QUESTION:As per Philippine standard, frequency allocation of AM Radio Broadcasting is from…Choices:

a. 535 to 1605 kHzb. 526.5 to 1605 kHz

c. 535 to 1705 kHzd. 526.5 to 1705 kHz

ANSWER: d. 526.5 to 1705 kHzQUESTION:Part of broadcasting in a day that refers to that period of time between 1000 UTC to 2200 UTC. UTC stands for Universal Time Coordinates.Choices:

a. daytime periodb. nighttime period

c. experimental periodd. primetime period

ANSWER: b. nighttime periodQUESTION:An AM broadcast service area in which groundwave field of 1mV/m (60dBu) is not subject to objectionable interference or objectionable fading.Choices:

a. primary service areab. secondary service area

c. intermittent service aread. none among these

ANSWER: a. primary service areaQUESTION: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.Choices:

a. 100 ft b. 150 ft c. 200 ft d. 250 ftANSWER: d. 150 ft

QUESTION:Regarding the design of AM antenna, what should be the polarization of the radiator?Choices:

a. horizontal b. vertical c. circular d. ellipticalANSWER: b. vertical

QUESTION:As per Phillipine standard, what is the minimum frequency separation in any service area for adjacent AM radio stations?Choices:

a. 40 kHz b. 200 kHz c. 36 kHz d. 300 kHzANSWER: c. 36 kHz

QUESTION:What is the maximum power allowable for remote pick-up stations used as broadcast auxillary services for AM and FM broadcast stations? Choices:

a. 10 W b. 15 W c. 35 W d. 200 WANSWER: c. 35 W

QUESTION:What is the classification of an FM station having an ERP not exceeding 30kW?Choices:

a. Class A b. Class B c. Class C d. Class DANSWER: b. Class B

QUESTION:What is the modulation used for the stereophonic subcarrier of FM composite baseband signal?Choices:

a. AM DSB FCb. AM DSB SC

c. AM SSBd. AM VSB

ANSWER: b. AM DSB SCQUESTION:What is the pilot subcarrier frequency used in FM stereophonic transmission?Choices:

a. 15 kHz b. 19 kHz c. 30 kHz d. 38 kHzANSWER: b. 19 kHz

QUESTION:The output power of an FM transmitter is 5 kW. If the power loss in transmission line is around 10 W and the antenna has a power gain of 6 dB, what is the ERP of the station in kW?Choices:

a. 5 kW b. 30 kW c. 20 kW d. 19.96 kWANSWER: d. 19.96 kW

SOLUTION (IF PROBLEM SOLVING):GANT = 6 dB = 4ERP = (5000 – 10) x 4 = 4990 x 4 = 19,960 W or 19.96 kW

QUESTION:Frequency allocation of FM broadcast in the Philippines…Choices:

a. 535 – 1605 kHzb. 88 – 108 MHz

c. 50 – 15000 Hzd. 174 – 216 MHz

ANSWER: b. 88 – 108 MHzQUESTION:What is the color TV system adopted by the Philippines?Choices:

a. NTSCb. PAL

c. SECAMd. none among choices

ANSWER: a. NTSC

QUESTION:Exact value of color subcarrier frequency (MHz) is …Choices:

a. 3.579554b. 3.579455

c. 3.580545d. 3.579545

ANSWER: d. 3.579545QUESTION:Determine the visual carrier frequency of TV channel 9.Choices:

a. 175.25 MHz b. 187.25 MHz c. 193.25 MHz

d. 199.25 MHz

ANSWER: b. 187.25 MHzSOLUTION (IF PROBLEM SOLVING):

fNLB = 174 + (N – 7)6, using Arithmetic Progressionf9LB = 174 + (9 – 7)6 = 174 + (2)6 = 174 + 12 = 186 MHz, low band frequency of channel 9fVC = 186 + 1.25 = 187.25 MHz, visual carrier frequency of channel 9

QUESTION:What is the maximum allowable ERPs for channels 7 – 13 in Metro Manila and Metro Cebu?Choices:

a. 100 kWb. 316 kW

c. 350 kWd. 1 MW

ANSWER: d. 1 MWQUESTION:At NTSC standard, the number of lines per frame = ________ lines/frameChoices:

a. 485 b. 525 c. 625 d. 585ANSWER: b. 525

QUESTION:At NTSC standard, line frequency = 15734.264 Hz. What is the equivalent line period?Choices:

a. 66.556 usec

b. 65.556 usec c. 63.556 usec

d. 64.556 usec

ANSWER: c. 63.556 usecSOLUTION (IF PROBLEM SOLVING):

fH = 15734.264 HzH = 1 / fH = 1 / 15734.264H = 63.556 x 10-6 = 63.556 usec

QUESTION:Nominal RF bandwidth of NTSC TV channel…Choices:

a. 4.2 MHz b. 4.5 MHz c. 6 MHz d. 5.35 MHzANSWER: c. 6 MHz

QUESTION:A land mobile station used for the transmission of TV program materials and related communications from the scenes of events occuring at remote points from TV broadcast station studios to TV broadcast station.Choices:

a. TV Pick-up station b. TV STL station

c. TV Inter-city Relay stationd. TV Satellite link station

ANSWER: a. TV Pick-up station QUESTION:For a total capacity of 36 Mbps and 64-QAM of digital modulation, what is the ideal RF bandwidth? Choices:

a. 4 MHz b. 5 MHz c. 6 MHz d. 7 MHzANSWER: c. 6 MHz

SOLUTION (IF PROBLEM SOLVING):For a 64-QAM, the total number of symbol combinations is 64 symbols and the number of bits to produce this is…n = log2 64 = 6 bits per symbolTherefore the ideal RF bandwidth is…BW = fB / n = 36 Mbps / 6 bitsBW = 6 MHz

QUESTION:What is the mode of radio wave propagation that utilized ionosphere as a medium of transmission and / or reception of radio signals?Choices:

a. ground wave

b. sky wave c. space wave d. all of these

ANSWER: b. sky waveQUESTION:What is the wavelength of a radio signal travelling at a frequency of 220 MHz in a coaxial line having Teflon foam as its dielectric, εr = 2?Choices:

a. 1.0 m b. 0.85 m c. 0.96 m d. 1.36 mANSWER: c. 0.96 m

SOLUTION (IF PROBLEM SOLVING):c = 3 x 108 m/sec = 300 x 106 m/secvelocity factor vf = 1 / sqrt (εr) = 1 / sqrt (2) = 0.707 = vP / cTherefore the velocity of the radio signal in the coaxial line is …vP = 0.707c = 0.707 (300 x 106) = 212,132,034.36 m/sec (or 212 x 106 m/sec approx.)so that the wavelength of the signal is …λ = vP / f = 212 x 106 / 220 x 106 = 0.963636… m or 0.96 m approx.

QUESTION:What is the angle of refraction in a Teflon (εr2 = 2) medium of a radio wave from air (εr1 = 1.0) if its angle of incidence is 45°?Choices:

a. 24° b. 26° c. 28° d. 30°ANSWER: d. 30°

SOLUTION (IF PROBLEM SOLVING):Using Snell’s Law…Sqrt (εr1) sin θi = Sqrt (εr2) sin θr Sqrt (1) sin 45° = Sqrt (2) sin θr

θr = sin-1 [(Sqrt (1) sin 45°) / Sqrt (2)] = sin-1 (0.5) = 30°QUESTION:An ionosphere layer also termed as “absorption layer” because it absorbs most of the frequencies above 100 kHz is known as the … layer.Choices:

a. D b. E c. F1 d. F2ANSWER: a. D

SOLUTION (IF PROBLEM SOLVING):The D layer has a critical frequency in the order of 100 kHz. Even MF band frequencies are absorbed by this layer during sky wave propagation particularly in AM and SW radio broadcasting.

QUESTION:As per ITU-R Recc. V.431-6 Tables 1 & 2 Wavelength Classifications, what is the classification of Super High Frequency?Choices:

a. metric b. decimetric c. centimetric d. millimetric ANSWER: c. centimetric

SOLUTION (IF PROBLEM SOLVING):SHF band: 3 GHz – 30 GHzλmax = 3 x 108 / 3 x 109 = 0.1 m = 100 cmλmin = 3 x 108 / 30 x 109 = 0.01 m = 1 cmSHF band wavelength classification is ranging from 1 cm to 100 cm. Therefore it is centimetric wave.

QUESTION:What is a diversity scheme that uses two (2) separate antennas and receivers for each single transmitter? Choices:

a. frequency diversity

b. space diversity c. angle diversity

d. quadrature diversity

ANSWER: b. space diversityQUESTION:What is a diversity scheme that uses two (2) different frequencies in a simplex path?Choices:

a. frequency diversity

b. space diversity c. angle diversity

d. quadrature diversity

ANSWER: a. frequency diversityQUESTION:What is the critical frequency of a layer if the maximum value of electron density is 2 x 106 per cm3?Choices:

a. 11 MHz b. 12 MHz c. 13 MHz d. 14 MHzANSWER: c. 13 MHz

SOLUTION (IF PROBLEM SOLVING):Nmax = 2 x 106 per cm3 = 2 x 106 x 106 per m3 = 2 x 1012 per m3

fc = 9 x sqrt (Nmax) = 9 x sqrt (2 x 1012)fc = 12.73 MHz or 13 MHz approx.

QUESTION:A radio communication link is to be established via the ionosphere. The maximum virtual height of the layer is 110 km. at the midpoint of the path and the critical frequency is 4 MHz. If the distance between the radio stations is 500 km, what is the suitable value for the optimum working frequency? Use flat terrain analysis.Choices:

a. 8.2 MHz b. 8.3 MHz c. 8.4 MHz d. 8.5 MHzANSWER: c. 8.4 MHz

SOLUTION (IF PROBLEM SOLVING):For flat terrain analysis, tan i = d/2hv

i = tan-1 [d/2hv] = tan-1 [500/2(110)] = tan-1 [2.273] = 66.25° angle of incidenceMUF = fc x sec i = fc / cos i = 4 / cos 66.25° = 4 / 0.40275 = 9.932 MHz via Secant LawOWF = 0.85 x MUF = 0.85 (9.932) = 8.4422 MHz or 8.4 MHz approx.

QUESTION:The power density is inversely proportional to the square of the distance from the source. This law is known as…Choices:

a. Faraday’s law c. Inverse Square lawb. Snell’s law d. Gauss law

ANSWER: c. Inverse Square lawQUESTION:The lowest portion of the ionosphere that is useful for long-distance communication by amateurs; about 100 to 115 km above the earth is known as the… layer. This is often termed as the Kennely-Heavyside layer.Choices:

a. D b. E c. F1 d. F2ANSWER: b. E

QUESTION:A graph which shows the radiation in actual field strength of electromagnetic fields at all points which are at equal distance from the antenna is known as…Choices:

c. Frequency Response e. Smith Chartb. Radiation Pattern d. FCC F(50,50) Graph

ANSWER: b. Radiation PatternQUESTION:The efficiency of an antenna is 82 %. Its radiation resistance is 30 Ω. What is the value of its loss resistance?Choices:

a. 75 Ω b. 15 Ω c. 12 Ω d. 6.58 ΩANSWER: d. 6.58 Ω

SOLUTION (IF PROBLEM SOLVING):η = Rd/(Rd + Rloss)0.82 = 30/(30 + Rloss)0.82 (30 + Rloss) = 30 = 24.6 + 0.82 Rloss

Rloss = (30 – 24.6) / 0.82 = 6.5854 Ω or 6.58 Ω approx.QUESTION:A phenomenon on the surface of the sun with appearance and disappearance of dark irregularly shaped areas.Choices:

a. SID b. 11-year sunspot

c. Sporadic E-layer

d. Ionospheric storms

ANSWER: b. 11-year sunspotQUESTION:What should be done to increase the transmission distance at frequencies higher than HF bands?Choices:

c. increase antenna gain e. increase transmitter powerd. increase antenna height f. increase receiver sensitivity

ANSWER: b. increase antenna heightQUESTION:Which of the following factors must be considered in the transmission of a surface wave to reduce attenuation?Choices:

a. electrical properties of the terrain c. antenna polarizationb. frequency d. all choices

ANSWER: d. all choicesQUESTION:A radio station operates at 11 meter wavelength. What is the designated band of station’s frequency?Choices:

a. MF

b. HF c. VHF d. UHFANSWER: b. HF

SOLUTION (IF PROBLEM SOLVING):c = 3 x 108 m/secλ = 11 m = c / ff = 3 x 108 / 11 = 27 MHz approx., which is within 3 – 30 MHz range designated as HF band

