Satellite Communications MCQ
101. It is a celestial body that orbits around a planet.
- A. Primary body
- B. Satellite
- C. Heavenly bodies
- D. Quasars
102. It is a position and timing service that is available to all GPS users on a continuous, worldwide basis with no direct charge.
- A. PPI
- B. PPS
- C. SPS
- D. SSP
103. The geometric shape of a non-circular orbit of a satellite is ____.
- A. Ellipse
- B. Parabolic
- C. Hyperbolic
- D. Paraboloid
104. The circuit that provides channelization in a transponder is the
- A. Mixer
- B. Local oscillator
- C. Bandpass filter
- D. HPA
105. The three axes referred to the three-axis attitude stabilization are; except
- A. Pitch
- B. Yaw
- C. Roll
- D. Speed
106. A ground station is operating to a geostationary satellite at a 5 degrees angle of elevation. Calculate the round-trip time between ground station to satellites in a geostationary orbit.
- A. 456.45 ms
- B. 275.58 ms
- C. 137.79 ms
- D. 126.89 ms
107. The escape velocity of the earth is approximately
- A. 30,000 km/hr
- B. 25,000 mi/hr
- C. 35,000 m/s
- D. 25,000 km/hr
108. A satellite radio repeater is called ____.
- A. Repeater
- B. Transponder
- C. Satellite
- D. Mixer
109. Calculate the angle of declination for an antenna using a polar mount at a latitude of 45 degrees.
- A. 3.2 degrees
- B. 1.3 degrees
- C. 4.2 degrees
- D. 6.81 degrees
110. The time transfer accuracy used with reference to the Universal Transmitter Mercator Grid is ____.
- A. UTC
- B. UTMG
- C. GMT
- D. UTM
111. It is caused by the inertia of the satellite balanced by the earth’s gravitational pull.
- A. Centrifugal force
- B. Centripetal force
- C. Speed
- D. Earth’s rotation
112. In satellites, it includes control mechanism that support the payload operation.
- A. Bus
- B. Payload
- C. Ground segment
- D. Space segment
113. A satellite transmitter operates at a 4 GHz with a transmitter power of 7W and an antenna gain of 40 dBi. The receiver has antenna gain of 30 dBi, and the path length is 40,000 km. calculate the signal strength at the receiver.
- A. -88 dBm
- B. -98 dBm
- C. -77 dBm
- D. -79.8 dBm
114. The satellite subsystem that monitors and controls the satellite is the
- A. Propulsion system
- B. Power subsystem
- C. Communications subsystem
- D. Telemetry, tracking, and command subsystems
115. Standard positioning service has time transfer accuracy to Universal Transfer Mercator Grid within ____.
- A. 140 nanoseconds
- B. 340 nanoseconds
- C. 230 nanoseconds
- D. 530 nanoseconds
116. A satellite remains in orbit because the centrifugal force caused by its rotation around the Earth is counterbalanced by Earth’s ____.
- A. Centripetal force
- B. Inertia
- C. Gravitational pull
- D. Speed
117. A TVRO installation for use with C-band satellite (download frequency at 4 GHz), has a diameter of about 3.5 meters and an efficiency of 60%. Calculate the gain.
- A. 41 dB
- B. 19 dB
- C. 29 dB
- D. 9 dB
118. Which of the following is not a typical output from the GPS receiver?
- A. Latitude
- B. Speed
- C. Altitude
- D. Longitude
119. The law that states that a satellite will orbit a primary body following an elliptical path.
- A. 1st law of Kepler
- B. 2nd law of Kepler
- C. 3rd law of Kepler
- D. 4th law of Kepler
120. Telephone communication takes place between two earth stations via a satellite that is 40,000 km from each station. Suppose Bill, at station 1, asks a question and Sharon, at station 2, answers immediately, as soon as she hears the question. How much time elapses between the end of Bill’s question and the beginning of Sharon’s reply, as heard by Bill?
- A. 0.26 sec
- B. 3.2 sec
- C. 0.52 sec
- D. 1.6 sec
121. In GPS, it is accomplished by manipulating navigation message orbit data (epsilon) and/or the satellite clock frequency (dither).
- A. Selective availability
- B. Reverse error notification
- C. Forward error notification
- D. Two dimensional reporting
122. The modulation normally used with digital data is
- A. AM
- B. FM
- C. SSB
- D. QPSK
123. Kepler’s 2nd law is known as
- A. Law of gravity
- B. Law of areas
- C. Newton’s law of motion
- D. Harmonic law
124. A receiving antenna with a gain of 40 dB looks at a sky with a noise temperature of 15 K. the loss between the antenna and the LNA input, due to the feedhorn is 0.4 dB, and the LNA has a noise temperature of 40K. Calculate the G/T?
- A. 13.4 dB
- B. 39 dB
- C. 20.6 dB
- D. 11.2 dB
125. The operational satellites of Navstar GPS are revolving around Earth in ____ orbital planes.
- A. 4
- B. 3
- C. 5
- D. 6
126. Kepler’s 3rd law is also known as
- A. Law of gravity
- B. Law of areas
- C. Newton’s law of motion
- D. Harmonic law
127. The basic technique used to stabilize a satellite is
- A. Gravity-forward motion balance
- B. Spin
- C. Thruster control
- D. Solar panel orientation
128. Calculate the length of the path to a geostationary satellite from an earth station where the angle of elevation is 30 degrees.
