a. 62.5 us
- b. 53.5 us
- c. 68.75 us
- d. 52.75 us
292. The ITU-T recommendation for error detection and correction for asynchronous transmission.
- a. V.41
- b. V.43
- c. V.42
- d. V.40
293. This OSI layer is responsible for network availability, data storage and processor capacity. It also determines the type of dialogue available.
- a. Session Layer
- b. Network Layer
- c. Data Layer
- d. Transport Layer
294. What frequencies would be generated by a telephone using DTMF signalling, when the # key is pressed?
- a. 697 Hz and 1633 Hz
- b. 941 Hz and 1477 Hz
- c. 852 Hz and 1336 Hz
- d. 941 Hz and 1209 Hz
295. The 802.11b and 802.11g divide the 2.4GHz spectrum into how many overlapping, staggered channels whose center frequencies are 5MHz apart?
- a. 13
- b. 14
- c. 15
- d. 16
296. Indicate which of the following is not a submarine cable
- a. TAT-7
- b. INTELSAT V
- c. ATLANTIS
- d. CANTAT 2
297. In negative transmission, what is the relative amplitude of the modulated picture carrier wave for maximum white?
- a. 12.5%
- b. 67.5%
- c. 75%
- d. 100%
298. What is the aural carrier for channel 6?
- a. 87.75 MHz
- b. 81.75 MHz
- c. 65.75 MHz
- d. 59.75 MHz
299. In acoustics, ___ is generally used as a standard in tuning.
- a. A (la)
- b. C (do)
- c. E (mi)
- d. G (sol)
300. The first fixed-length character code developed for machines rather than for people.
- a. ASCII code
- b. Gray code
- c. EBCDIC code
- d. Baudot code
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