MCQs in Satellite Communications Part VII

This is the Multiples Choice Questions Part 7 of the Series in Satellite Communications as one of the Communications Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies, Communications Books, Journals and other Communications References.

Online Questions and Answers Topic Outline

• MCQs in Satellite System
• MCQs in Types of Satellite
• MCQs in Satellite Orbit
• MCQs in Uplink considerations
• MCQs in Demand Assignments Multiple Access
• MCQs in Antenna Tracking
• MCQs in Satellite Link Budgets
• MCQs in Satellite Path Loss
• MCQs in Satellite Figure of Merit
• MCQs in Ratio of Carrier to thermal Noise Power
• MCQs in Station Margin
• MCQs in VSAT

MCQs in Satellite Communications Series

Following is the list of multiple choice questions in this brand new series:

Satellite Communications MCQs

PART 1: MCQs from Number 1 – 50                        Answer key: PART I

PART 2: MCQs from Number 51 – 100                   Answer key: PART II

PART 3: MCQs from Number 101 – 150                 Answer key: PART III

PART 4: MCQs from Number 151 – 200                 Answer key: PART IV

PART 5: MCQs from Number 201 – 250                 Answer key: PART V

PART 6: MCQs from Number 251 – 300                 Answer key: PART VI

PART 7: MCQs from Number 301 – 350                 Answer key: PART VII

SEE: More Questions and Answers in Satellite Communications

Continue Practice Exam Test Questions Part VII of the Series

301. Which of the following is not an advantage of geosynchronous orbit?

• a. No need to switch from one satellite to another as satellites orbit overhead, therefore, no breaks of transmission due to switching times.
• b. High-altitude geosynchronous satellites can cover a much larger area
• c. Geosynchronous satellites require higher transmit powers and more sensitive receivers because of the longer distances and greater path loss.
• d. Satellite remains almost stationary in respect to a given earth station, therefore, expensive tracking equipment is not required at the earth stations.

302. Which of the following parameters (height of the satellite from earth, travel time, rotation period, and the satellite’s line of sight) refer to low-altitude satellite?

• a. 19,000 – 25,000 mi; 6,879 mi/hr; 24 hr; and 24-h availability time, respectively
• b. 6,000 – 12,000 mi; 12,189 mi/hr; 5 – 12 hr; and 2- 4 hr per orbit, respectively
• c. 100 – 300 mi; 17,500 mi/hr; 1 ½ hr, and ¼ or less per orbit, respective
• d. 50 – 95 mi; 25,600 mi/hr, ½ hr; and 1/8 or less per orbit, respectively

303. There are two primary classifications of communications satellite; one uses the angular momentum of its spinning body to provide roll and yaw relative to earth’s surface while an internal subsystem provides roll and yaw stabilization. What are they?

• a. gyroscopic satellites
• b. delayed repeater satellites
• c. passive and active satellites
• d. spinners and three-axis stabilizer satellites

304. How do radiation patterns or beams from a satellite antenna categorized?

• a. Spot
• b. Earth
• c. Zonal
• d. All of these

305. A ____________ satellite with an orbital period of one sidereal day or nominally, 24 h

• a. Bent-pipe satellite
• b. Processing satellite
• c. Geostationary satellite
• d. ANIK-D communications satellite

306. 19,000 – 25,000 mi height; 6, 879 mi/hr travel time; 24-hr rotation; and 24-hr availability time belong to what satellite?

• a. Low-altitude satellites (circular orbit)
• b. Medium-altitude satellites (elliptical orbit)
• c. High-altitude satellites (geosynchronous orbit)
• d. GLONASS

307. An orbit when the satellite rotates in a path above the equator.

• a. Polar orbit
• b. Inclines orbit
• c. Equatorial orbit
• d. Geosynchronous orbit

308. Orbiting satellite system in Russia which means “lightning” or “news flash”, used for television broadcasting. It uses a highly inclined elliptical orbit with apogee at about 40,000 km and perigee at about 1,000 km.

• a. Molniya system
• b. Molnya system
• c. Molnia system
• d. All are correct

309. Polar and inclined orbits refer to what?

• a. Any other orbital path, and rotation above the equator, respectively
• b. Any other orbital path, and rotation that takes over the north and south poles, respectively
• c. Rotation that takes over the north and south poles, and any other orbital path, respectively
• d. Rotation above the equator, and rotation that takes over the north and south poles, respectively

310. ____________ means the farthest distance from earth a satellite orbit reaches while ____________ is the minimum distance.

• a. Apogee and perigee, respectively
• b. Perigee and apogee, respectively
• c. A and B are the same
• d. None of these

311. Refers to the line joining the perigee and apogee through the center of the earth

• a. Line of sight
• b. Line of nodes
• c. Equatorial nelt
• d. Line of apsides

312. The point where the orbit crosses the equatorial plane going from north to south; and the point where the orbit crosses the equatorial plane going from south to north refer to

• a. Ascending node
• b. Descending node
• c. Ascending node and descending node, respectively
• d. Descending node and ascending node, respectively

313. What is the line joining the ascending and descending nodes through the center of the earth?

• a. Line of apsides
• b. Line of nodes
• c. Line of shoot
• d. Line of sight

314. Refers to the horizontal pointing of an antenna.

• a. Look angle
• b. Elevation
• c. Azimuth
• d. Spot

315. What is meant by the angle of elevation?

• a. The angle formed between the direction of travel of a wave radiated from an earth station antenna and the horizontal.
• b. The horizontal pointing of an antenna
• c. The angle subtended at the earth station antenna between the satellite and the horizontal
• d. A or C is right