- A. 55 x 10^3 km
- B. 13 x 10^3 km
- C. 23 x 10^3 km
- D. 39 x 10^3 km
129. Navstar GPS is a ____.
- A. LEO
- B. MEO
- C. HEO
- D. GEO
130. The satellite is orbiting in the same direction as the Earth’s rotation and at angular velocity greater than that of the Earth.
- A. Retrograde
- B. Synchronous
- C. Posigrade
- D. Asynchronous
131. Find the orbital period of the satellite in a circular orbit 500 km above the Earth’s surface
- A. 1.6 hrs
- B. 3.2 hrs
- C. 2.4 hrs
- D. 6.4 hrs
132. Satellite orbiting in the opposite direction as the Earth’s rotation and at angular velocity less than that of the Earth
- A. Asynchronous
- B. Synchronous
- C. Posigrade
- D. Retrograde
133. A transponder that demodulates the baseband signals and then demodulates a carrier is known as ____ transponder.
- A. Single-conversion
- B. Double-conversion
- C. Regenerative
- D. Degenerative
134. Low Earth Orbit (LEO) satellite orbits around the earth at a height of approximately ____.
- A. 3000 miles
- B. 1000 miles
- C. 575 miles
- D. 370 miles
135. Power amplification in a transponder is usually provided by
- A. klystron
- B. TWT
- C. Transistor
- D. Magnetron
136. Which of the following clocks is developed for Galileo satellite?
- A. Cesium Atomic Frequency Standard
- B. Rubidium Atomic Frequency Standard
- C. Ruby Atomic Frequency Standard
- D. Hydrogen Frequency Standard
137. Master control station of GPS is located in ____.
- A. Colorado
- B. California
- C. Alaska
- D. New York
138. Medium Earth Orbit (MEO) satellite orbits around the earth at a height approximately ____.
- A. 3,000 miles to 6,000 miles
- B. 4,000 miles to 8,000 miles
- C. 6,000 miles to 12,000 miles
- D. 8,000 miles to 10,000 miles
139. A satellite stays in orbit because the following two factors are balanced
- A. Satellite weight and speed
- B. Gravitational pull and inertia
- C. Centripetal force and speed
- D. Satellite weight and the pull of the moon and sun
140. A ____ circuit in the transponder performs the frequency conversion.
- A. HPA
- B. Mixer
- C. Local oscillator
- D. LPA
141. Geosynchronous satellites are high-altitude earth-orbit satellites with heights about ____.
- A. 22,300 miles
- B. 21,000 miles
- C. 8,000 miles
- D. 10,400 miles
142. The input circuit to a transponder is the ____.
- A. BPF
- B. HPA
- C. LPA
- D. Any of these
143. The access scheme used by GPS
- A. FDMA
- B. OFDMA
- C. TDMA
- D. CDMA
144. The point in an orbit which is located farthest from earth
- A. Perigee
- B. Apogee
- C. Line of apsides
- D. Point of shoot
145. Using very narrow beamwidth antennas to isolate signals on the same frequency is known as ____.
- A. Spatial isolation
- B. Footprint
- C. Frequency reuse
- D. Boresight
146. The point in an orbit which is located closest to Earth
- A. Point of shoot
- B. Apogee
- C. Line of apsides
- D. Perigee
147. The most popular satellite frequency range is 4 to 6 GHz and is called the ____ band.
- A. C
- B. L
- C. Ka
- D. Ku
148. All satellites rotate around the earth in an orbit that forms a plane that passes through the center of gravity of earth called ____.
- A. Focus
- B. Geocenter
- C. Orbit
- D. Center
149. In satellite communications, the type of modulation used in voice and video signals is
- A. AM
- B. FM
- C. SSB
- D. QPSK
150. In satellite communications, type of orbit which is virtually all orbits except those travel directly above the equator or directly over the North or the South poles.
- A. Equatorial orbit
- B. Polar orbit
- C. Geosynchronous orbit
- D. Inclined orbit
Satellite Communications MCQ-answers
101. Satellite
102. SPS
103. Ellipse
104. Bandpass filter
105. Speed
106. 275.58 ms
107. 25,000 mi/hr
108. Transponder
109. 6.81 degrees
110. UTC
111. Centripetal force
112. Bus
113. -88 dBm
114. Telemetry, tracking, and command subsystems
115. 340 nanoseconds
116. Gravitational pull
117. 41 dB
118. Speed
119. 1st law of Kepler
120. 0.52 sec
121. Selective availability
122. QPSK
123. Law of areas
124. 20.6 dB
125. 6
126. Harmonic law
127. Spin
128. 39 x 10^3 km
129. MEO
130. Posigrade
131. 1.6 hrs
132. Retrograde
133. Regenerative
134. 370 miles
135. TWT
136. Rubidium Atomic Frequency Standard
137. Colorado
138. 6,000 miles to 12,000 miles
139. Gravitational pull and inertia
140. Mixer
141. 22,300 miles
142. LPA
143. CDMA
144. Apogee
145. Spatial isolation
146. Perigee
147. C
148. Geocenter
149. FM
150. Inclined orbit