QUESTION:What is the total radio horizon distance between an 80 ft transmitting station and a 20 ft receiving station?Choices:

a. 53.66 km b. 53.66 mi c. 18.97 km d. 18.97 miANSWER: d. 18.97 mi

SOLUTION (IF PROBLEM SOLVING):dRH (TOT) = sqrt (2 x hT) + sqrt (2 x hR)dRH (TOT) = sqrt (2 x 80) + sqrt (2 x 20)dRH (TOT) = 18.97 mi

QUESTION:A power density of 1.57 x 10-4 W/m2 is measured 50 meters from a test antenna whose directive gain is 2.15 dB. How much power was fed into the test antenna?Choices:

a. 1 W

b. 2 W c. 3 W d. 4 WANSWER: c. 3 W

SOLUTION (IF PROBLEM SOLVING):From Inverse Square Law, PD = PR/4πd2

PR = PD x 4πd2 = 1.57 x 10-4 x 4π(50)2 = 4.93 W approx. is the radiated powerGANT = log-1 [2.15 dB/10] = 1.64PR = PFED x GANT

PFED = PR / GANT = 4.93 / 1.64 = 3.007 W or 3 W approx.QUESTION: Identical telephone numbers in different parts of a country are distinguished by their ___.Choices: a. language digits b. area codes c. central office codes d. access digits

ANSWER: b. area codes QUESTION: Telephone traffic is measured ____.Choices:

a. in erlangs c. with echo cancellers b. c. by the relative congestion d. in terms of the grade of service

ANSWER: a. in erlangs QUESTION: In a cellular telephone system, each cell site contains a ____.Choices:

a. touch tone processors c. repeater b. control computer d. direct link to a branch exchange

ANSWER: c. repeater

QUESTION: When the signal from a mobile cellular unit drops below a certain level, what action occurs?Choices: a. the cell site switches antennas c. the unit is “handed off” to a closer cell b. the call is terminated d. the MTSO increases power level

ANSWER: c. the unit is “handed off” to a closer cellQUESTION: In a cellular telephone system, group of cells is called ___. Choices: a. sector b. cluster c. site d. cell segment

ANSWER: b. clusterQUESTION: In Celluar Telephone Systems, these are transmissions from base stations to mobile units (Downlink)Choices: a. forward links b. reverse links c. TRX d. TRA

ANSWER: a. forward linksQUESTION: A CDMA mobile measures the signal strength from the base as -100 dBm. What should the mobile transmitter power be set to as a first approximation, considering - 76 dB at mobile power contol?Choices: a. 150 mW b. 200 mW c. 250 mW d. 300 mW

ANSWER: c. 250 mW SOLUTION ( IF PROBLEM -SOLVING)PT = -76 dB - PRWhere:PT = transmitted power in dBmPR = received power in dBmPT = -76 dB - PR = -76 dB – (-100dBm) = 24 dBm = 250 mWQUESTION: A telephone signal takes 2ms to reach its destination. Calculate the via net loss required for an acceptable amount of echo.Choices: a. 0.2 dB b. 0.4 dB c. 0.6 dB d. 0.8 dB

ANSWER: d. 0.8 dB SOLUTION ( IF PROBLEM -SOLVING)VNL = 0.2t + 0.4 dBWhere:VNL = minimum required via net loss in dBt = time delay in ms for propagation one way along lineVNL = 0.2t + 0.4 dB = 0.2 X 2 + 0.4 = 0.8 dBQUESTION:The typical voltage across a telephone when on-hook is: Choices: a. 48 volts DC c. 90 volts DC b. 48 volts, 20 hertz AC d. 90 volts, 20 hertz AC

ANSWER: a. 48 volts DC QUESTION:Central offices are connected by: Choices: a. local loops c. both a and b b. trunk lines d. none of the above

ANSWER: b. trunk lines QUESTION:In telephony, call blocking is:Choices: a. cannot occur in the public telephone network b. occurs on the local loop when there is an electrical power failure c. occurs only on long-distance cables d. occurs when the central office capacity is exceeded

ANSWER: d. occurs when the central office capacity is exceededQUESTION:The cable used for local loops in telephone system is mainly:Choices: a. twisted-pair copper wire c. coaxial cable b. shielded twisted-pair copper wire d. fiber-optic

ANSWER: a. twisted-pair copper wire QUESTION:In DTMF, the four vertical frequencies are ____. Choices: a. 1209Hz, 1336Hz,1477Hz,1633Hz b. 697Hz,770Hz,852Hz,941Hzc. 679Hz,770Hz, 852Hz, 941Hzd. 1208Hz,1336Hz,1747Hz,1633Hz

ANSWER: b. 697Hz,770Hz,852Hz,941HzQUESTION:In DTMF, the Horizontal frequencies areChoices: a. 1209Hz, 1336Hz,1477Hz,1633Hz b. 697Hz,770Hz,852Hz,941Hzc. 679Hz,770Hz, 852Hz, 941Hzd. 1208Hz,1336Hz,1747Hz,1633Hz

ANSWER: a. 1209Hz, 1336Hz,1477Hz,1633Hz

QUESTION: In Celluar Telephone Systems, these are transmissions from mobile units to base stations (Uplink)Choices: a. forward links b. reverse links c. TRX d. TRA

ANSWER: b. reverse links QUESTION:In DTMF, the horizontal frequencies is also known asChoices: a. low group frequenciesb. high group frequenciesc. mid group frequenciesd. top group frequencies

ANSWER: b. high group frequenciesQUESTION:In DTMF, the Vertical frequencies is also known asChoices: a. low group frequenciesb. high group frequenciesc. bottom group frequenciesd. top group frequencies

ANSWER: a. low group frequenciesQUESTION:The bandwidth of voice-grade signals on a telephone system is restricted in order to:Choices: a. allow lines to be "conditioned" c. allow signals to be multiplexed b. prevent "singing" d. all of the above

ANSWER: c. allow signals to be multiplexedQUESTION:This is the highest-ranking office in the DDD network in telephony in terms of the size of the geographical area served and the trunking options available.Choices: a. section center c. primary center b. regional center d. all of the above

ANSWER: b. regional center QUESTION:In Cellular Radio, AMPS stand for:Choices: a. American Mobile Phone System c. Advanced Mobile Phone Systemb. Analog Mobile Phone Service d. Advanced Mobile Phone Service

ANSWER: d. Advanced Mobile Phone Service QUESTION:In Cellular Radio, BSC stands for:Choices: a. Base Station Controller c. Basic Service Contractb. Base Signal Controller d. Basic Service Code

ANSWER: a. Base Station Controller QUESTION:In Cellular Radio, MSC stands for:Choices: a. Mobile Switching Center c. Maximum Signal Carrierb. Mobile Service Cellular d. Minimum Signal Carrier

ANSWER: a. Mobile Switching Center QUESTION:In GSM, voice channels are called:Choices: a. traffic channels c. bearer channelsb. voice channels d. talking channels

ANSWER: a. traffic channels QUESTION:In Mobile Communications, GSM uses:Choices: a. frequency hopping c. CDMAb. direct-sequence modulation d. all of the above

ANSWER: a. frequency hopping QUESTION:In Mobile Communications, IMSI stands for:Choices: a. Integrated Mobile Subscriber Identificationb. International Mobile Subscriber Identificationc. Interim Mobile Subscriber Identificationd. Intermodulation System Interference

ANSWER: b. International Mobile Subscriber Identification QUESTION: The angular separation between the two half-power points on the power density radiation pattern.Choices:

a. Bandwidth b .Beamwidth c. Footprint d. Azimuth ANSWER: b. Beamwidth

QUESTION:Refers to the direction in space of electric vector of the electromagnetic wave radiated from an antenna and is parallel to the antenna itself.Choices:

a. Propagation b. Coordinates c. Polarization d. AzimuthANSWER: c. Polarization

QUESTION:Placing a metallic array on the antenna effects to increase the current at the base of the antenna, and also to make the current distribution more uniform. What is this called?Choices:

a. Reflector b. Grounding c. Top loading d. FeedingANSWER: c. Top loading

QUESTION:What principle that states that the properties of an antenna are independent of whether it is used for transmission or reception.Choices:

a. Alternation b. Diplexer c. Reciprocity d. RepeatabilityANSWER: c. Principle of reciprocity

QUESTION:Calculate the beam width between nulls of a 2-m paraboloid reflector used at 6GHz. Note: such reflectors are often used at that frequency as antennas outside broadcast television microwave links.Choices:

a. 140 b. 70 c. 3.50 d. 0.8750 ANSWER: c. 3.50

QUESTION:This is often used to cure the problem of great thickness required of lenses used at lower microwave frequencies or for strong curved wavefronts.Choices:

a. Splicing b. Zoning c. Curving d. PolarizingANSWER: b. Zoning

QUESTION:A structure-generally metallic and sometimes very complex-designed to provide an efficient coupling between space and the output of a transmitter or input to a receiver.Choices:

a. Stub b. Antenna c. Transmission line d. waveguideANSWER: b. antenna

QUESTION:The ratio comparing the power density generated by a practical antenna in some direction, with that due to an isotopic antenna radiating the same total power.Choices: a. directivity b. Directive gain c. bandwidth d. Elementary doublet

ANSWER: b. Directive gainQUESTION:Any array that is directional at right angles to the plane of the array is said, by inference, to have __________.Choices:

a. Broadside b. Broadside array c. Broadside action d. End-fire arrayANSWER: b. Broadside action

QUESTION:The ratio of the focal length to the mouth diameter is called __________ of the parabola, just as in camera lenses.Choices: a. focus b. resolution c. feed d. aperture

ANSWER: d. Aperture QUESTION:Corresponds to a resonant transmission line, and the dipole antennas describe so far have been resonant.Choices: a. Non-resonant antenna b. Resonant antenna c. Antenna arrays d. None of the above

ANSWER: b. Resonant antennaQUESTION:Geostationary satellites are located at ____ with respect to the equator.Choices: a. 00 longitude b. 00 latitude c. 450 longitude d. 900 latitude

ANSWER: b. 00 latitudeQUESTION:The quality of a space-link is measured in terms of the ______ ratio. Choices: a. S/N b. G/T c. C/N d. EIRP

ANSWER: b. G/T QUESTION:Why does the downlink frequency appear to vary by several kHz during a low earth orbit satellite pass?Choices:

a. The distance between the satellite and ground station is changing, causing the Kepler effectb. The distance between the satellite and ground station is changing, causing the Bernoulli effectc. The distance between the satellite and ground station is changing, causing the Boyle’s Law effectd. The distance between the satellite and ground station is changing, causing the Doppler effect

ANSWER: d. The distance between the satellite and ground station is changing, causing the Doppler effectQUESTION:The most ambitious LEO constellation to date is ______.Choices:

a. Iridiumb. NAVSTARc. Teledesicd. Globalstar

ANSWER: c. Teledesic

QUESTION:A satellite-dish owner has a 3 meter dish designed for C-band (4 GHz) operation. The owner wants to use the same dish with a new feedhorn, for Ku-band (12 GHz) satellites. What effect will the change in frequency have on the gain and beamwidth of the antenna? Choices:

a. Gain increases by 9.54 dB, beamwidth decreases to 1/3 of its former value.b. Gain decreases by 9.54 dB, beamwidth decreases to 1/3 of its former value.c. Gain increases by 9.54 dB, beamwidth increases to thrice of its former value.d. Gain decreases by 9.54 dB, beamwidth increases to thrice of its former value.

