Satellite Communications MCQ
51. The main function of a communications satellite is a/ an
- A. repeater
- B. reflector
- C. beacon
- D. observation platform
52. The key electronic component in a communications satellite is the
- A. telemetry equipment
- B. on-board computer
- C. command and control system
- D. transponder
53. A circular orbit around the equator with a 24-h period is called a/an
- A. elliptical orbit
- B. geostationary orbit
- C. polar orbit
- D. transfer orbit
54. A satellite stay in orbit because the following two factors are balanced
- A. Satellite weight and speed
- B. Gravitational force and centrifugal force
- C. Centripetal force and speed
- D. Satellite weight and the pull of the moon and sun
55. What is the height of a satellite in a synchronous equatorial orbit?
- A. 42000 mi
- B. 6800 mi
- C. 22,300 mi
- D. 35,860 mi
56. Most satellites operate in which frequency band?
- A. 30 to 300 MHz
- B. 300 MHz to 3 GHz
- C. 3 GHz to 30 GHz
- D. Above 300 GHz
57. The main power sources for a satellite are
- A. batteries
- B. solar cells
- C. fuel cells
- D. thermoelectric generators
58. The maximum height of an elliptical orbit is called the
- A. Perigee
- B. Apex
- C. Zenith
- D. Apogee
59. Batteries are used to power all satellite subsystems
- A. at all times
- B. only during emergencies
- C. during eclipse periods
- D. to give the solar arrays a rest
60. The satellite subsystem that monitors and controls the satellite is the
- A. propulsion subsystem
- B. power subsystem
- C. communications subsystem
- D. telemetry, tracking, and command subsystem
61. What is the basic technique used to stabilize a satellite?
- A. Gravity-forward motion balance
- B. Spin
- C. Thruster control
- D. Solar panel orientation
62. The jet thrusters are usually fired to
- A. maintain altitude
- B. put the satellite into the transfer orbit
- C. inject the satellite in the geosynchronous orbit
- D. bring the satellite back to earth.