316. The range of frequencies used by communications satellites?

• a. From 1 GHz up to 3 GHz
• b. From 1 GHz up to 30 GHz
• c. From 30 GHz up to 300 GHz
• d. From 300 GHz up to 350 GHz

317. Otherwise considered as radio repeater in the sky.

• a. Transponder
• b. Satellite
• c. Sputnik
• d. Courier

318. How does interference between uplink and downlink signals be prevented?

• a. By using different ground stations
• b. By using different satellites
• c. By using different carrier frequencies
• d. All of these

319. An electronic system called transponder of the communications satellite is used

• a. For frequency translations
• b. To retransmit signals
• c. To receive signals
• d. All of the above

320. What do you call of the signal path from the transmitter to satellite and from the satellite to earth-based receiver?

• a. Downlink and uplink, respectively
• b. Downlink
• c. Uplink and downlink, respectively
• d. Uplink

321. Why is it that the uplink is always higher in frequency than the downlink?

• a. Because the uplink suffers greater spreading or free-space loss of frequency than its lower counterpart
• b. Since an earth station aims upward with well-controlled antenna sidelobes
• c. A and B are correct
• d. None of these

322. What is frequency hopping?

• a. A form of CDMA where a digital code is used to continually change the frequency of the carrier
• b. Available bandwidth is partitioned into smaller frequency bands and the total transmission time is subdivided into smaller time slots
• c. Each earth stations within a CDMA network is assigned a different frequency hopping pattern in which each transmitter hops or switched from one frequency band to the next according to their assigned pattern
• d. All of these

323. What is meant by satellite footprint?

• a. Is the earth area that the satellite can receive from or transmit to
• b. Is the function of both the satellite orbit and height, and the type of antenna the satellite uses.
• c. The geographical representation of the satellite antenna’s radiation pattern.
• d. All of the above

324. What (is)are the advantage(s) using 1-GHz and higher frequencies?

• a. Large amount of information can be sent due to large available bandwidth
• b. Propagation characteristics are very consistent
• c. Signal wavelengths are shorter
• d. All of these are correct

325. What is meant by link budget?

• a. The sum of all the signal gains and losses along the way.
• b. The difference of the signal gains and losses along the way
• c. Identifies the system parameters and is used to determine the projected C/N and E_b/N_o ratios at both the satellite and earth stations receivers for a given modulation scheme and desired P_q.
• d. A or C is right

326. How can satellite maintains its desired orbit consistently?

• a. Using small on-board rocket trusters
• b. Through using guidance system
• c. By telemetry channel
• d. All of these

327. A satellite consists of any subsystem functions incorporated into a single system. What is the subsystem responsible for providing the primary dc power and the regulated, secondary supply voltages for the satellite circuits?

• a. Communication channel subsystem
• b. Telemetry subsystem
• c. Power subsystem
• d. Antennas

328. How do communications satellites powered?

• a. By a bank of batteries whose charge is maintained by an array of solar cells
• b. Liquid fuel
• c. Nuclear
• d. AC power

329. _____________ is the total power consumption for the satellite operation?

• a. About 10 W
• b. About 150 W
• c. About 2000 W
• d. About 25000 W

330. As the height of a satellite orbits gets lower, the speed of the satellite

• a. Increases
• b. Decreases
• c. Remains the same
• d. None of the above

331. The main function of a communications satellite is the

• a. Repeater
• b. Reflector
• c. Beacon
• d. Observation platform

332. The key electronic component in a communications satellite is the

• a. Telemetry
• b. On-board computer
• c. Command and control system
• d. Transponder

333. A circular orbit around the equator with a 24-h period is called a(n)

• a. Elliptical orbit
• b. Geostationary orbit
• c. Polar orbit
• d. Transfer obit

334. 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

335. The height of a satellite in a synchronous equatorial orbit is

• a. 100 mi
• b. 6800 mi
• c. 22,300 mi
• d. 35, 860 mi

336. 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

337. The main power sources for a satellite are

• a. Batteries
• b. Solar cells
• c. Fuel cells
• d. Thermoelectric generators

338. The maximum height of an elliptical orbit is called the

• a. Perigee
• b. Apex
• c. Zenith
• d. Apogee

339. 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

340. The satellite subsystems that monitors and controls the satellite is the

• a. Propulsion subsystem
• b. Power subsystem
• c. Communications subsystem
• d. Telemetry, tracking, and command subsystem

341. The basic technique used to stabilized a satellite is

• a. Gravity-forward motion balance
• b. Spin
• c. Thrusters control
• d. Solar panel orientation

342. The jet thrusters are usually fired to

• a. Maintain altitude
• b. Put the satellite into the transfer orbit
• c. Inject the satellite into the geosynchronous orbit
• d. Bring the satellite back to the earth

343. Most commercial satellite activity occurs in which band(s)?

• a. L
• b. C and Ku
• c. X
• d. S and P

344. How can multiple earth stations share a satellite on the same frequencies?

• a. Frequency reuse
• b. Multiplexing
• c. Mixing
• d. They can’t

345. The typical bandwidth of a satellite band is

• a. 36 MHz
• b. 40 MHz
• c. 70 MHz
• d. 500 MHz

346. Which of the following is not usually a part of a transponder?

• a. LNA
• b. Mixer
• c. Modulator
• d. HPA

Complete List of MCQs in Communications Engineering per topic

Series of Multiple Choice Questions in Electronics Systems and Technologies

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