ANSWER: a. Gain increases by 9.54 dB, beamwidth decreases to 1/3 of its former value.QUESTION:The moon orbits the earth with a period of approximately 28 days. How far away is it? Assume circular orbit.Choices: a. 380 Mm b. 382 Mm c. 384 Mm d. 386 Mm

ANSWER: c. 384 Mm QUESTION:What is the length of the path to a geostationary satellite from an Earth station if the angle of elevation is 300? Choices: a. 6400 km b. 39000 km c. 42400 km d. 46000 km

ANSWER: b. 39000 kmQUESTION:What is the nominal uplink frequency for the Ku band?Choices:

a. 6 GHzb. 4 GHzc. 14 GHzd. 12 GHz

ANSWER: c. 14 GHzQUESTION:To cover all inhabited regions of the earth, the number of polar-orbit satellites required isChoices: a. 1 b. 2 c. 3 d. 5

ANSWER: a. 1QUESTION:The highest frequency that can be used for skywave propagation between two specific points on earth’s surface.Choices: a. Critical Frequency b. MUF c. Cut-off frequency d. mid frequency

ANSWER: a. Critical Frequency QUESTION:Variation in signal loss caused by natural weather disturbances.Choices: a. attenuation b. fading c. spreading loss d. weather loss

ANSWER: b. fadingQUESTION:Determine the radio horizon for a transmit antenna that is 200 m high and a receiving antenna that is 100 m highChoices:a. 99.5km b. 96.5 km c. 95.87 km d. 97.5 km

ANSWER: a. 99.5kmSOLUTION ( IF PROBLEM -SOLVING) D = √ 17ht + √ 17hr = √ 17(200) + √ 17(100) = 99.5 kmQUESTION:The height above the earth’s surface from which a refracted wave appears to have been reflected…Choices:a. actual height b. virtual height c. average height d. mean height

ANSWER: b. virtual heightQUESTION:The highest frequency that can be used for skywave propagation between two specific points on earth’s surface.Choices:a. Critical Frequency b. MUF c. Cut-off frequency d. center frequency

ANSWER: a. Critical FrequencyQUESTION:Electromagnetic waves that are directed above the horizon level.Choices:a. ground waves b. surface waves c. sky waves d. space waves

ANSWER: c. sky wavesQUESTION:An acoustical phenomenon wherein the sound continues to persist after the cause of sound has stopped resulting in repeated reflections is called…Choices: a. echo b. reverberation c. reflection d. diffraction

ANSWER: b. reverberationQUESTION:A group of filters has 1/3 octave of spacing. If the initial frequency is 25 Hz, what is the next frequency available for the filter? Choices: a. 50 Hz b. 12.5 Hz c. 75 Hz d. 31.5 Hz

ANSWER: d. 31.5 HzSOLUTION (IF PROBLEM SOLVING):f2 = 2x f1 where x = 1/3, fraction of an octavef2 = 21/3 x 25 = 31.5 Hz

QUESTION:+ 26 dBu is how many volts? Choices: a. 7.75 V b. 15.5 V c. 31 V d. 62 V

ANSWER: b. 15.5 VSOLUTION (IF PROBLEM SOLVING):V (dBu) = 20 log [ voltage in Volts / 0.775 Volts ]26 = 20 log [ voltage in Volts / 0.775 V ]26 / 20 = log [ voltage in Volts / 0.775 V ] = 1.3Voltage = log-1 (1.3) x 0.775 VVoltage = 15.5 VQUESTION:A type of microphone that uses the principle of a capacitor as a means of transduction. It uses a polarizing voltage of between 9 and 48 V of DC supply applied to its diaphragm by an external power supply.Choices: a. Dynamic b. Condenser c. Ribbon d. Carbon

ANSWER: b. CondenserQUESTION:Determine the sound power in Watts produced by the bank’s alarm if a by-stander heard the alarm at a sound pressure level of 100 dB-SPL. The by-stander is 100 ft away from the bank. Choices: a. 56.85 W b. 55.68 W c. 58.56 W d. 58.65 W

ANSWER: d. 58.65 WSOLUTION (IF PROBLEM SOLVING):PWL = SPL + 20 log D(m) + 8PWL = 100 + 20 log (100/3.28) + 8 = 137.68 dB-PWL137.68 = 10 log W + 120W = log-1 [(137.68 – 120)/10]W = 58.65 WattsQUESTION:A loudspeaker produces an SPL of 85dB-SPL at 1 meter distance and input electrical power of 1 W. How loud is the SPL at distance of 20 meters if this speaker is driven to 10 W of electrical power?Choices: a. 82 dB-SPL b. 69 dB-SPL c. 65 dB-SPL d. 79 dB-SPL

ANSWER: b. 69 dB-SPLSOLUTION (IF PROBLEM SOLVING):SPL@1m/1W = 85 dB-SPL (given)SPL@20m/1W = 85 - 20 log (20m/1m) = 59 dB-SPLSPL@20m/10W = 59 + 10 log (10W/1W) = 69 dB-SPLQUESTION:A number from 0 to 1 representing the ability of a surface material to absorb sound energy is known as… Choices: a. Sound absorption c. Absorption Coefficient b. Reflection coefficient d. Room Constant

ANSWER: c. Absorption CoefficientQUESTION:The difference in dB between the loudest level of sound and the softest passage of sound is known as _Choices: a. Headroom c. gain b. signal-to-noise ratio d. dynamic range

ANSWER: d. dynamic rangeQUESTION:The height above mean sea level of a satellite in a geosynchronous orbit around Earth is:Choices: a. 35,786 miles b. 35,786 NM c. 35,786 feet d. 35,786 km

ANSWER: d. 35,786 kmQUESTION:The location of a satellite is generally specified in terms ofChoices: a. azimuth & elevation b. latitude & longitude c. true morth d. bearing

ANSWER: b. latitude & longitudeQUESTION:A point in the orbit of an object orbiting the earth that is located closest to Earth.Choices: a. perigee b. apogee c. apex d. subsatellite point

ANSWER: a. perigeeQUESTION:Find the velocity of a satellite in a circular orbit 500 km above the earth’s surface.Choices: a. 76 km/s b. 76 m/s c. 7.6 km/s d. 7.6 km/s2

ANSWER: c. 7.6 km/sSOLUTION ( IF PROBLEM -SOLVING)

Formula :

v 4x1011

d 6400 Where : v = velocity in meters per second d = distance above earth’s surface in km

v 4x1011

(500 6400) = 7.6 km/s

QUESTION:Find the orbital period of a satellite in a circular orbit 36,000 km above the earth’s surface if the earth’s radius is 6400 km.Choices: a. 1440 mins b. 24 days c. 3,600 sec d. 1440 sec

ANSWER: a. 1440 minsSOLUTION ( IF PROBLEM -SOLVING)

Formula :

C

vWhere : T = orbital period C = circumference v = orbital velocity C = 2r = 2 ( 6400 + 36,000 ) = 266.4 x 106 m

v 4x1011

(36,000 6400)3.07km /s

T C

v266.4x106m

3.07x103m /s24hrs

or 1440 minutesQUESTION:The outline of a communications satellite antenna pattern on the earth is known as:Choices: a. beam b. propagation pattern c. spot d. footprint

ANSWER: d. footprintQUESTION:Calculate the length of the path to a geostationary satellite from an earth station where the angle of elevation is 30.(earth’s radius = 6400 km, height of satellite above earth is 36 X 103 km)Choices: a. 36,000 km b. 36,000 mi c. 39,000 km d. 39,000 mi.

ANSWER: c. 39,000 kmSOLUTION ( IF PROBLEM -SOLVING)

Formula :

d (r h)2 (rcos)2 rsin d = distance to the satellite in km r = radius of the earth in km (6400 km) h = height of satellite above equator ( 36 x 103 km) = angle of elevation to satellite at antenna siteSolution :

d (6400 36x103)2 (6400cos30 )2 6400sin30

= 39,000 kmQUESTION:A satellite access technique where each earth station transmits a short burst of information during a specific time slot.Choices: a. FDMA b. DAMA c. TDMA d. SCADA

ANSWER: c. TDMA ( Time Division Multiple Access)QUESTION:An earth station antenna look angle is determined by :Choices: a. azimuth & elevation b. longitude & latitude c. bearing d. true north

ANSWER: a. azimuth & elevationQUESTION:An ITU radiocommunication standards for satellite services which provides information on the range of frequencies that can be used by fixed satellite service systems for emergency and disaster relief operations.Choices: a. ITU-R M1854 b. ITU-R S 009 c. ITU-R S.1001-2 d. ITU-R S.004

ANSWER: c. ITU-R S.1001-2QUESTION:A mammography service examined 327 patients during the third calendar quarter of 1996. 719 films were exposed during this period, eight of which were repeats. What is the repeat rate?Choices: a. 45.5% b. code 2.45% c. 1.1% d. 54.52%

ANSWER: c. 1.1%SOLUTION ( IF PROBLEM -SOLVING)

QUESTION:A type of luminescence where the visible light is emitted only during the stimulation of the phosphor.Choices: a. fluorescence b. phosphorescence c. after glow d. any of the above

ANSWER: a. fluorescence

QUESTION:If a heart measures 12.5 cm from side to side at its widest point, and its image on chest radiograph measures 14.7 cm, what is the magnification factor?Choices: a. 0.85 b. 1.18 c. 0.15 d. 2.2

ANSWER: b. 1.18SOLUTION ( IF PROBLEM -SOLVING)

QUESTION:Radiation doses in the range of approximately200 to 1000 rad produce theChoices: a. Gastrointestinal (GI) syndromeb. Central Nervous System (CNS) syndromec. Hematologic syndromed. Prodomal syndrome

ANSWER: c. Hematologic syndromeQUESTION:Ratio of incident to transmitted radiation through a grid ratio of patient dose with and without gridChoices: a. Bucky factor b. Damadian factor c. Grid ratio d. Roentgen equivalent

ANSWER: a. Bucky factorQUESTION:A radiographic single-phase unit installed in a private office has a maximum capacity of 100 milliseconds of 120kVp and 500mA. What is the power rating?Choices: a. 42 kW b. 60 kW c. 600W d. 24kW

ANSWER: a. 42 kWSOLUTION ( IF PROBLEM -SOLVING)

QUESTION:Who completes the development of first computed tomographic (CT) scanner (EMI, Ltd.) in 1973?Choices: a. Mistretta b. Forssmann c. Kuhl d. Hounsfield

ANSWER: d. HounsfieldQUESTION:It is the study of the response of an image receptor to x-raysChoices: a. sensitometry b. xeroradiography c. xeroradiometry d. spectrometry

ANSWER: a. sensitometryQUESTION:Ratio of radiographic contrast with a grid to that without a gridChoices: a. grid ratio b. contrast improvement factor c. Collidge factor d. Bucky factor

ANSWER: b. contrast improvement factorQUESTION:Analysis of persons irradiated therapeutically with superficial x-rays has shown that the skin erythema dose required to affect 50% of persons so irradiated is about Choices: a. 200 rad b. 400 rad c. 600 rad d. 800 rad

ANSWER: c. 600 radQUESTION:ECG recording requires a bandwidth of 0.05 to ____ HzChoices: a. 1000 b. 540 c. 100 d. 40

ANSWER: c. 100QUESTION:Find the potential generated if blood flowing in a vessel with radius 0.9 cm cuts a magnetic field of 250 G. Assume a volume flow rate of 175 cubic cm per second.Choices: a. 206 uV b. 309 uV c. 903 uV d. 260 uV

ANSWER: b. 309 uVSOLUTION ( IF PROBLEM -SOLVING)

QUESTION:Period during which heart contracts.Choices: a. Diastole b. Systole c. block mode d. Synapse

ANSWER: b. SystoleQUESTION:Apparatus for measuring blood pressureChoices: a. defibrillator b. electrocardiogram c. plethysmograph d. sphygmomanometer

ANSWER: d. sphygmomanometerQUESTION:Given the energy level of 6.624x10^-18 J imparted to an electron stream by an X-ray device, calculate the frequency in MHz.Choices: a. 10^6 MHz b. 45.29 MHz c. 10^10 MHz d. 300 MHz

ANSWER: c. 10^10 MHzSOLUTION ( IF PROBLEM -SOLVING)

10^10 MHzQUESTION:It was first noted by Heinrich Hertz in 1887 and won Albert Einstein the Nobel Prize in 1905. It refers to the emission of electrons from a clean metallic surface (phototube) when electromagnetic radiation (light waves or X-rays) falls onto that surface.Choices: a. Photoelectric effect b. Compton effect c. Bremsstrahlung d. Mie effect

ANSWER: a. Photoelectric effectQUESTION:Unit of radiation exposure or amount of X-ray radiation that will produce 2.08x10^9 ion pairs per cubic centimetre of air at standard temperature and pressure (STP).Choices: a. Curie b. Roentgen c. Radiation absorbed dose (rad) d. Gray

ANSWER: b. RoentgenQUESTION:An optical electronic device that measures the color concentration of a substance in solution. Choices: a. colorimeter b. flame photometer c. spectrophotometer d. chromatograph

ANSWER: a. colorimeterQUESTION:Recording of heart soundsChoices: a. ultracardiography b. cardioacoustics c. electrocardiogram d. phonocardiography

ANSWER: d. phonocardiographyQUESTION:Recorder for measuring galvanic skin resistanceChoices: a. electrodermograph b. electromyograph c. electrocorporealograph d. electrogalvanograph

ANSWER: a. electrodermographQUESTION:It consists of 36 unique codes representing the 10 digits and 26 uppercase lettersChoices: a. Discrete code b. code 39 c. continuous code d. 20 code

ANSWER: b. code 39QUESTION:The first fixed- length character code developed for machines rather than for peopleChoices: a. ASCII Code b. Gray Code c. EBCDIC code d. Baudot Code

ANSWER: d. Baudot CodeQUESTION:The early pioneer in the development of error-detection and correction proceduresChoices:

a. Richard W. Hamming b. William R. Hamming c. Emile Baudot d. Samuel BaudotANSWER: a. Richard W. Hamming

