Microwave signals are used in satellite communication

Q=QUESTION question_description question_explanation question_type question_difficulty

A=ANSWER answer_description answer_explanation answer_isright answer_position

Q Microwave signals are used in satellite communication M 1

A They have ability to penetrate ionosphere 1 1

A They easely available 0 2

A Low cost 0 3

A Low bandwidth 0 4

Q V band is used for M 1

A terrestrial communication 0 1

A Intersatellite communication 1 2

A earth station communication 0 3

A optical communication 0 4

Q Orbit is defined as M 1

A Load carried by satellite 0 1

A it a communication path of satellite 0 2

A it a communication path of earth station 0 3

A Satellites move in a path around the Earth. 1 4

Q The orbit is a combination of the M 1

A Green patch 0 1

A satellite's velocity andforce of the Earth's gravitational pull on 1 2

A hight of satellite 0 3

A Application of satellite 0 4

Q LEO orbits satellite applications requires M 1

A less number of satellites then MEO 0 1

A More number of satellite then MEO 1 2

A Equal number of satellite 0 3

A Three satellites 0 4

Q “VAN ALLEN BELT” is availability between M 1

A from 2000 to 10000 Km 1 1

A from 500 to 1000 Km 0 2

A from 100 to 1000 Km 0 3

A from 8000 to 10000 Km 0 4

Q PSLV is used M 1

A to place LEO satellites 0 1

Module 1



A to place satellite in polar orbit 1 2

A to place MEO satellites 0 3

A to place GEO satellites 0 4

Q Advantage of high inclination is M 1

A Noise due to earth and RF user are more 0 1

A launching is easy 0 2

A low cost for launching 0 3

A Noise due to earth and RF user are less 1 4

Q Disadvantage of high inclination M 1

A more time for communication 0 1

A Periodic hand over of traffic from one to other satellite 1 2

A less coverage area 0 3

A difficult to trace the satellite 0 4

Q Sub satellite path is M 1

A the path generated by earth station 0 1

A the path traced out on the earth’s surface directly below the 1 2

A the path generated by satellite in the space 0 3

A the path generated by satellite antenna to transmit command 0 4

Q Station keeping means M 1

A The process of firing the rockets under ground control to 1 1

A keeping telephone station open for 24 hours 0 2

A Keeping earth station open 24 hours 0 3

A keeping satellite operating 24 hours 0 4

Q Geostationary satellite has an arc of visibility which called M 1

A Arc of operation 0 1

A foot print 1 2

A operating path 0 3

A limiting area 0 4

Q Earth Eclipse of satellite being M 1

A 23 days before spring and end 23 days after spring 0 1

A 20 days before equinox and end 20 days after equinox 0 2





Q The disadvantage of eclipse is M 1

A it reduce the satellite communication 0 1

A it reduce the satellite life 1 2

A it reduce the visibility of satellite 0 3

A it reduce cost of communication 0 4

Q Maximum sun transit outage time is M 1

A 2min 0 1

A 10 min 1 2

A 5 min 0 3

A 8 min 0 4

Q Sun transit outage occurs for M 1

A 6 days around the equinoxe. 1 1

A 3 days around the equinoxe 0 2



Q A Hohmann transfer method of satellite launching is M 1

A causes delay in the launching satellite 0 1

A fuel efficient method 1 2

A increases launching cast 0 3

A increase satellite life 0 4

Q The Augmented Satellite Launch Vehicle (ASLV) Programme M 1

A 100 Kg 0 1

A 20 Kg 0 2

A 200 Kg 0 3

A 150 kg 1 4Q world's most reliable launch vehicles is M 1

A GSLV 0 1

A PSLV 1 2

A ASLV 0 3

A ELV 0 4

Q Commonly used polarization in satellite communication is M 1

A Square polarization 0 1

A Circular polarization 1 2



A Elliptical polarization 0 3

A rectangular polarization 0 4

Q Cross Polarization Discrimination is M 1

A the ratio of Co-polar component with Cross-polar component 1 1

A the ratio of Cross-polar component with Co-polar component 0 2

A the ratio of Co-polar component with Co-polar component 0 3

A the ratio of Cross-polar component with Cross-polar 0 4

Q Satellite in space should have M 1

A high reliability 0 1

A very high reliability 1 2

A less reliability 0 3

A very less reliability 0 4

Q Bathtub curve is for M 1

A reliability failure 1 1

A Power failure 0 2

A Transponder 0 3

A Radiation 0 4

Q Most of the electronic equipment have probability of failure M 1

A is higher at the beginning of life 1 1

A is lower at the beginning of life 0 2

A is lower at the end of life 0 3

A is higher during night 0 4