63. Most commercial satellite activity occurs in which band(s)?
- A. L
- B. C and Ku
- C. X
- D. S and P
64. How can multiple earth stations share a satellite on the same frequencies?
- A. Frequency reuse
- B. Multiplexing
- C. Mixing
- D. Frequency hopping
65. What is the typical bandwidth of a satellite band?
- A. 36 MHz
- B. 40 MHz
- C. 70 MHz
- D. 500 MHz
66. Which of the following is not usually a part of a transponder are defined by the
- A. LNA
- B. Mixer
- C. Modulator
- D. HPA
67. The satellite communications channels in a transponder are defined by the
- A. LNA
- B. bandpass filter
- C. mixer
- D. input signals
68. The HPAs in most satellite are
- A. TWTs
- B. Klystrons
- C. Vacuum tubes
- D. Magnetrons
69. The physical location of a satellite is determined by its
- A. distance from the earth
- B. latitude and longitude
- C. reference to the stars
- D. position relative to the sun
70. The receive GCE system in an earth station performs what function(s)?
- A. Modulation and multiplexing
- B. Up conversion
- C. Demodulation and demultiplexing
- D. Down conversion
71. Which of the following types of HPA is not used in earth stations?
- A. TWT
- B. Transistor
- C. Klystron
- D. Magnetron
72. What is the common up-converter and down-converter IF?
- A. 36 MHz
- B. 40 MHz
- C. 70 MHz
- D. 500 MHz
73. What type of modulation is used on voice and video signals?
- A. AM
- B. FM
- C. SSB
- D. QPSK
74. What modulation is normally used with digital data?
- A. AM
- B. FM
- C. SSB
- D. QPSK
75. Which of the following is not a typical output from a GPS receiver?
- A. Latitude
- B. Speed
- C. Altitude
- D. Longitude
76. The total space loss of transmission and reception for two ground stations with uplink
frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is
frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is
- A. 403 dB
- B. 100 dB
- C. 20 dB
- D. 215 dB
77. The maximum propagation delay of a geostationary satellite is
- A. 278 ms
- B. 239 ms
- C. 300 ms
- D. 250 ms
78. The total propagation delay time from transmission to reception of signals from a ground
transmitter to ground receiver with angle of elevation at 10 degrees respectively is
transmitter to ground receiver with angle of elevation at 10 degrees respectively is
- A. 273 ms
- B. 239 ms
- C. 275 ms
- D. 260 ms
79. A satellite which simply reflects the signal without further amplification
- A. Passive satellite
- B. Active satellite
- C. Geostationary satellite
- D. Domestic satellite
80. Essentially a satellite ___________ is a radio repeater in the sky
- A. transponder
- B. comparator
- C. duplexer
- D. billboard
81. Satellite the orbits in a circular pattern with an angular velocity equal to that of the earth
- A. Geostationary
- B. Early Bird I
- C. Syncorn I
- D. Stationary satellite
82. Satellite that provide services within a single country
- A. Domsat
- B. Comsat
- C. Regional
- D. Global
83. The round-trip propagation delay between two earth stations through a geosynchronous satellite is
- A. 500 to 600 ms
- B. 300 to 400 ms
- C. 600 to 700 ms
- D. 400 to 500 ms
84. The signal path from earth station satellite
- A. Uplink signal
- B. Reflected signal
- C. Incident signal
- D. Downlink signal
85. Designed to receive a signal from a transmitting station on the ground and retransmit it to a
receiving station located elsewhere
receiving station located elsewhere
- A. Communication satellite
- B. Repeater
- C. Relay station
- D. Transponder
86. The signal path from satellite to earth-based receiver.
- A. Downlink signal
- B. Uplink signal
- C. Incident signal
- D. Reflected signal
87. A satellite position is measured by its __________ angle with respect to the horizon.
- A. elevation
- B. depression
- C. azimuth
- D. critical
88. The ________ angle measures the satellite position clockwise from the direction of true north.
- A. azimuth
- B. elevation
- C. depression
- D. critical
89. incidentally propose the geostationary scheme or orbit of the satellite in 1940s
- A. Arthur Clarke
- B. Carl Friedrich Gauss
- C. Samuel Morse
- D. Stephen Gray
90. When the satellite are spaced 4˚ of the 360˚ complete circle, how many parking spaces or orbit slots are available?
- A. 90
- B. 85
- C. 95
- D. 80
91. The control routine necessary to keep the satellite in position is referred to as
- A. station keeping
- B. station tracking
- C. station monitoring
- D. station maintaining
92. Refers to the satellite orientation with respect to the earth
- A. Satellite altitude
- B. Satellite position
- C. Satellite location
- D. Satellite orbit
93. The first intelsat satellite that was launched in 1965 was named
- A. Early Bird I
- B. Echo
- C. Telstar I
- D. Courier
94. The first satellite launched for a geosynchronous orbit but unfortunately lost during orbit injection
- A. Syncom I
- B. Telstar I
- C. Sputnik I
- D. Early Bird I
95. When the elevation angle of a geostationary satellite is 23˚ and the transmitting frequency is 3840 MHz, what is the free space loss in dB?
- A. 196 dB
- B. 200 dB
- C. 150 dB
- D. 100 dB
96. What is the propagation delay when a signal is transmitter by an earth station to a geosynchronous satellite about 38,500 km above earth’s
equator and then received by the same earth station?
equator and then received by the same earth station?
- A. 256 msec
- B. 128 msec
- C. 300 msec
- D. 400 msec
97. What is the free space attenuation of a satellite communications system operating at 36,000 km above the earth at 5.0 GHz?
- A. 198 dB
- B. 202 dB
- C. 142 dB
- D. 138 dB
98. Which of the following is the most common application of satellite?
- A. Surveillance
- B. Military application
- C. Communications
- D. Newscasting
99. Descending pass for a satellite means a pass from
- A. North to South
- B. South to North
- C. East to West
- D. West to East
100. Geostationary stationary satellites are located ___________ with respect to the equator.
- A. 0˚ longitude
- B. 0˚ latitude
- C. 90˚ latitude
- D. 45˚ latitude
Satellite Communications MCQ (51-100) - Answers
51. repeater 52. transponder 53. geostationary orbit 54. Gravitational force and centrifugal force
55. 22,300 mi 56. 3 GHz to 30 GHz 57. solar cells 58. Apogee 59. during eclipse periods
60. telemetry, tracking, and command subsystem 61. Spin 62. maintain altitude 63. C and Ku
64. Frequency reuse 65. 500 MHz 66. Modulator 67. bandpass filter 68. TWTs 69. latitude and longitude
70. Demodulation and demultiplexing 71. Magnetron 72. 70 MHz 73. FM 74. QPSK 75. Speed
76. 403 dB 77. 278 ms 78. 273 ms 79. Passive satellite 80. transponder 81. Geostationary
82. Domsat 83. 500 to 600 ms 84. Uplink signal 85. Communication satellite 86. Downlink signal
87. elevation 88. azimuth 89. Arthur Clarke 90. 90 91. station keeping 92. Satellite altitude
93. Early Bird I 94. Syncom I 95. 196 dB 96. 256 msec 97. 198 dB 98. Communications 99. North to South
100. 0˚ latitude