QUESTION:The most reliable convolutional coding scheme for error detectionChoices: a. checksum b. LRC c. CRC d. VRC

ANSWER: c. CRC

QUESTION:For the given parameters, determine the energy per bit-to noise power density ratio C = 10e-12 W fb = 60 kbps N = 1.2 x 10e-14`W B = 120 kHzChoices: a. 16.2 dB b. 14.2 dB c. 20.2 dB d. 22.2 dB

ANSWER: d. 22.2 dB SOLUTION ( IF PROBLEM -SOLVING)

; QUESTION:A signal at the input to a mu-law compressor is positive with its voltage one-half the maximum value. What proportion of the maximum output voltage is produced?Choices: a. 0.786Vmax b. 0.876Vmax c. 0.867Vmax d. 0.678Vmax

ANSWER: b. 0.876VmaxSOLUTION ( IF PROBLEM -SOLVING)

QUESTION:Inaccuracies caused by the representation of a continuously varying quantity as one of a number of discrete values.Choices: a. alias signal b. slope overload c. distortion d. quantizing errors

ANSWER: d. quantizing errors QUESTION:Circuit for digitizing voice at a low data rate by using knowledge of the way in which voice sounds are producedChoices: a. vocoder b. codec c. sample-and-hold circuit d. ADC

ANSWER: a. vocoder QUESTION:A coding scheme that records the change in signal level since the precious sampleChoices: a. unipolar code b. PPM c. PCM d. delta modulation

ANSWER: d. delta modulation QUESTION:Distortion created by using too low a sampling rate when coding an analog signal for digital transmissionChoices: a. aliasing b. foldover distortion c. either a or b d. neither a nor b

ANSWER: c. either a or b QUESTION:A network with bandwidth of 10 Mbps can pass only an average of 12000 frames per minute with each frame carrying an average of 10000 bits. What is the throughput of this network?Choices: a. 1 Mbps b. 2 Mbps c. 3 Mbps d. 4 Mbps

ANSWER: a. 2 Mbps SOLUTION ( IF PROBLEM -SOLVING)

= 2 MbpsQUESTION:A telephone subscriber line must have an SNRdB above 40. What is the minimum number of bits?Choices: a. 3.56 b. 5.63 c. 6.35 d. 3.65

ANSWER: a. 6.35 SOLUTION ( IF PROBLEM -SOLVING)SNRdB = 6.02nb + 1.76 = 40 n = 6.35QUESTION:The thick coaxial cable implementation of standard EthernetChoices: a. 1000 Base-T b. 10 Base-T c. 10 Base 2 d. 10 Base 5

ANSWER: d. 10 Base 5QUESTION:A bit pattern or a character added to the beginning and the end of a frame to separate the framesChoices: a. Flag b. Firewall c. Frameguard d. Footprint

ANSWER: a. Flag QUESTION:An IPv4 has an address space of how many?Choices: a. 4294967296 b. 6927694924 c. 2449692769 d. 9672969442

ANSWER: a. 4294967296 SOLUTION ( IF PROBLEM -SOLVING)232 = 4294967296

QUESTION:What is the bit rate of STS – 1?Choices: a. 51.84 Mbps b. 64 kbps c. 100 Mbps d. 2.4 GHz

ANSWER: a. 51.84 Mbps QUESTION:A block coding technique in which four bits are encoded into a five bit codeChoices: a. Baudot b. 2B1Q Encoding c. 4B/5B Encoding d. 4A/5A Encoding

ANSWER: c. 4B/5B EncodingQUESTION:A national standards organization that defines standards in the United StatesChoices: a. ANSI b. FCC c. ITU d. CCITT

ANSWER: a. ANSIQUESTION:In asynchronous transmission, one or more bits to indicate the end of transmissionChoices: a. trailer b. flag c. escape byte d. stop bit

ANSWER: d. stop bitQUESTION:What is the overhead (number of extra bits) in the DS-3 service? Choices: a. 1.368 Mbps b. 1.480 Mbps c. 2.048 Mbps d. 6.024 Mbps

ANSWER: a. 1.368 MbpsQUESTION:The minimum sampling rate according to Nyquist TheoremChoices: a. equal to the lowest frequency of a signal b. equal to the highest frequency of a signal c. twice the bandwidth of a signal d. twice the highest frequency of a signal

ANSWER: d twice the highest frequency of a signalQUESTION:It is used in wireless applications in which stations must be able to share the medium without interception by an eavesdropper and without being subject to jamming from a malicious intruderChoices: a. modulation b. Multiple accessc. multiple access d. Spread spectrum

ANSWER: d. spread spectrumQUESTION:An error detection method which uses one’s complement arithmeticChoices: a. Checksum b. CRC c. Simple-parity check d. Two-dimensional parity check

ANSWER: a. ChecksumQUESTION:It is a connecting device between two internetworks that use different modelsCHOICES: a. Bridge b. Gateway c. Repeater d. router

ANSWER: b. gatewayQUESTION:It is an undesired shift or width change in digital bits of data due to circuitry action which causes bits to arrive at different timesChoices: a. alias b. impulsec. jitter d. parity

ANSWER: c. jitterQUESTION:In PCM system, it is the ratio of the maximum input voltage level to the smallest voltage level that can be quantized CHOICES: a. Dynamic range b. Figure of merit c. Quality factor d. Noise figure

ANSWER: a. Dynamic rangeQUESTION:A multiplexer combines four 100-kbps channels using a time slot of 2 bits, determine the frame duration.Choices: a. 20s b. 50s c. 100s d. 400s

ANSWER: a. 20sSOLUTION ( IF PROBLEM -SOLVING)The link carries 50,000 frames /secThe frame duration = 1/50,000 = 20s

QUESTION:Determine the Hamming distance for the codewords ( 10101, 11001)Choices: a. one b. two c. three d. five

ANSWER: b. twoSOLUTION ( IF PROBLEM -SOLVING)10101 XOR 11001 = 01100 ( presence of two 1)QUESTION:An address space is the total number of addresses used by the protocol, such as IPv4 and IPv6. What is the address space of IPv6?Choices: a. 232

b. 264

c. 296

d. 2128

ANSWER: d. 2128 QUESTION: It is a standard designed by ITU to allow telephones in the public telephone network to talk to computers/terminals connected to the internetChoices: a. H. 111 b. H.123 c. H.321 d. H. 323

ANSWER: d. H.323 QUESTION:A computer monitor has a resolution of 1200 by 1000 pixels. If each pixel uses 1024 colors, how many bits are needed to send the complete contents of a screen?Choices: a. 12 Gigabits b. 1. 2 Gigabits c. 120 Megabits d. 12 Megabits

ANSWER: d. 12 Megabits SOLUTION ( IF PROBLEM -SOLVING)1,200 times 1000 pixels x 10 bits = 12 Mb1024 colors requires 10 bits , 210 = 1024QUESTION:By how much should two antennas be separated for space diversity in the 11 GHz band? Choices: a. 5.5 m b. 7.5m c. 9.5m d. 11.5m

ANSWER: a. 5.5 mSOLUTION ( IF PROBLEM -SOLVING)

QUESTION:What is the phase velocity of a rectangular waveguide with a wall separation of 3 cm and a desired frequency of operation of 6 GHz?Choices: a. 3.45 x 108 m/s b. 4.35 x 108 m/s c. 4.53 x 108 m/s d. 5.43 x 108 m/s

ANSWER: d. 5.43 x 108 m/sSOLUTION ( IF PROBLEM -SOLVING)

QUESTION:A transmitter and a receiver is 45 km apart. Suppose that there is an obstacle midway between the transmitter and receiver. By how much must the path between the towers clear the obstacle in order to avoid diffraction at a frequency of 11 GHz?Choices: a. 17.52 m b. 10.51 m c. 8.76 m d. 7.52 m

ANSWER: b. 10.51 m SOLUTION ( IF PROBLEM -SOLVING)

QUESTION:How far from the transmitter could a signal be received if the transmitting and receiving antennas where 40 m and 20 m, respectively, above level terrain?Choices: a. 44.5 km b. 45.4 km c. 54.4 km d. None of the choices

ANSWER: a. 44.5 km SOLUTION ( IF PROBLEM -SOLVING)

QUESTION:A signal propagated in a waveguide has a full wave of electric intensity change between two further walls, and no component of the electric field in the direction of propagation. The mode is Choices: a. TE11 b. TE10 c. TM22 d. TE20

ANSWER: d. TE20QUESTION:An isolator has a forward loss of 0.7 dB and a return loss of 26 dB. A source provides 1 W to the isolator, and the load is resistive with an SWR of 3. How much power is dissipated in the load?Choices: a. 1 W b. 851 mW c. 750 mW d. 638 mW

ANSWER: d. 638 mWSOLUTION ( IF PROBLEM -SOLVING)

QUESTION:An isolator has a forward loss of 0.7 dB and a return loss of 26 dB. A source provides 1 W to the isolator, and the load is resistive with an SWR of 3. How much power returns to the source? Choices: a. 250 mW b. 350 µW c. 535 µW d. 690 µW

ANSWER: c. 535 µWSOLUTION ( IF PROBLEM -SOLVING)

QUESTION:It is a microwave device that allows RF energy to pass through in one direction with very little loss, but absorbs RF power in the opposite direction.Choices:a. multiplexer b. circulator c. isolator d. wave trap

ANSWER: c. isolator QUESTION:A metal wrapped around the parabolic antenna aperture to eliminate sidelobes interfering nearby stations is called Choices: a. radome b. shield c. shroud d. bass drum

ANSWER: c. shroud QUESTION:The wavelength of a wave in a waveguide _________.Choices: a. is greater than in free space b. depends only on the waveguide dimensions and the free space wavelengthc. is inversely proportional to the phase velocity d. is directly proportional to the group velocity

ANSWER: a. is greater than in free spaceQUESTION:The sensitivity of a radio receiver is given in terms of dBm. If the receiver is receiving 200 mW, what is the corresponding dBm of this signal?Choices: a. 46dBm b. -46 dBm c. 23 dBm d. -23 dBm

ANSWER: c. 23 dBmSOLUTION ( IF PROBLEM -SOLVING)dBm for 200 mW = 10 log (200mW/1mW) = 23 dBm

QUESTION:

An antenna with a noise temperature of 75 Kelvin is connected to a receiver input with a noise temperature of 300 K. Given the reference temperature T0 = 290 K, find the noise figure of the system. Choices: a. 0.97 dB b. 3.6 dB c. 6.02 dB d. 7.2 dB

ANSWER: b. 3.6 dBSOLUTION ( IF PROBLEM -SOLVING)The total noise temperature of the antenna and receiver is NTtot = 75+ 300 = 375.The noise temperature is given by:

where: NT – noise temp, NR = Noise ratioRearranging the above to find NR gives: NR = (375/290) +1 = 2.29The Noise figure is the decibel equivalent of the noise ratio, such that: NF = 10 log NR = 3.6 dB QUESTION:The modulation index of an AM radio station is 0.75. If the carrier power is 500W, what is the total transmitted power?Choices: a. 391 W b. 438 W c. 641 W d. 688 W

ANSWER: c. 641 WSOLUTION ( IF PROBLEM -SOLVING)The modulation index m is related to the total transmitted power Pt by:

where Pt = total transmitted power, Pc = carrier powerQUESTION:An FM transmitter system is using a 1MHz crystal oscillator to generate a very stable 108MHz final carrier frequency. The output of the crystal oscillator is fed to a x36 multiplier circuit then mixed with a 34.5 MHz signal. The sum output of the mixer is filtered out, while the difference is fed to another multiplier in order to generate the final carrier frequency. What is the multiplier value?Choices: a. 108 b. 3 c. 1.5 d. 72

ANSWER: d. 72SOLUTION ( IF PROBLEM -SOLVING)Basic Block Diagram of the FM carrier generator:1 MHz carrier > x 36 > Mixer > Multiplier > 108MHz carrierFirst Multiplier output: 1MHz x 36 = 36 MHzMixer output: 36MHz + 34.5 MHz = 70.5MHz (filtered output) 36MHz – 34.5 MHz = 1.5 MHz (difference fed to the next multiplier)Multiplier stage: Output = 108MHz Output = 1.5MHz x n N = 108/1.5 = 72QUESTION:A/an _______ is a range of frequency in which the upper frequency is double the lower frequency.Choices: a. bandwidth b. frequency doubler c. octave d. harmonics

ANSWER: c. octaveQUESTION:Determine the worst-case output S/N for a narrowband FM receiver with deviation maximum of 10 kHz and a maximum intelligence frequency of 3 kHz. The S/N input is 3:1.Choices: a. 10 b. 12 c. 14 d. 16