Q The spin stabilization is for M 1

A Thermal control 0 1

A transponder control 0 2

A Power control 0 3

A Attitude control 1 4

Q In three axes(RPY),Yaw axes is directed towards M 1

A Earth centre 1 1

A Orbital plane 0 2

A sun centre 0 3

A moon centre 0 4

Module 2



Q The north-south station keeping tolerances for C band is M 1

A 0.1 degree 1 1

A 0.05 degree 0 2

A 0.2 degree 0 3

A 0.5 degree 0 4

Q The first stage in the receiver is M 1

A Power amplifier 0 1

A LNA 1 2

A mixer 0 3

A photo diode 0 4

Q The transmit and receive signals are separated in device is M 1

A duplexer 1 1

A Power amplifier 0 2

A LNA 0 3

A mixer 0 4

Q The Telemetry subsystem transmit information M 1

A about the satellite to the earth station 1 1

A about the earth to the satellite station 0 2

A about the satellite to the another satellite 0 3

A about the earth station to the other earth station 0 4

Q Satellite equipment should operate in M 1

A high temperature 0 1

A low temperature 0 2

A stable temperature 1 3

A very low temperature 0 4

Q The north-south station keeping tolerances for Ku band is M 1

A 0.1 degree 0 1

A 0.05 degree 1 2

A 0.2 degree 0 3

A 0.5 degree 0 4

Q The primary electrical power for operating the electronics M 1

A Hydrogen gas 0 1

A Battery 0 2



A Wind 0 3

A Solar cells 1 4

Q During eclipse_______ are used in satellite M 1

A Solar cells 0 1

A Storage battries 1 2

A Power amplifers 0 3

A Hydrogen gas 0 4

Q For transmitting an analog voice signal, the following modulator may be used at the earth stationM 1

A Wideband FM modulation 0 1

A Narrowband FM modulator 1 2

A BPSK modulator 0 3

A QPSK modulator 0 4

Q Down convertor is used to M 1

A Convert Downlink frequency into uplink frequency 0 1

A Convert High frequency on receiver side into an IF 1 2

A Convert analog signal into digital signal 0 3

A Convert digital signal into analog signal 0 4

Q Loss in the signal due to depolarization can be M 1

A Compensated with increasing the signal power 0 1

A Mitigated with diversity reception 0 2

A Compensated by increasing the beam width 1 3

A Eliminated by changing the frequency 0 4

Q Farady rotation M 1

A Does not affect vertically polarized waves 0 1

A Does not affect horizontally polarized and vertically polarized waves 0 2

A Does not affect circularly polarized waves 1 3

A Does not affect horizontally polarized waves 0 4

Q In Large earth station, the reliability is improved by providing_________in all the critical subsystems, which are prone to ____ M 1

A Redundancy, failure 1 1

A Band pass filter, Failure 0 2

A More EIRP, Failure 0 3

A Less EIRP, Failure 0 4

Module 3



Q The probability of failure is _____ for subsystem employing active device. M 1

A High 1 1

A Low 0 2

A Medium 0 3

A zero 0 4

Q Which is not a part of Large Earth station M 1

A LNA 0 1

A Up/Down Convertor 0 2

A Modulator/Demodulator 0 3

A Transponder 1 4

Q Television transmission is an example of which type of transmission? M 1

A Simplex 1 1

A Half Duplex 0 2

A Full Duplex 0 3

A Duplex 0 4

Q Which part of the transmitter subsystem modulates the baseband signal? M 1

A Antenna 0 1

A Up converter 1 2

A Power amplifiers 0 3

A Mixer 0 4

Q In RF tuning, _________ provides the final up conversion to the microwave frequency?M 1

A Fixed-frequency local oscillator 0 1

A RF frequency synthesizer 1 2

A Quartz oscillator 0 3

A Magnetic oscillator 0 4

Q When individual up converters are used to modulate a channel, what is used to combine them into final signal?M 1

A Microwave combiner 1 1

A Multiplexer 0 2

A Mixer 0 3

A Amplifier 0 4

Q Which of the following amplifiers is used in the transmitter substation? M 1

A RF amplifiers 0 1

A Buffer amplifiers 0 2



A Klystron amplifier 1 3

A Operational amplifiers 0 4

Q Which of the following are common baseband signals transmitted from the earth ground station?M 1

A Navigational data, computer data, video 0 1

A Computer data, navigational data, voice 0 2

A Voice, video, computer data 1 3

A Computer data 0 4

Q What type of satellite TV service uses compressed data transmission to beam signals directly to every home?M 1

A Direct broadcast satellite 1 1

A Mobile satellite service 0 2

A Broadcasting satellite service 0 3

A Fixed satellite service 0 4

Q What device is used to prevent power from the transmitter from going to the receiver side?M 1

