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Home Electronics and Communication Engineering Satellite Communication Comments

  • Question
  • The expression for satellite link frequencies such as 4/6 GHz denotes that


  • Options
  • 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

  • Correct Answer
  • 4 GHz is the down-link and 6 GHz is the up-link frequency 


  • Satellite Communication problems


    Search Results


    • 1. Most of the communication satellites are stationed to the West of their service areas in order to reduce their

    • Options
    • A. eclipse period
    • B. loss of power
    • C. battery power provision
    • D. mass of station-keeping fuel
    • Discuss
    • 2. A satellite link uses different frequencies for receiving and transmitting in order to

    • Options
    • 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
    • Discuss
    • 3. Mark out the WRONG statement.
      As compared to FDMA, the demand assignment system TDMA

    • Options
    • A. Needs very high-speed burst modems
    • B. Faces no problems caused by intermodulation of carriers so that transponder can be used at its full power
    • C. Needs high-speed manipulation of bit streams
    • D. Is less flexible so that channels of widely different capacities cannot used and intermixed
    • Discuss
    • 4. Presently, the worlds's largest and most advanced multi-purpose communication satellite is

    • Options
    • A. INSAT-2
    • B. Intelsat-V
    • C. INSAT-ID
    • D. Olympus-I
    • Discuss
    • 5. Assuming a minimum angle of elevation of 5°, a geosynchronous satellite remains in line-of-sight for __________ percentage of Earth's surface.

    • Options
    • A. 30.3
    • B. 42.4
    • C. 50
    • D. 25
    • Discuss
    • 6. In satellite communication, highly directional antennas are used to

    • Options
    • 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
    • Discuss
    • 7. India's Polar Satellite Launch vehicle (PSLV) to be ready in 1991 is designed to launch 1000 kg spacecraft into __________ orbit.

    • Options
    • A. geostationary
    • B. equatorial
    • C. polar
    • D. sun-synchronous polar
    • Discuss
    • 8. Geosynchronous communication satellites travel around the earth in circular orbits with a forward speed of about __________ km/h.

    • Options
    • A. 11200
    • B. 0
    • C. 36000
    • D. 22800
    • Discuss
    • 9. Phase modulation is commonly-used for data transmission mainly because

    • Options
    • 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
    • Discuss
    • 10. When a communication satellite passes into Earth's shadow, its temperature drops to about __________ ° K.

    • Options
    • A. 273
    • B. 243
    • C. 170
    • D. 123
    • Discuss


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