ANSWER: a. 10 SOLUTION ( IF PROBLEM -SOLVING)Φ = sin-1 (1/3) = 19.5 or 0.34 rad δ = Φ x fi = 0.34 x 3 kHz = 1 kHzThe S/N will be10 kHz/ 1 kHz = 10 QUESTION:A small variable capacitance in parallel with each section of ganged capacitor is called _______.Choices: a. trimmer b. converter c. padder d. autodyne

ANSWER: a. trimmer QUESTION: How many wavelengths long are required for a pair of conductors to be considered as a transmission line?Choices: a. ½ λ b. ¼ λ c. 1/10λ d. 5/8 λ

ANSWER: c. 1/10λ QUESTION: Determine the time taken for a signal to travel down a 10 m transmission line, if its velocity factor is 0.7.Choices: a. 23.33 ns b. 14.52ns c. 76.8 μs d. 47.6 ns

ANSWER: d. 47.6 nsSOLUTION ( IF PROBLEM -SOLVING)T= L/ (Vf x Vc)T= 10 m/ (0.7)(3x108 m/s)T= 47.6 nsQUESTION:

The maximum voltage standing wave of an RG-11/U foam coaxial cable is 52 V and its minimum voltage is 17 V. How many percent of the incident power is the reflected power?Choices: a. 51% b. 26% c. 3% d. 97%

ANSWER: b. 26% SOLUTION ( IF PROBLEM -SOLVING)Г 2 = Pr/PiГ = SWR-1 ; SWR = Vmax/ Vmin = 52/17 = 3.05 SWR+1Г = 3.05 – 1 = 0.51 3.05 +1 Thus : Г 2 = (0.51)2 = 0.26 The reflected power is 26 % of the incident powerQUESTION: At exactly one-quarter wavelength, the short-circuited transmission line behaves as a(an) ___________ circuit.Choices: a. inductive b. capacitive c. parallel-resonant d. series-resonant

ANSWER: c. parallel-resonant QUESTION: Determine the phase-shift represented by a 75 ns delay of a 4 MHz signal to a 75-ft cable with a dielectric constant of 2.3.Choices: a. 108 degrees b. 4.8 degrees c. 52 degrees d. 250 degrees

ANSWER: a. 108 degrees SOLUTION ( IF PROBLEM -SOLVING)Θ = 360 td / T T =1/f = 1 / 4MHz = 250 nsΘ = 360 (75) / 250 = 108 degreesQUESTION: Which of the following is a flat conductor separated by an insulating dielectric from a large ground plane that is usually one-quarter or one-half wavelength long?Choices: a. stripline b. microstrip c. twin-lead wire d. shielded-pair

ANSWER: b. microstrip QUESTION: One complete revolution around a Smith Chart represents _________ wavelengths.Choices: a. ½ λ b. ¼ λ c. 1 λ d. 2 λ

ANSWER: a. ½ λQUESTION: A mismatched transmission line is also referred to as a ___________ line.Choices: a. lossy b. lossless c. non-resonant d. resonant

ANSWER: d. resonantQUESTION: It is the ratio of the speed of propagation on a line to that of light in free-space.Choices: a. velocity factor b. refractive index c. dielectric constant d. standing-wave ratio

ANSWER: a. velocity factor QUESTION: Which of the following is the most widely used UTP cable that can carry baseband data at rates up to 100 Mbps at a range up to 100m?Choices: a. CAT 4 b. CAT 5 c. CAT 5e d. CAT 6

ANSWER: b. CAT 5 QUESTION: The modulated peak value of a signal is 125V and the unmodulated carrier value is 85V. What is the modulation index?Choices: a.0.47 b. 1.47 c. 0.68 d. 0.32

ANSWER: a.0.47 SOLUTION ( IF PROBLEM -SOLVING)m = Em/ Ec Emax = Ec + Em ; Em = Emax – Ec = 125 – 85 = 40 Vm = 40V/ 85V = 0.47QUESTION: The total transmitted power of an AM broadcast transmitter with a carrier power of 50kW when modulated 80 percent is:Choices:a. 62.5kW b. 66W c. 66kW d. 40kW

ANSWER: c. 66kWSOLUTION ( IF PROBLEM -SOLVING)Pt = Pc ( 1 + m2/2)Pt = 50,000 ( 1 + 0.82 /2)Pt = 66,000 WPt = 66kW

QUESTION:

One of the advantages of DSB is the savings of great deal of power. Which of the following is the reason why it is not widely used?Choices: a. the signal occupies a narrow bandwidth b. the signal has a low S/N c. the signal is weak at high frequencies d. the signal is difficult to demodulate

ANSWER: d. the signal is difficult to demodulateQUESTION: If the input in a transmitter is collector-modulated, the system is called a _______________________.Choices: a. low –level modulator b. high-level modulator c. differential- amplifier modulator d. lattice modulator

ANSWER: b. high-level modulator QUESTION: The input to an FM receiver has a S/N of 2.8. What is the frequency deviation caused by the noise if the modulating frequency is 1.5KHz and the permitted deviation is 4KHz? Choices:a. 1,460.8 Hz b. 547.8 Hz c. 2.67 Hz d. 4,107.3 Hz

ANSWER: b. 547.8 HzSOLUTION ( IF PROBLEM -SOLVING) = fm = sin -1 N/S = sin -1 1/2.8 = 0.3652 = (0.3652)(1.5KHz) = 547.8 HzQUESTION: What circuit is used to return the frequency response of a signal to its normal, “flat” level?Choices: a. pre-emphasis b. de-emphasis c. carrier-recovery d. frequency-multiplier

ANSWER: b. de-emphasis QUESTION: It is the most common means of overcoming the problems of quantizing error and noise.Choices: a. multiplexing b. companding c. amplifying d. anti-aliasing

ANSWER: b. companding QUESTION: ________________ means that the characteristics and performance of an antenna are the same whether the antenna is radiating or intercepting an electromagnetic signal.Choices: a. antenna reciprocity b. antenna polarization c. antenna grounding d. tower sway

ANSWER: a. antenna reciprocity QUESTION: Which of the following methods is used to lower the resonant frequency of a shortened vertical antenna?Choices: a. loading coil b. top hat loading c. drooping radials d. grounding

ANSWER: b. top hat loading QUESTION: Calculate the gain (relative to an isotropic) of a parabolic antenna that has a diameter of 3 m, an efficiency of 60% and operates at a frequency of 4 GHz. Choices: a. 39.8 dBi b. 41.94 dBi c. 37.66dBi d. 79.53 dBi

ANSWER: a. 39.8 dBiSOLUTION ( IF PROBLEM -SOLVING)G = 2 D2/ 2 = 3x108/ 4MHz = 0.075 mG = 0.62(3)2 0.0752G= 9474.8G = 10 log 9474.8G = 39.8 dBiQUESTION: It is a phenomenon caused by any support insulators used at the ends of the wire antenna.Choices: a. skin effect b. end effect c. faraday effect d. miller effect

ANSWER: b. end effect QUESTION: Combination of compression at the transmitter and expansion at the receiver of communications system.Choices: a. Decoding b. Companding c. compression d. Coding

ANSWER: b. CompandingQUESTION: A device launches or receives a wave in a transmission line or waveguide in one direction only.Choices: a. crossed-field tube b. directional coupler c. linear-beam tube d. slow-wave structure

ANSWER: b. directional couplerQUESTION: A type of linear-beam microwave tube that uses velocity modulation of the electron beamChoices: a. buncher b. Gunn device c. Bunching d. klystron

ANSWER: d. klystron

QUESTION:

A series of pulses in which the amplitude of each pulse represents the amplitude of the information signal at a given time.Choices: a. PAM b. PCM c. PDM d. PPM

ANSWER: a. PAMQUESTION: Combination of compression at the transmitter and expansion at the receiver of communications system.Choices: a. Decoding b. Companding c. compression d. Coding

ANSWER: b. CompandingQUESTION: A device launches or receives a wave in a transmission line or waveguide in one direction only.Choices: a. crossed-field tube b. directional coupler c. linear-beam tube d. slow-wave structure

ANSWER: b. directional couplerQUESTION:_______________ is used to position samples of the different message signals in non-overlapping time slots.Choices: a. FDM b. TDM c. CSMA-CD d. Hamming Code

ANSWER: b. TDMQUESTION:A ___________ is similar to a phasor diagram except that the entire phasor is not drawn.Choices: a. Product modulator b. constellation diagram c. truth table d. none of the above

ANSWER: b. constellation diagramQUESTION:It was the first fixed length character code.Choices: a. ASCII Code b. Baudot Code c. Morse Code d. EBCDIC Code

ANSWER: b. Baudot CodeQUESTION:It involves transmitting each character twice.Choices: a. Error Correction b. Redundancy c. Checksum d. Parity

ANSWER: b. RedundancyQUESTION:The __________ provides the mathematical justification for using a Gaussian Process as a model for a large number of different physical phenomena in which the random variable, at a particular instant of time, is the result of a large number of individual random events.Choices: a. Gaussian Theorem b. Central Limit Theorem c. Poisson Distribution d. Gaussian Distribution

ANSWER: b. Central Limit TheoremQUESTION: A set of communication facilities allowing direct access to 64kpbs data streams (or multiples of) for drop and insert. A form of cell relay, supports B-ISDN.Choices: a. synchronous digital hierarchy (SDH) b. Synchronization c. Asynchronous transfer mode (ATM) d. Asynchronous

ANSWER: c. Asynchronous transfer mode (ATM)QUESTION: A series of pulses, in which the timing of each pulse represents the ampltitude of the information signal at a given time.Choices: a. Pulse Width Modulation b. Pulse Code Modulationc. Pulse Duration Modulation d. Pulse Position Modulation

ANSWER: d. Pulse Position ModulationQUESTION: A line of sight radio link operating at a frequency of 6GHz has a separation of 40km between antennas. An obstacle in the path is located 10km form the transmitting antenna. By how much must the beam clear the obstacle?Choices: a.11.6m b. 11.6ft c. 10.6m d. 10.6ft

ANSWER: a.11.6mOLUTION ( IF PROBLEM -SOLVING)

R = 11.6mQUESTION: Variation in received field strength over time due to changes in propagation conditions.Choices: a. Repeater b. Fading c. Fresnel Zone d. Diversity

ANSWER: b. Fading

QUESTION:

The atomic weight of an element is approximately determined byChoices: a. the number of neutrons b. the number of protons c. the number of protons and neutrons d. the number of electrons

ANSWER: c. the number of protons and neutronsQUESTION:Of the following substances the most conductor isChoices: a. air b copper c. iron d. salt water

ANSWER: a. airQUESTION:The volt is the standard unit ofChoices: a. currrent b. charge c. electromotive force d. resistance

ANSWER: c. electromotive forceQUESTION:Which of the following antenna types is not designed for transmitting at 10 GhzChoices: a. horn antenna b dish antenna c. Zepp antenna d. helical antenna

ANSWER: c. Zepp antennaQUESTION:The type of radio wave responsible for long distance communications by multiple skips is the: Choices: a. Ground Wave b. Direct Wave c. Surface Wave d. Sky Wave

ANSWER: b. Direct WaveQUESTION:Line of sight communications is not a factor in which frequency range?Choices: a. VHF b. UHF c. HF d. Microwave

ANSWER: c. HFQUESTION:It refers to the rate of change of a signal on the transmission medium after encoding and modulation have occurred.Choices: Bit rate b. Baud c. bit d. Signalling element

ANSWER: b. BaudQUESTION:It was the first fixed-length character code developed for machines rather than people.Choices: a. ASCII code b. Baudot code c. EBCDIC code d. Code 39

ANSWER: b. Baudot CodeQUESTION:A receiver-transmitter station used to increase the communications range of VHF, UHF and microwave signals is called a(n):Choices: a. Transceiver b. Remitter c. Repeater d. Amplifier

ANSWER: c. RepeaterQUESTION:It represents the simplest whole number ratio of the various types of atoms in a compound. Choices: a. molecular formula b. chemical formula c. reactants d. empirical formula

ANSWER: d. empirical formulaQUESTION:It is a term that is often misunderstood and commonly confused with bit rate (bps) Choices: a. Bandwidth b ASK c. Baud d. FSK

ANSWER: c. BaudQUESTION:Defined as the optimum level of a test tone on a channel at same point in a communication system.Choices: a. transmission level point b. transmission level c. data level point d. error detecion

ANSWER: a. transmission level pointQUESTION:Duplicating each data unit for the purpose of detecting errors is a form of error detection called ___________.Choices: a. burst b. redundancy c. error correction d. error detection