A Multiplexer 0 1

A Duplexer 1 2

A Multivibrator 0 3

A Filter 0 4

Q Te=? M 1

A (F-1)To 1 1

A (F+1)To 0 2

A (To-1)F 0 3

A (To+1)F 0 4

Q Choose the correct equation of losses for clear M 1

A Losses=[FSL]+[RFL] 0 1

A Losses=[FSL]+[RFL]+[AML]+[AA]+[PL] 1 2

A Losses=[FSL]+[AML]+[AA]+[PL] 0 3

A Losses=[FSL]+[AML]-[AA]-[PL] 0 4

Q What is noise power spectral density? M 1

A N0 = PN/BN =KTNRB0 joules 0 1

A N0 = BN/PN = 4KTNBR 0 2

A N0 = BN/PN =KTNB0 joules 0 3

A N0 = PN/BN=KTN joules 1 4

Module 4



Q [EIRP]=? M 1

A [PS]+[G]dBW 1 1

A [PS][G]dBW 0 2

A [PS]-[G]dBW 0 3

A [PS]/[G]dBW 0 4

Q The off-axis loss is a major contributor for which loss? M 1

A FSL 0 1

A AML 1 2

A FL 0 3

A RFL 0 4

Q [C/N]=? M 1

A [PR]+[PN] 0 1

A [PR]/[PN] 0 2

A [PR]-[PN] 1 3

A [PR][PN] 0 4

Q [PHPA]=? M 1

A [EIRP]+[GT]+[TFL] 0 1

A [EIRP]-[GT]-[TFL] 0 2

A [EIRP]-[GT]+[TFL] 1 3

A [EIRP]+[GT]-[TFL] 0 4

Q Antenna Misalignment Losses [AML] include M 1

A polarization and atmospheric losses 0 1

A pointing and polarization losses 1 2

A dispersion and attenuation losses 0 3

A feeder and scattering losses 0 4

Q PN=? M 1

A kTNBNRG 0 1

A 3kRTNBN 0 2

A 3kRTNG 0 3

A kTNBN 1 4

Q In satellite communication, highly directional antennas are M 1

A direct the spot beam to a particular region of space on 1 1

A strengthen the beam to overcome the cosmic noise 0 2



A make corrections in change of polarisation of the beam 0 3

A select a particular channel in transmission and reception 0 4

Q The circuit that provides channelization in a transponder is M 1

A Mixer 0 1

A Local oscillator 0 2

A Bandpass filter 1 3

A HPA 0 4

Q Which one of the following statement is correct? M 1

A Satellite spacing is not affected by the bandwidth of the 0 1

A Beamwidth is independent of antenna size and frequency 0 2

A The width of a beam in space is inversely proportional to 1 3

A Use of high-frequency bands permits less number of 0 4

Q Space communication links are being increasingly moved M 1

A offers a much wider available bandwidth 1 1

A does not suffer from atmospheric at tenuation 0 2

A permits the use of smaller antenna 0 3

A does not suffer from rain attenuation 0 4

Q Which of the following statement regarding link loss for a M 1

A For fixed antenna, it is inversely proportional to f2 0 1

A For fixed frequency, it is inversely proportional to the 0 2

A For a given satellite operating at a given frequency, it is 0 3

A Loss in down-link is negligible as compared to that in 1 4

Q Why are techniques like frequency reuse and spatial M 1

A Reduce traffic load 1 1

A More gain 0 2

A High speed 0 3

A Error detection 0 4

Q …………. is a measure of the fraction of frame time M 1

A Preamble 0 1

A Guard time 0 2

A Frame efficiency 1 3

A Decoding quenching 0 4

Module 5



Q The most effective anti-jamming technique is ………. M 1

A Frequency hopping 0 1

A Spread-spectrum modulation 1 2

A Key leverage 0 3

A Once-only key 0 4

Q For satellite transmission, analog signals may be M 1

A Modem 0 1

A Transponder 0 2

A Codec 1 3

A Compandor 0 4

Q A form of CDMA where a digital code is used to M 1

A Spread Spectrum 0 1

A Frequency Hopping 1 2

A Store and Forward 0 3

A SPADE 0 4

Q The satellite frequency reuse method which sends M 1

A Multiple coverage areas 0 1

A Dual polarization 1 2

A Spatial separation 0 3

A Spread spectrum 0 4

Q The satellite multiple access technique which uses M 1

A FDMA 0 1

A TDMA 0 2

A CDMA 1 3

A DAMA 0 4

Q A method of multiple accessing where a given RF M 1

A CDMA 0 1

A ANIK-D 0 2

A TDMA 0 3

A FDMA 1 4

Q How can multiple earth stations share a satellite on M 1

A Frequency reuse 1 1

A Multiplexing 0 2



A Mixing 0 3

A Frequency hopping 0 4

Q The access scheme used by GPS M 1

A FDMA 0 1

A OFDMA 0 2

A TDMA 0 3

A CDMA 1 4

Q It implies that more than one user has an access to M 1

A Co-channel interference 0 1

A Satellite multi-accessing 1 2

A Frequency reuse 0 3

A Diversity 0 4

Q Integrating antennas and Solar cells on satellite can: M 1

A Increase the gain of the antenna 0 1

A Increase the power obtained on satellite 0 2

