MCQOPTIONS
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MCQOPTIONS
This section includes 149 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
A satellite signal transmitted from a satellite transponder to earth’s station. |
| A. | Uplink |
| B. | Downlink |
| C. | Terrestrial |
| D. | Earthbound |
| Answer» C. Terrestrial | |
| 52. |
Most mobile satellite array uses ___________ in transforming 50 to 150 Ω impedance. |
| A. | Stub |
| B. | Balun |
| C. | Quarter-wavelength transformer |
| D. | Microstrip tapers |
| Answer» D. Microstrip tapers | |
| 53. |
A mobile satellite array has usually how many elements? |
| A. | 6 |
| B. | 88 |
| C. | 12 |
| D. | 14 |
| Answer» E. | |
| 54. |
AsiaSat I covers how many countries in Asia? |
| A. | 38 |
| B. | 10 |
| C. | 28 |
| D. | 15 |
| Answer» B. 10 | |
| 55. |
The owner of AsiaSat 2 is |
| A. | Asia Satellite Telecommunications Company (ASTC) |
| B. | Japan Satellite System (JSAT) |
| C. | China Great Wall Industry Corporation |
| D. | Singapore Satellite Commision |
| Answer» D. Singapore Satellite Commision | |
| 56. |
Earth station uses what type of antenna |
| A. | Despun antenna |
| B. | Helical antenna |
| C. | Toroidal antenna |
| D. | Cassegrain antenna |
| Answer» E. | |
| 57. |
A satellite beam that covers almost 42.4% of the earths surface. |
| A. | Zone beam |
| B. | Hemispheric beam |
| C. | Spot beam |
| D. | Global beam |
| Answer» E. | |
| 58. |
As the height of a satellite orbit gets lower, the speed of the satellite ___________. |
| A. | Increases |
| B. | Decreases |
| C. | Remains the same |
| D. | None of the above |
| Answer» B. Decreases | |
| 59. |
Considered as the unsolved problem in satellite system |
| A. | Coverage |
| B. | Cost |
| C. | Access |
| D. | Privacy |
| Answer» E. | |
| 60. |
Is a loss of power of a satellite downlink signal due to earth’s atmosphere. |
| A. | Atmospheric loss |
| B. | Path loss |
| C. | Radiation loss |
| D. | RFI |
| Answer» C. Radiation loss | |
| 61. |
Collects very weak signals from a broadcast satellite |
| A. | Helical antenna |
| B. | Satellite dish |
| C. | LNA |
| D. | TWT |
| Answer» C. LNA | |
| 62. |
Assuming a minimum angle of elevation of 5°, a geosynchronous satellite remains in line-of-sight for __________ percentage of Earth's surface. |
| A. | 30.3 |
| B. | 42.4 |
| C. | 50 |
| D. | 25 |
| Answer» E. | |
| 63. |
Most of the communication satellites are stationed to the West of their service areas in order to reduce their |
| A. | eclipse period |
| B. | loss of power |
| C. | battery power provision |
| D. | mass of station-keeping fuel |
| Answer» D. mass of station-keeping fuel | |
| 64. |
Geosynchronous satellites are always launched in the equatorial plane because it is the only plane which provides |
| A. | 24-hour orbit |
| B. | stationary satellite |
| C. | global communication |
| D. | zero-gravity environs |
| Answer» D. zero-gravity environs | |
| 65. |
The expression for satellite link frequencies such as 4/6 GHz denotes that |
| A. | 4 GHz is the up-link and 6 GHz is the down-link frequency |
| B. | 4 GHz is the down-link and 6 GHz is the up-link frequency |
| C. | the system operates at a mean frequency of 5 GHz |
| D. | one frequency is used as a back up for the other |
| Answer» C. the system operates at a mean frequency of 5 GHz | |
| 66. |
India's first three-axis stabilised geostationary communication satellite is |
| A. | Rohini |
| B. | Aryabhatta |
| C. | Apple |
| D. | Bhaskara |
| Answer» D. Bhaskara | |
| 67. |
Presently, the worlds's largest and most advanced multi-purpose communication satellite is |
| A. | INSAT-2 |
| B. | Intelsat-V |
| C. | INSAT-ID |
| D. | Olympus-I |
| Answer» E. | |
| 68. |
India's Polar Satellite Launch vehicle (PSLV) to be ready in 1991 is designed to launch 1000 kg spacecraft into __________ orbit. |
| A. | geostationary |
| B. | equatorial |
| C. | polar |
| D. | sun-synchronous polar |
| Answer» E. | |
| 69. |
Space communication links are being increasingly moved into Ka-band (200-30 GHz) because it |
| A. | offers a much wider available bandwidth |
| B. | does not suffer from atmospheric at tenuation |