ANSWER: b. redundancyQUESTION: Determine the wavelength of a 4 Ghz signal.Choices: a. 0.0075m b. 75m c. 750m d. 0.075m

ANSWER: d. 0.075mQUESTION: What is the device that converts energy from one form to another?Choices: a. transducer b. converter c. transceiver d. inverter

ANSWER: a. transducer

QUESTION:

It may be defined as any undesired voltages or currents that ultimately end up appearing in the receiver output.Choices: a. reflection b. Electrical noise c. interference d. loss

ANSWER: b. Electrical noiseQUESTION: The channel capacity of a 5 kHz bandwidth binary system is ____ bits/s. Assuming no noise.Choices: a. 1,000 b. 10,100 c. 10,000 d. 100,000

ANSWER: c. 10,000QUESTION: Microwaves are frequencies above _____ GHz.Choices: a. 2 b. 3 c. 1 d. None of the above

ANSWER: c.1QUESTION: The government agencies that regulates radio communications in the US is the ________.Choices: a. NCC b. FCC c. KBP d. PDCC

ANSWER: b. FCC (Federal Communications Commision)QUESTION: A wave guide acts a/an _______ filterChoices: a. high-pass b. low-pass c. Either a or b d. None of the above

ANSWER: a. High-passQUESTION: Coax is not used beyond frequencies of about ______ GHz.Choices: a. 6 b. 10 c. 4 d. 2

ANSWER: a. 6QUESTION: Data Communications refers to the transmission of ________.Choices: a. voice b. video c. Computer data d. All of the above

ANSWER: d. all of the aboveQUESTION: Determine the peak frequency deviation for a binary FSK signal with a mark frequency of 49 kHz, space frequency of 51kHz and an input bit rate of 2kbps.Choices: a. 1 kHz b. 1.5 kHz c. 2 kHz d. 2.5 kHz

ANSWER: a. 1 kHzSOLUTION ( IF PROBLEM -SOLVING)

QUESTION: It is often used to compare the performance of one digital modulation technique to another.Choices: a. bandwidth efficiency c. dynamic range b. baud rate d. Costas loop

ANSWER: a. bandwidth efficiencyQUESTION: It is the process of converting an infinite number of possibilities to a finite number of conditions.Choices: a. quantization c. aliasingb. sampling d. digitization

ANSWER: a. quantizationQUESTION: For a PCM system with a maximum analog frequency of 4kHz, determine the minimum sample rate.Choices: a. 8 kHz b. 9 kHz c. 10 kHz d. 11 kHz

ANSWER: a. 8 kHzSOLUTION ( IF PROBLEM-SOLVING)

QUESTION: It is another relatively simple form of redundancy error checking where each character has a numerical value assigned to it.Choices: a. Checksum c. Longitudinal redundancy checking b. Vertical redundancy checking d. Cyclic redundancy checking

ANSWER: a. Checksum

QUESTION:

It is a modulation and multiplexing technique that distributes the signal and its sidebands over a very wide bandwidth.Choices: a. Spread spectrum c. Frequency division multiplexingb. Phase shift keying d. Quadrature amplitude modulation

ANSWER: a. Spread spectrumQUESTION: The computers that hold shared files, programs and the network operating system. They also provide access to network resources to all the users of the network. Choices: a. Servers c. Transmission mediab. Clients d. Peripherals

ANSWER: a. ServersQUESTION: It is defined by the ITU-T as a service that provides transmission channels capable of supporting transmission rates greater than the primary data rate.Choices: a. Broadband ISDN c. LAN Topology b. Asynchronous Transfer Mode d. Ethernet

ANSWER: a. Broadband ISDNQUESTION: It is the only error-correction scheme that actually detects and corrects transmission errors when they are received without requiring a transmission..Choices: a. Forward Error Correction c. Code 39 b. Character Synchronization d. Line Control Scheme

ANSWER: a. Forward Error CorrectionQUESTION: This OSI Layer is responsible for network availability, data storage and processor capacity. It also determines the type of dialogue available.Choices: a. Session layer c. Data layer b. Network layer d. Transport layer

ANSWER: a. Session layerQUESTION: 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 energyfrom nearby objects.CHOICES: a. transmission loss b. atmospheric loss c. free space path loss d. spreading loss

ANSWER: c. free space path lossQUESTION: What do you call the accumulation of additional sounds such as wind, street noise, other voices that contribute to what the listener hear?CHOICES: a. natural sound b. ambience c. sound amplitude d. flutter sound

ANSWER: b. ambience QUESTION:It is a single transmission path from transmitter to receiver with line of sight range.CHOICES: a. diversity b. direct path c. jitter d. hop

ANSWER: d. hopQUESTION: It is defined by the average rate at which energy is carried out per unit area.CHOICES: a. Harmonics b. Intensity c. Frequency d. Interference

ANSWER: b. intensity QUESTION: What happens to the frequency of the wave and to its wavelength when a sound wave produced in one medium enters another medium with a different speed?CHOICES: a. the frequency of the wave and wavelength changes b. the frequency of the wave changes while the wavelength stays the same c. the frequency of the wave stays the same while the wavelength changes d. the frequency of the wave and wavelength remains the same

ANSWER: c. the frequency of the wave stays the same while the wavelength changes.

QUESTION: An interest rate of 10% compounded continuously is desired of an investment of P15,000. How many

years will be required to recover the capital with the desired interest if P2,500 is received each year?CHOICES: a. 3.579 years b. 5.973 years c. 9.375 years d. 7.953 years

ANSWER: c. 9.375 years

SOLUTION (IF PROBLEM SOLVING)A=Pert

15,000 = 15,000e0.10t-2500tt = 9.375 yearsQUESTION:What is the pH level of toilet soap?CHOICES: a. 14 b. 4 c. 10 d. 7

ANSWER: c.10QUESTION: The process of combining multiple audio signals into one track is called?CHOICES: a. audio mixing b. stereo panning c. stereo mixing d. audio signal processing

ANSWER: a. audio mixingQUESTION: The speed of sequence of musical notes is called?CHOICES: a. pitch b. tempo c. timbre d. musical instrument digital interface (MIDI)

ANSWER: b. tempoQUESTION: If the frequency of a sound is increased, what will happen to its pitch?CHOICES: a. decreases b. increases c. remains the same d. none of the above

ANSWER: b. increasesQUESTION:A type of microwave protection system where each working channel has a dedicated back up or spare channel.CHOICES: a. Frequency diversity b. Space diversity c. Hybrid diversity d. Hot Standby

ANSWER: d. Hot StandbyQUESTION:A method of nonspontaneous lysing (splitting) of a substance by the input of electrical energy, and is often used to decompose a compound into its elements.Choices: a. extraction b. electrolysis c.excitation d. fixation

ANSWER: b. electrolysisQUESTION: Also known as Pin 21 of the RS-232 interface on D connector, this connection allows signals to be transmitted from the DCE to the attached DTE whenever there is a high probability of an error in the received data due to the quality of the circuit falling below a predefined level.CHOICES: a. DCE transmitter signal element timing b. color quality selector c. signal quality detector d. DTE transmitter signal element timing

ANSWER: c. signal quality detectorQUESTION: It is the electrostatic forces of attraction between oppositely charged ions.CHOICES: a. ionic bonding b. covalent bonding c. metallic bonding d. multiple bonding

ANSWER: a. ionic bonding

QUESTION:______ which means that 2 or more bits in the data unit have changed.?CHOICES: a. singe bit error b. double bit error c. burst error d. none of the above

ANSWER: c. burst errorQUESTION: It is a four-wire Gigabit Ethernet implementation.CHOICES: a. 1000 Base-SX b. 1000 Base-LX c. 1000Base-T d. 1000 Base-CX

ANSWER: c. 1000 Base-TQUESTION:It is a digital process that allows several connections to share the high bandwidth of a link.CHOICES: a. TDM b. FDM c. WDM d. None of the above

ANSWER: a. TDMQUESTION:IEEE 802.11 is define in which MAC sublayer?CHOICES: a.NCF b.PCF c.DCF d. (b) and (c)

ANSWER: d. (b) and (c)QUESTION:It is the oldest microwave tube design which is commonly used in radar transmitters where they can generate peak power levels in the megawatt range.CHOICES: a. Klystron b. Magnetron c. Microstrip d. crossed field tube

ANSWER: b. MagnetronQUESTION:A modulation process wherein both frequence and phase remains constant while the amplitude changes.CHOICES: a. PSK b. ASK c. FSK d. QAM

ANSWER: b. ASKQUESTION:It is the most powerful redundancy checking technique which is based on binary division.CHOICES: a. cheksum b. parity check c. cyclic redundancy check d. two dimensional parity

ANSWER: c. cyclic redundancy checkQUESTION:What do you call the element with electrical properties between those of an insulator and a conductor?CHOICES: a. Semiconductor b. Conduclator c. Insuductor d. Medium conductor

ANSWER: a. SemiconductorQUESTION:It is the term applied to any method of extinguishing a debt, principal and interest, by a series of payments, usually at equal intervals.CHOICES: a. calculation of fixed charges b. amortization c. capacity costing d. repeatability assumption

ANSWER: b. amortizationQUESTION:In pulse-code modulation, it translates the quantized samples into digital code words.Choices: a. ADC b. DAC c. encoder d. decoder

ANSWER: c. encoder

QUESTION:It is an error detection technique in which a redundant bit is appended to every data unit so that the total number of 1s in the unit (including the parity bit) becomes even. Choices: a. vertical redundancy check b. longitudinal redundancy check c. cyclic redundancy check d. checksum

ANSWER: a. vertical redundancy check QUESTION:A local area network topology in which the individual terminal, microcomputers or workstations are connected directly to a central computer.Choices: a. Star b. Ring c. Bus d. Mesh

ANSWER: a. Star QUESTION:The only way to achieve high data rates with a narrowband channel is to increase the number of bits per symbol, the most reliable way to do this is to use a combination of amplitude and phase modulation known as _________.Choices: a. quadrature amplitude modulation b. phase shift keyingc. frequency shift keying d. frequency modulation

ANSWER: a. quadrature amplitude modulation QUESTION:Find the maximum dynamic range for a linear PCM system using 16-bit quantizing.Choices: a. 4.82 dB b. 25.84 dB c. 51.68 dB d. 98.08 dB

ANSWER: d. 98.08 dBSOLUTION ( IF PROBLEM -SOLVING)DR = 1.76 + 6.02m; dBDR = 1.76 + 6.02(16)DR = 98.08 dBQUESTION:Compute the baud rate for a 72000 bps 64-QAM signal.Choices: a. 12000 baud b. 1200 baud c. 120000 baud d. 12 baud

ANSWER: a. 12000 baud SOLUTION ( IF PROBLEM -SOLVING)A 64-QAM signal means that there are 6 bits per signal element since 26 = 64.Therefore, baud rate = 72000/6 baud rate = 12000 baudQUESTION:A telephone signal takes 2ms to reach its destination. Calculate the via net loss required for an acceptable amount of echo.Choices: a.0.6 dB b. 1 dB c. 0.4 dB d. 0.8 dB

ANSWER: d. 0.8 dBSOLUTION ( IF PROBLEM -SOLVING)VNL = 0.2t + 0.4dBVNL = 0.2 (2ms) + 0.4 dBVNL = 0.8 dBQUESTION:Telephone switch that connects only to other switches, and not to individual customers. Choices: a.central office b. toll station c. tandem office d. PSTN

ANSWER: c. tandem office QUESTION:It is a form of digital modulation similar to PSK except the digital information is contained in both amplitude and the phase of the transmitted carrier.Choices: a. FSK b. ASK c. QAM d.BPSK

ANSWER: c. QAM QUESTION:The most common circuit used for demodulating binary FSK signals.Choices: a. squarer b. PLL c. bandpass filter d.frequency divider

ANSWER: b. PLL QUESTION:We have an audio signal with a bandwidth of 4KHz.What is the bandwidth needed if we modulate the signal using AM? Ignore FCC regulations for now.CHOICES:4 KHz b. 8 GHz c. 8 KHz d. 4 GHz

ANSWER: c. 8 KHzSOLUTION (IF PROBLEM – SOLVING)BW = 2 x 4 KHz= 8 KHzQUESTION:We have an audio signal with a bandwidth of 4 MHz. what is the bandwidth if we modulate the signal using FM? Ignore FCC regulations.Choices: a. 8 b. 6 c. 36 d. 40

ANSWER: d. 40SOLUTION ( IF PROBLEM -SOLVING) An FM signal requires 10 times the bandwidth of the original signal. BW=10x4 = 40 MHz