A Increase the cost of satellite 0 3

A Reduce the mass and volume of satellite 1 4

Q Why Satellite – based telemedicine system is useful? M 1

A It provides health care service to large population in big cities at low cost 0 1

A It provides access to specialist doctors for the population in rural and remote locations 1 2

A It can provide specially education to the doctors in universities 0 3

A It can motivate the medical specialist to work in rural areas 0 4

Q After it is switched on, the minimum time taken by a GPS receiver to compute its position is:M 1

A 1 min 0 1

A 4 min 0 2

A 10 min 0 3

A 12.5 min 1 4

Q In a DTH system: M 1

A The receiver can directly receive signals from any satellite 0 1

A The receiver can receive signals in ku-band or c-band using TVRO terminal 1 2

A The user terminal is capable of transmitting low rate data such as internet 0 3

A The receiver has a large antenna to directly receive signals in L-band 0 4

Module 6



Q DVB-S standard employs M 1

A BPSK modulation and MPEG-1 coder 0 1

A QPSK modulation, BCH encoder and MPEG-2 coder 0 2

A QPSK modulation, Concatenated coder and MPEG-2 coder 1 3

A QAM modulator, FEC coder and MPEG-2 coder 0 4

Q Geostationary satellite – based DAB systems are usually supported by ground-based FM rebroadcast systems because:M 1

A FM provides higher quality to users 0 1

A FM receivers are already used 0 2

A FM receivers are inexpensive 0 3

A The signal quality is poor to be received directly by receivers in low elevation angles 1 4

Q Inmarsat-5 series satellites M 1

A Have global beams to serve large areas 0 1

A Have spot beams providing high power to user terminals 1 2

A Operate in L-band to communicate with mobile users 0 3

A Providing only voice service at low rates 0 4

Q The GPS data are transmitted at: M 1

A 50b/s 1 1

A 37.5 kb/s 0 2

A 1.023Mb/s 0 3

A 10.23 Mb/s 0 4

Q In the GPS system , the Master control Stations communicate with the GPS satellites through the ground stations in:M 1

A L-band 0 1

A S-band 1 2

A C- band 0 3

A Ku-band 0 4

Q An aided GPS has the following advantage: M 1

A It can compute the position with less than four satellites 0 1

A It can provide better accuracy in the position 0 2

A It can speed up the position calculation 1 3

A It can work only with internet 0 4

Q Small satellites are placed in M 1

A Polar orbits 0 1

A GEO 0 2



A MEO 0 3

A LEO 1 4

Q Aircraft-based launching can be used for launching M 1

A Small satellites in geostationary orbit 0 1

A Microsatellites in LEO 1 2

A Large satellites in LEO 0 3

A Nanosatellites in LEO 0 4

Q Satellite refueling increases the M 1

A Weight of the satellite 0 1

A Velocity of the satellite 0 2

A Life of the satellite 1 3

A Accuracy of the satellite 0 4

Q Satellite-based distance education provides M 1

A Both regional and national coverage 1 1

A Regional coverage with different programs for each region 0 2

A Only national coverage with a single program 0 3

A Only national coverage with a different program 0 4

Q An IRD box contains electronics for: M 1

A Down converting the signal received from a satellite to L-band 0 1

A Low noise amplification and demodulation 0 2

A IF demodulation and MPEG decoder 1 3

A High frequency amplification and demodulation 0 4

Q HDTV signal has: M 1

A 5 times more BW compared to SDTV 1 1




Q The major design objective in DVB-S2 was to: M 1

A Maintain compatibility with DVB-S standard 0 1

A Enable receiving MPEG-2 video at lower cost 0 2

A Enhance the performance, reduce the Complexity and cost of receiver 1 3

A Design a receiver that can receive a signal with fixed modulation and coding 0 4

Q A low noise block converter: M 1



A Is an indoor unit placed in the home to demodulate and decode satellite TV signals 0 1

A Is an outdoor unit placed at the antenna feed to amplify received signal and convert to L-band 1 2

A Has a BW of 1 TV signal 0 3

A Converts Ku-band signal to 70 MHz IF and demodulates digital TV signals 0 4

Microwave signals are used in satellite communication

Documents

Transcript of Microwave signals are used in satellite communication