| C. | permits the use of smaller antenna |
| D. | does not suffer from rain attenuation |
| Answer» B. does not suffer from atmospheric at tenuation | |
| 70. |
Master control facility (MCF) for INSAT-2 series satellites is located at |
| A. | Madras |
| B. | New Delhi |
| C. | Leh |
| D. | Hassan |
| Answer» E. | |
| 71. |
For satellite transmission, analog signals may be converted into digital form with the help of |
| A. | modem |
| B. | transponder |
| C. | codec |
| D. | compandor |
| Answer» D. compandor | |
| 72. |
A telephone user while talking to a person via a satellite has to wait for reply for about __________ millisecond. |
| A. | 100 |
| B. | 270 |
| C. | 470 |
| D. | 540 |
| Answer» E. | |
| 73. |
System satellites orbit the Earth once in |
| A. | 24 hours |
| B. | 12 hours |
| C. | 1 hours |
| D. | 6 hours |
| Answer» B. 12 hours | |
| 74. |
In envelope detection of an AM waveform |
| A. | One side band and full-ampiitude carrier are needed |
| B. | Both side bands and full-amplitude carrier are needed |
| C. | Only two side bands are needed |
| D. | Upper side band and part of carrier are needed |
| Answer» C. Only two side bands are needed | |
| 75. |
The echo heard by a telephone user on a satellite channel can be removed by using |
| A. | a vocoder |
| B. | a multiplexer |
| C. | echo suppressor |
| D. | digital techniques |
| Answer» D. digital techniques | |
| 76. |
In selecting a satellite system, the First determining factor is its |
| A. | EIRP |
| B. | antenna size |
| C. | coverage a sea |
| D. | antenna gain |
| Answer» D. antenna gain | |
| 77. |
APPLE was into orbit on 19 th June 1981 by European Space Agency (ESA) from |
| A. | Cape Canaveral in Florida |
| B. | Kourou in French Guyana |
| C. | Canarvon in Western Australia |
| D. | Bangalore in South India |
| Answer» C. Canarvon in Western Australia | |
| 78. |
The 1150 kg geosynchronous satellite INSAT-IA parked 36000 km above India had greatly improved India's |
| A. | intelligence gathering capacity |
| B. | domestic communications |
| C. | meteorological capability |
| D. | both (b) and (c) |
| Answer» E. | |
| 79. |
Shannon's Law relates |
| A. | antenna gain to frequency |
| B. | noise power to bandwidth |
| C. | information-carrying capacity to S/N ratio |
| D. | transmission losses to noise |
| Answer» C. information-carrying capacity to S/N ratio | |
| 80. |
The distance of a synchronous satellite from Earth's surface is __________ km. |
| A. | 300 |
| B. | 10000 |
| C. | 35900 |
| D. | 5 |
| Answer» D. 5 | |
| 81. |
Low-orbit satellites are not used for communications because they |
| A. | produce sonic booms |
| B. | do not provide 24 hour/ day contact to the users on Earth |
| C. | heat up and melt |
| D. | none |
| Answer» D. none | |
| 82. |
In synchronous detection of an AM signal |
| A. | Carrier is completely suppressed |
| B. | Both side hands are suppressed |
| C. | Only one side band and part of carrier is suppressed |
| D. | One side band and full carrier is suppressed |
| Answer» D. One side band and full carrier is suppressed | |
| 83. |
The life time of a geosynchronous communication |
| A. | 5 |
| B. | 10 |
| C. | 20 |
| D. | 50 |
| Answer» C. 20 | |
| 84. |
The maximum signal propagation time of a geosynchronous satellite transmission is about __________ millisecond. |
| A. | 540 |
| B. | 270 |
| C. | 135 |
| D. | 1080 |
| Answer» C. 135 | |
| 85. |
Point out the false statement.Launching of geostationary experimental communication satellite has helped India to gain experience in |
| A. | Building, for the time, a body-stabilized geosynchronous communication satellite with its own apogee propulsion and control systems |
| B. | Attitude control and station management operations for a geostationary satellite |
| C. | Building launching rocket Ariane for putting APPLE in orbit |
| D. | Domestic communications on an experimental basis |
| Answer» D. Domestic communications on an experimental basis | |
| 86. |
A typical signal strength received from a geosynchronous communication satellite is of the order of a few |
| A. | milliwatts |
| B. | kilowatts |
| C. | picowatts |
| D. | watts |
| Answer» D. watts | |
| 87. |