QUESTION:For PCM system with the following parameters determine the minimum number of bits used.Maximum analog frequency= 4 khz, maximum decoded voltage=±2.55, Minimum dynamic range= 199.5 Choices: a. 7 b. 6 c. 8 d. 9

ANSWER: c. 8SOLUTION ( IF PROBLEM -SOLVING)

= 7.63 = 8QUESTION:A network topology in which data circulates from one computer to the next in sequence.Choices: a. ring b. star c. bus d. mesh

ANSWER: a. ringQUESTION:Find the maximum dynamic range for linear PCM system using 8-bit quantizingChoices: a. 2.01 dB b. 20.1 dB c. 49.92 dB d. 4.992 dB

ANSWER: c. 49.92 dBSOLUTION ( IF PROBLEM -SOLVING)DR = 1.76 + 6.02(m)DR = 1.76 + 6.02(8)QUESTION:What frequencies would be generated by a telephone using DTMF signalling, when the number 8 is pressed?Choices: a. 697 Hz and 1477 Hz b. 941 Hz and 1633 Hz c. 852 Hz and 1336 Hz d. 770 Hz and 1209 Hz

ANSWER: c. 852 Hz and 1336 HzQUESTION:It is a means of transmitting data by shifting the phase angle of the transmitted signal.Choices: a. FSK b. PSK c. ASK d. QAM

ANSWER: b. PSKQUESTION:The name given for a set of standards for communicating among computers in which the primary purpose is to serve as a structural guideline for exchanging information between computers, workstations and networks.Choices: a. OSI b. TCP/IP c. PDU d. LAN

ANSWER: a. OSIQUESTION:Any transmission system which conveys more than one signal simultaneously can experience this type of interference due to the reception of portions of a signal from one channel in another channel.Choices: a. Distortion b. Noise c. Crosstalk d. Echo

ANSWER: c. CrosstalkQUESTION:What type of digital modulation scheme uses two or more different output frequencies?Choices: a. PSK b. FSK c. QAM d. QPSK

ANSWER: b. FSKQUESTION:It is an error-correcting code used for correcting transmission errors in synchronous data streams. Choices: a. Hamming code b. Morse Code c. ASCII code d. Baudot code

ANSWER: a. Hamming CodeQUESTION:A suite of protocols that allows a wide variety of computers to share the same network.Choices: a. TCP/IP b. HTTP c. FTP d. SMTP

ANSWER: a. TCP/IPQUESTION:Noise that is primarily caused by lightning. Often called as Static Noise.Choices: a. external noise b. equipment noise c. atmospheric noise d. space noise

ANSWER: c. atmospheric noiseQUESTION:A modulation technique in which the frequency of the modulated signal varies with the amplitude of the modulating signalChoices: a. AM b. FM c. PM d. HM

ANSWER: a. AMQUESTION:Is a form of constant –amplitude angle modulation similar to standard frequency modulation except the modulating signal is a binary signal that varies between two discrete voltage levels rather than a continuously changing analog waveform.Choices: a. ASK b. FSK c. CP-FSK d. BPSK

ANSWER: b. FSK

QUESTION:The highest layer in the hierarchy and is analogous to the general manager of the network by providing access to the OSI environment.Choices: a. Application layer b. Presentation Layer c. Transport layer d. Session Layer

ANSWER: a. Application layerQUESTION:What is the equation for Hartley’s Law?Choices: a. I=ktB b. C=2Blog2M c. fa=fs-fm d. N=2^m

ANSWER: a. I=ktBQUESTION:Network topology wherein individual terminals, microcomputers and workstations are connected directly to a central computer. Choices: a. Mesh b. Bus c. Ring d. Star

ANSWER: d. StarQUESTION:The loss of data that occurs when two stations transmit at the same time on a networkChoices: a. multitasking b. cross-over c. collision d. traffic

ANSWER: c. collision QUESTION:A term used to describe a telephone instrument whose handset is on its cradle, ready to receive a ring signalChoices: a. On hook b. Off hook c. crosstalk d. sidetone

ANSWER: a. On hookQUESTION:The most commonly used digital modulation scheme.Choices: a. PCUM b. PPM c. PDM d. PCM

ANSWER: d. PCMQUESTION:Simple form of redundancy error checking where each character has a numerical value assigned to it. The characters within a message are combined together to produce an error checking character.Choices: a. CRC b. LRC c. Checksum d. VRC

ANSWER: c. ChecksumQUESTION:Is an eight-bit fixed length character set developed in 1962 by the International Business Machines Corporation.Choices: a. ASCII code b. Baudot Code c EBCDIC code d. Code 39

ANSWER: c. EBCDIC codeQUESTION:An attempt is made to transmit base band frequency of 30khz using a digital audio system with a sampling rate of 44.1khz. What audible frequency would result?Choices: a. 14.1KHz b. 74.1KHz c. 14.1MHz d. 7.05KHz

ANSWER: a. 14.1KHz SOLUTION ( IF PROBLEM -SOLVING)fa = fs – fm = 44.1KHz – 30KHz = 14.1 KHzQUESTION:Calculate the capacity of a telephone channel that has a S/N of 1023?Choices: a. 16,000 b/s b. 30,000 b/s c. 25,000b/s d. 3000 b/s

ANSWER: b. 30,000 b/sSOLUTION ( IF PROBLEM -SOLVING)The telephone channel has a bandwidth of about 3KHzC= BW log2 (1+ S/N) = 3 x 103 log2 (1+ 1023) =30000 b/sQUESTION:Designed to send characters of the message with the specified bit rate but without any fixed timing relationship from one character to the next. Choices: a. asynchronous b. synchronous c. error detection d. error corection

ANSWER: a. asynchronous QUESTION:Token Ring StandardChoices: a. 802.2 b. 802.3 c. 802.4 d. 802.5

ANSWER: d. 802.5QUESTION: Which of the following is not a reason why most half-wave antennas are mounted horizontally at low frequencies?Choices: a. physical construction is easier b. more cost-effectivec. mounting is easier d. support is easier

ANSWER: b. more cost-effective

QUESTION: The shape of the electromagnetic energy radiated from or received by an antenna is called theChoices: a. signal shape b. electromagnetic patternc. radiation pattern d. antenna pattern

ANSWER: c. radiation pattern QUESTION: Antennas that transmit an equal amount of energy in the horizontal direction are calledChoices: a. bi-directional b. unidirectionalc. omnidirectional d. unilateral

ANSWER: c. omnidirectionalQUESTION: The ability of an antenna to send or receive signals over a narrow horizontal directional range is referred to asChoices: a. focal factor b. permittivityc. directivity d. horizontal range

ANSWER: c. directivityQUESTION:A basic antenna connected to a transmission line plus one or more additional conductors that are not connected to the transmission line form aChoices: a. parasitic array b. bi-directional arrayc. half-wave dipole d. counterpoise

ANSWER: a. parasitic arrayQUESTION: An antenna made up of a driven element and one or more parasitic elements is generally referred to as aChoices: a. Hertz antenna b. Marconi antennac. collinear antenna d. Yagi antenna

ANSWER: d. Yagi antennaQUESTION: Which antennas usually consist of two or more half-wave dipoles mounted end to end?Choices: a. Hertz b. Marconic. collinear d. Yagi

ANSWER: c. collinearQUESTION: A stacked collinear antenna consisting of half-wave dipoles spaced from one another by one-half wavelengths is theChoices: a. broadside array b. end-fire arrayc. wide-bandwidth array d. parasitic array

ANSWER: a. broadside arrayQUESTION: When the characteristic impedance of the transmission line matches the output impedance of the transmitter and the impedance of the antenna itself,Choices: a. the SWR will be 10:1 b. the SWR will be 1:10c. minimum power transfer will take place d. maximum power transfer will take place

ANSWER: d. maximum power transfer will take placeQUESTION: A one-quarter wavelength of coaxial or balanced transmission line of a specific impedance connected between a load and a source in order to match impedances isChoices: a. a balun b. an autotransformerc. a Q section d. dummy load

ANSWER: c. a Q sectionQUESTION:It is the process of extracting a phase-coherent reference carrier from a receiver signal.Choices: a. Carrier Recovery b. Squaring Loop c. Costas Loop d. Remodulator

ANSWER: a. Carrier Recovery

QUESTION:It is a potential problem whenever two metallic conductors carrying different signals are located in close proximity to each other.Choices: a. Hybrid b. Noise c. Crosstalk d. Echo suppresors

ANSWER: c. CrosstalkQUESTION:What is the termed refer as the rapid degradation of output signal quality with channel induced errors?Choices: a threshold effect b intersymbol interference c. quantization d. saturation

ANSWER: a. threshold effectQUESTION:What was the first fixed-length character code developed for machines rather than for people?Choices: a ASCII code b EBCDIC code c. Code 39 d. Baudot code

ANSWER: d. Baudot codeQUESTION:A source whose output satisfies the condition of statistical independence among letters in the sequence is said to be_____.Choices: a. memoryless b. stationary c. entropy d. equivocation

ANSWER: a. memorylessQUESTION: Calculate the minimum data rate needed to transmit audio with sampling rate of 30 Khz and 14 bits per sample.Choices: a. 420 b/s b. 420 Kb/s c. 420 Mb/s d. 420 Gb/s

ANSWER: b. 420 Kb/sSOLUTION ( IF PROBLEM -SOLVING)D = fsm = 30 x 103 x 14 = 420 x 103 b/s = 420 Kb/sQUESTION: Handles error recovery, flow control (synchronization), and sequencing (which terminals are sending and which are receiving). It is considered the “media access control layer”.Choices: a. Transport Layer b. Session Layer c. Data Link Layer d. Application Layer

ANSWER: c. Data Link LayerQUESTION: A MAC protocol for LANs, with stations connected topologically or logically in a ring. Or the IEEE 802.5 LAN standard.Choices: a. Token Ring b. Token Bus c. Token d. Topology

ANSWER: a. Token RingQUESTION:A network topology where each device is connected to a centre point and all data is routed through that point.Choices: a. Star stop transmission b. Star bitsc. Star network d. Star wired ring network

ANSWER: c. Star network QUESTION:A lasers use organic dyes enclosed in a glass tube for an active medium, dye is circulated into the tube with a pump. A powerful pulse of light excites the organic dye.Choices: a. Solid Lasers b. Semiconductor Lasersc. Gas Lasers d. Liquid Lasers

ANSWER: d. Liquid LasersQUESTION:Codes that have a restriction on the number of consecutive 1s or 0s in a sequence.Choices: a. Fixed weight code b. Linear Block codesc. Systematic code d. Run length limited code

ANSWER: d. Run length limited codeQUESTION:Contains seven bytes (56 bits) of alternating 0s and 1s that alert the receiving system to the coming frame and enable it to synchronize its input timingChoices: a. padding b. preamble c. CRC d. signaling

ANSWER: b. preambleQUESTION:Every letter was encoded into fixed length of binary code words of length 5.Choices: a. Manchester Code b. Baudot Code c. Trellis Code d. Morse Code

ANSWER: b. Baudot CodeQUESTION:The composite signal that modulates the FM carrier. Choices: a. narrowband b.baseband c. sideband d. singleband

ANSWER: b. baseband

QUESTION:

It is a simple means of error detection. It involves the addition of one extra bit to the bits that encode a character.Choices: a. Parity b. Checksum c. Hamming code d. Cyclic redundancy check

ANSWER: a. parity QUESTION:A data compression scheme that uses fewer bits to represent more frequently occurring characters or bit patterns and more bits to represent those occur less frequently.Choices: a. Cyclic redundancy check b. Bit stuffing c. Huffman coding d. Bit overhead

ANSWER: c. Huffman coding QUESTION:Speed at which symbols are transmitted in a digital communication systems.Choices: a. Bit rate b. Baud rate c. Data rate d. Flow rate

ANSWER: b. Baud rate QUESTION:It is the process of converting an infinite number of possibilities to a finite number of conditions.Choices: a. Coding b. Sampling c. Companding d. Quantization

ANSWER: d. QuantizationQUESTION:It is the ratio of the largest possible magnitude to the smallest possible magnitude that can easily be decoded by the digital to analog converter in the receiver.Choices: a. Sampling rate b. Noise Ratio c. Dynamic Range d. Coding Efficiency

ANSWER: c. Dynamic RangeQUESTION:It is the institution that developed the ASCII (American Standard Code for Information Intertchange).Choices: a. ISO b. ANSI c. FCC d. IEEE

ANSWER: b. ANSIQUESTION:In early 1900s, he showed that any composite signal is a sum of a set of sine waves of different frequencies, phases and amplitudes.Choices: a. Henri Fourier b. Robert Fourier c. Jean-Baptiste Fourier d. Harry Nyquist

ANSWER: c. Jean-Baptiste FourierQUESTION:Find the binary equivalent of x8+x3+x+1.Choices: a. 100001011 b. 011110100 c. 010000101 d. 110000101

ANSWER: a. 100001011SOLUTION ( IF PROBLEM -SOLVING)x8+x7+x6+x5+x4+x3+x2+x+k 1 0 0 0 0 1 0 1 1QUESTION:Given a bandwidth of 6000 Hz for an ASK signal, what is the baud rate?Choices: a. 3000 Hz b. 2000 Hz c. 12000 Hz d. 6000 Hz

ANSWER: d. 6000 HzSOLUTION ( IF PROBLEM -SOLVING)baud rate = bandwidth6000 Hz = 6000 HzQUESTION:Compute the bit rate for a 2000 baud 16-QAM signal.Choices: a. 8000 bps b. 4000 bps c. 2000 bps d. 500 bps

ANSWER: a. 8000 bpsSOLUTION ( IF PROBLEM -SOLVING)bit rate = baud * 4 2000 * 4 = 8000 bpsQUESTION:It is an electronic device that is used for computer communications through telephone lines.Choices: a. hub b. Modem c. Router d. NIC

ANSWER: b. modemQUESTION:A telephone line has a bandwidth of 4.5 kHz and a signal-to-noise ratio of 40dB. A signal is transmitted down this line using a four level code. What is the maximum theoretical data rate?Choices: a. 59.795 kbps b. 18 kbps c. 78 kbps d. 41.795 kbps

ANSWER: b. 18 kbpsSOLUTION ( IF PROBLEM -SOLVING)C = 2Blog2M = 2(4.5x103)log2(4) = 18 kbpsS/N = antilog (40/10) = 10000C = Blog2(1+S/N) = (4.5x103)log2(1+10000) = 59.795 kbpsSince both results are maxima, we take the lesser of the two, 18 Kbps...