The communication satellite INSAT-IB had to take up the job of INSAT-IA because the latter collapsed within __________ months of its launch. |
| A. | 12 |
| B. | 20 |
| C. | 5 |
| D. | 36 |
| Answer» D. 36 | |
| 88. |
The lowest frequency used in satellite communications is __________ GHz. |
| A. | 0.8 |
| B. | 3 |
| C. | 18 |
| D. | 30 |
| Answer» B. 3 | |
| 89. |
In satellite communication, highly directional antennas are used to |
| A. | direct the spot beam to a particular region of space on Earth |
| B. | strengthen the beam to overcome the cosmic noise |
| C. | make corrections in change of polarisation of the beam |
| D. | select a particular channel in transmission and reception |
| Answer» B. strengthen the beam to overcome the cosmic noise | |
| 90. |
The average noise temperature of Earth, as viewed from space, is __________ °K. |
| A. | 254 |
| B. | 303 |
| C. | 100 |
| D. | 500 |
| Answer» B. 303 | |
| 91. |
Regarding TASI which one of the following statements is wrong? |
| A. | It snatches the channel in his speech and may allocate it to another speaker needing it. |
| B. | The same speaker is reassigned a channel almost instantly when he speaks again even when the circuit is heavily loaded. |
| C. | It increases the overall utilization of the transmission channel |
| D. | Intercontinental callers sometimes confuse the effects of TASI with the effects of satellite delay. |
| Answer» C. It increases the overall utilization of the transmission channel | |
| 92. |
A few minutes disturbance in space communications occurs twice a year during Sunblinding when __________ are in line. |
| A. | Sun and satellite |
| B. | Sun and Earth station |
| C. | Satellite and Earth station |
| D. | Sun, satellite and Earth station |
| Answer» E. | |
| 93. |
Geosynchronous communication satellites travel around the earth in circular orbits with a forward speed of about __________ km/h. |
| A. | 11200 |
| B. | 0 |
| C. | 36000 |
| D. | 22800 |
| Answer» B. 0 | |
| 94. |
Phase modulation is commonly-used for data transmission mainly because |
| A. | phase can be varied from + 180° to 180° |
| B. | it is resistant to the effects of noise |
| C. | demodulation is very easy |
| D. | it gives highest data rates that can be transmitted over a given channel |
| Answer» C. demodulation is very easy | |
| 95. |
A satellite link uses different frequencies for receiving and transmitting in order to |
| A. | avoid interference from terrestrial microwave links |
| B. | avoid interference between its powerful transmitted signal and weak in coming signal |
| C. | minimise free-space losses |
| D. | maximise antenna gain |
| Answer» C. minimise free-space losses | |
| 96. |
Which of the following statement regarding link loss for a satellite is wrong? |
| A. | For fixed antenna, it is inversely proportional to f2 |
| B. | For fixed frequency, it is inversely proportional to the product of the antenna aperture areas |
| C. | For a given satellite operating at a given frequency, it is inversely proportional to |
| D. | Loss in down-link is negligible as compared to that in uplink |
| Answer» E. | |
| 97. |
Which statement out of the following statement is wrong? |
| A. | Attenuation of satellite signals by rain and fog varies almost inversely with the angle of elevation |
| B. | At 12/4, GHz link frequencies, signal power loss due to rain and fog is much greater than at 4/6 GHz frequencies |
| C. | The distance between satellite and Earth station varies slightly with angle of elevation |
| D. | At present 4/6 GHz geostationary satellites are being parked in geosynchronous, orbits at least 10° apart |
| Answer» E. | |
| 98. |
The number of days when Earth's shadow falls on a geosynchronous satellite is |
| A. | 88 |
| B. | 277 |
| C. | 5 |
| D. | 10 |
| Answer» B. 277 | |
| 99. |
At present, the radio-frequency band mainly used by most satellites is |
| A. | EHF |
| B. | UHF |
| C. | VHF |
| D. | SHF |
| Answer» E. | |
| 100. |
The traffic-handling capacity of an Earth station on the uplink depends on |
| A. | its EIRP |
| B. | satellite antenna gain |
| C. | noise associated with the satellite |
| D. | all of the above |
| Answer» E. | |