QUESTION:

Showed mathematically that it is posssible to reconstruct a band-limited analog signal from periodic samples, as long as the sampling rate is at least twice the frequency of the highest frequency component of the signal.Choices: a. Shannon-Hartley b. Claude E. Shannon c. Harry Nyquist d. R. Hartley

ANSWER: c. Harry NyquistQUESTION:Find the maximum dynamic range for a linear PCM system using 8-bit quantizing.Choices: a. 62.24 dB b. 49.92 dB c. 20.10 dB d. 15.78 dB

ANSWER: b. 49.92 dBSOLUTION ( IF PROBLEM -SOLVING)DR = 1.76 + 6.02m dB = 1.76 + 6.02(8) dB = 49.92 dBQUESTION:In operation, many modern codecs achieved compresion by first encoding the signals using a 12-bit linear PCM code, then converting the 12-bit linear code into an 8-bit compressed code by discarding some of the bits. This is a simple example of:Choices: a. Compression b. Differential PCM c. Vocoders d. Digital Signal Processing

ANSWER: d. Digital Signal ProcessingQUESTION:Sampling of an analog signal using a sample-and-hold circuit such that the sample has the same amplitude for its whole duration.Choices: a. Natural Sampling b. Flat-topped Sampling c. State Sampling d. Radom Sampling

ANSWER: b. Flat-topped SamplingQUESTION:The basic building block of the FDM hierarchy.Choices: a. Message Channel b. Group c. Multiplexer d. Small Group

ANSWER: a. Message ChannelQUESTION:The GSM radio system uses GMSK in a 200kHzchannel, with a channel data rate of 270.883 kbps. Calculate the frequency shift between mark and space.Choices: a. 135.4165kHz b. 100kHz c. 270.883kHz d. 200kHz

ANSWER: a. 135.4165kHSOLUTION ( IF PROBLEM -SOLVING)Fm-fs=0.5fb=0.5*270.833kHz=135.4165kHzQUESTION:For Ethernet system with a length of 2.5km on coaxial cable with a velocity factor of 0.66. What is the propagation delay?Choices: a. 12.6µs b. 8.33µs c. 1.27 µs d. 13.88 µs

ANSWER: a. 12.6µs SOLUTION ( IF PROBLEM -SOLVING)T=d/(VfC)=2.5km/(0.66*300000000m/s)=12.6 µsQUESTION:A signal at the input to a µ-Law compressor is positive, with its volatage one-half the maximum value. What proportion of the maximum output voltage is produced?Choices: a. 0.876Vo b. 0.678Vo c. 0.768Vo d. 0.867Vo

ANSWER: a. 0.876VoSOLUTION ( IF PROBLEM -SOLVING)Vo=Vo(ln(1+(255*0.5)))/ln(1+255)=0.876VoQUESTIONA telephone signal take 2ms to reach its destination. Calculate the via net loss required for an acceptable amount of echoChoices: a. 0.8dB b. 0.4004 dB c. 0.6 dB d. 2.6 dB

ANSWER: a. 0.8dB SOLUTION ( IF PROBLEM -SOLVING)VNL=0.2t+0.4=(0.2*2)+0.4=0.8QUESTION:Who invented the telegraph?Choices: a. Carl Friedrich c. Alexander Grahambell b. Samuel F.B Morse d. Emile Baudot

ANSWER: b. Samuel F.B MorseQUESTION:The simplest modulation technique, where a binary information signal modulates the amplitude of an analog carrier.Choices: a. Ampitude-Shift Keying c. Continous-Phase Frequency-Shift Keying b. Frequency-Shift Keying d. Phase-Shift Keying

ANSWER: a. Amplitude-Shift Keying

QUESTION:

Is the lowest Open System Interconnection hierarchy and is responsible for the actual propagation of unstructured data bits (1s and 0s) through a transmission medium.Choices: a. Physical Layer b. Data Link Layer c. Network Layer d. Transport Layer

ANSWER: a. Physical LayerQUESTION: Error-correction scheme that actually detect and corrects transmission errors when they are received without requiring a retransmission.Choices: a. Forward error correction b. Hamming code c. Retransmission d. CRC

ANSWER: a. Forward Error CorrectionQUESTION: It allows the overall complexity of the system to be broken down into individual function –layers- that operate essentially by themselves.Choices: a. Data Rate b. Transparency c. Physical Layer d.Format

ANSWER: b. TransparencyQUESTION:This are very useful pictorial representations that clearly show the protocol operations such as words or convetional drawings.Choices: a. State Transition Diagram b. Flow Chart Diagram c. Block Diagram d. Circuit Diagram

ANSWER: a. State Transition DiagramQUESTION:Pair of wires that connects the central office to the users phoneChoices: a . trunk b. local loop c. Telephone wire d. Network nodes

ANSWER: b. Local loopQUESTION:How long does it take to dial the number 784-3745 using pulse dialing with .5s inter digit time?Choices: a. 6.5s b. 7.2s c. 6.8s d. 12.5s

ANSWER: c. 6.8sSOLUTION ( IF PROBLEM -SOLVING)0.7 + 0.8 + 0.4 + 0.3 + 0.7 + 0.4 + 0.5 (6x0.5) = 6.8sQUESTION:Network that connects users who are in the same general locationChoices: a. WAN b. Star Tropology c. LAN d. Bus Tropology

ANSWER: c. LANQUESTION:In operation, many modern codecs achieved compresion by first encoding the signals using a 12-bit linear PCM code, then converting the 12-bit linear code into an 8-bit compressed code by discarding some of the bits. This is a simple example of:Choices: a. Compression b. Differential PCM c. Vocoders d. Digital Signal Processing

ANSWER: d. Digital Signal ProcessingQUESTION:A balanced modulator that will used in conjuction with a microwave generator, power amplifier, and band-pass filter, up-converts the IF carrier to an RF carrier and amplifies the RF to the desired output power.Choices: a. IF/RF modulator b. Transmit Modulator c. Recieved Modulator d. Equalizer

ANSWER: b. Transmit ModulatorQUESTION:The loss of data that occurs when two stations transmit at the same time on a networkChoices: a. multitasking b. cross-over c. collision d. traffic

ANSWER: c. collisionQUESTION:We have an audio signal with a bandwidth of 5 HHz. What is the bandwidth modulate the signal using FM? Ignore FCC regulation.CHOICES:a.50 MHz b. 40MHz c. 30 MHz d. 20MHz

ANSWER: a. 50 MHzSOLUTION (IF PROBLEM – SOLVING)BW= 10 x 5MHz = 50MHZQUESTION: Used to established a point to point connection across a network.Choices: a. ARP b.FTP c.TCP d.UDP

ANSWER: c. TCPQUESTION: An attempt is made to transmit a baseband frequency of 25kHz using digital audio system with a sampling rate of 44.1 kHz. What audible frequency would result?Choices: a. 39.1kHz b.19.1kHZ c.29.1kHz d.14.1kHz

ANSWER: b. 19.1kHzSOLUTION ( IF PROBLEM -SOLVING) fa = fs - fm = 44.1kHz – 25kHz = 19.1kHzQUESTION:

Defines the rules of the conversation the message passing among the network usersChoices: a. network protocol b. Internet protocol c. Data d. Information protocol

ANSWER: a. network protocolQUESTION:Responsible for providing signals to the loop sensing activity and sending phone signals at the end of the loopChoices: a. SLIC b. Interface card c. SCLIC d. Network card

ANSWER: a. SLICQUESTION:The typical amount of voltage in dc use in the battery of the central office with respect to groundChoices: a. -48 b.+72 c. +48 d. -72

ANSWER: a. -48QUESTION:A network that is composed of a smaller lan that are closely link. It is needed for areas spread out geographicallyChoices: a. MAN B. Network tropology c. WAN d. Linking system

ANSWER: c. WANQUESTION:How many central office allotted for each exchange?Choices: a.2 b. 1 c.3 d. 5

ANSWER: b. 1QUESTION:It is a method of switching that provides a separate physical path for each symbolCHOICES:a. circuit switching b. packet switching c. space switching d. time switching

ANSWER: c. space switchingQUESTION:The central office detects a request for service from a telephone by:CHOICES:a. a flow of loop current b. no loop current c. a ringing signal d. dial pulses

ANSWER: a. a flow of loop currentQUESTION:The OSI Layer responsible for data tracking as it moves through a network. It controls and ensures the end – to – end integrity of the data message propagated through the network between two devices.CHOICES:a. Application b. Transport c. Physical d. Session

ANSWER: b. TransportQUESTION:It is used on long – distance circuits, in an effort to overcome echoes caused by circuit imbalances.CHOICES:a. Echo Suppresors b. Echo Silencer c. Echo Remover d. Echo Balancer

ANSWER: a. Echo SuppresorsQUESTION: A dipole antenna has a radiation resistance of 67 ohms and a loss resistance of 5 ohms, measured at the feedpoint. Calculate the efficiency.Choices: a. 90% b. 91%c. 92% d. 93%

ANSWER: d. 93%SOLUTION:Efficiency = Rr / Rt = 67 / (67 + 5) = 93%QUESTION: Two antennas have gains of 5.3 dBi and 4.5 dBd, respectively. Which has a greater gain?Choices: a. The first antenna has a higher gain. b. The second antenna has a higher gain.c. Both antennas have the same gain d. Cannot be determined

ANSWER: b. The second antenna has a higher gain.QUESTION: A half-wave dipole is sometimes called:Choices: a. Marconi antenna b. Yagi antennac. Hertz antenna d. none of the choices

ANSWER: c. Hertz antennaQUESTION: An antenna's beamwidth is measuredChoices: a. from +90° to –90° b. between half-power pointsc. from front to back d. between the minor side-lobes

ANSWER: b. between half-power points

QUESTION:

"Ground Effects" refers to the effects on an antenna's radiation pattern caused byChoices: a. radio signals reflecting off the ground b. buildings and other structures on the groundc. fading d. faulty connection of the feed cable ground

ANSWER: a. radio signals reflecting off the groundQUESTION: An antenna can be matched to a feed line usingChoices: a. a shorted stub b. an LC networkc. a loading coil d. all of the choices

ANSWER: d. all of the choicesQUESTION: As the length of a "long-wire" antenna is increasedChoices: a. the number of lobes increases b. efficiency decreasesc. the number of nodes decreases d. none of the above

ANSWER: a. the number of lobes increasesQUESTION: LPDA stands forChoices: a. Low-Power Dipole Array b. Log-Periodic Dipole Arrayc. Low-Power Directed Array d. Log Power Dipole Array

ANSWER: b. Log-Periodic Dipole ArrayQUESTION: Field strength at a distance from an antenna is measured withChoices: a. a slotted line b. an EIRP meterc. a dipole d. a field-strength meter

ANSWER: d. a field-strength meterQUESTION: A receiving antenna with a built-in preamplifierChoices: a. active antenna b. passive antennac. coil d. LC antenna

ANSWER: a. active antenna