WorksheetsSATELLITE COMMUNICATION MCQs-I
Total questions: 40
Worksheet time: 1hrs 20mins
The earth area covered by a satellite radio beam is known as ……..
Beam width
Band width
Footprint
Zone
The owner of a communication satellite is usually required to keep the spacecraft on station at its assigned place in the geosynchronous orbit with an accuracy of __________ degree.
0.1
1.0
2.0
0.5
A satellite signal transmitted from a satellite transponder to earth’s station is ……….
Uplink
Downlink
Terrestrial
Earthbound
…………… is considered as the unsolved problem in satellite system.
Coverage
Cost
Access
Privacy
As the height of a satellite orbit gets lower, the speed of the satellite ……………
Increases
Decreases
Remains the same
None of the above
A transponder is a satellite equipment which ............. .
receives a signal from Earth station and amplifies
changes the frequency of the received signal
retransmits the received signal
does all of the above-mentioned functions
To make antenna more directional, either its size must be increased or .......... .
the number of its feed horns must be increased
the frequency of its transmission must be increased
its effective isotropic radiated power (EIRP) must be increased
its footprint must be increased
The discussing sharing of a communication satellite by many geographically dispersed Earth station, DAMA means ............ .
Demand-Assigned Multiple Access
Decibel Attenuated Microwave Access
Digital Analog Master Antenna
Dynamically-Assigned Multiple Access
Which one of the following statements regarding DSI is false?
It is a digital form of TASI
Though it is more efficient than TASI, it is much slower
A speaker has to wait (it at all) for only a few milliseconds for reallocation of channel
It has increased the capacity of satellite channels by a factor of 2.2 or more with out degrading speech quality
INTELSAT stands for ………….
Intel Satellite
International Telephone Satellite
International Telecommunications Satellite
International Satellite
Which law states that the square of the periodic time of orbit is perpendicular to the cube of the mean distance between the two bodies?
Newton’s 1st law
kepler’s first law
kepler’s second law
kepler’s third law
…………. is an artificial body that is projected from earth to orbit either earth (or) another body of solar systems.
Satellite
Moon
Sun
None of the above
Which law states that for equal time intervals, the satellite will sweep out equal areas in its orbital plane, focused at the barycenter.
Newton’s 1st law
Kepler’s first law
Kepler’s second law
Kepler’s third law
………… law states that the path followed by the satellite around the primary will be an ellipse.
Newton’s 1st law
Kepler’s first law
Kepler’s second law
Kepler’s third law
What are the limitations of FDMA-satellite access?
If the traffic in the downlink is much heavier than that in the uplink, then FDMA is relatively inefficient.
Compared with TDMA, FDMA has less flexibility in reassigning channels.
Carrier frequency assignments are hardware controlled
All of the above
What is meant by EIRP?
Equivalent Isotropic Radiated Power
Energy Isotropic Radiated Power
Equivalent Isotropic Resonance Power
None of these
………….. is necessary to prevent the bursts from overlapping.
Preamble
Guard time
Frame efficiency
Decoding quenching
In some phase detection systems, the phase detector must be allowed for some time to recover from one burst before the next burst is receiving by it. This waiting time is known as …………
Preamble
Guard time
Frame efficiency
Decoding quenching
What is meant by SCPC?
Single channel per carrier
Single carrier per channel
Single code per channel
None of these
For satellite communication, standard Earth stations have antenna diameters in the range of ………….. metre.
27.5 to 30
10 to 15
30 to 50
5 to 10
The most effective anti jamming technique is ………..
Frequency hopping
Spread-spectrum modulation
Key leverage
Once-only key
The Sun blots out the transmission of a geosynchronous satellite twice a year when satellite passes directly in front of it. This outage lasts for about ........... .
10 minutes on 5 consecutive days
5 minutes on 10 consecutive days
30 minutes for 5 consecutive days
one hour for 5 consecutive days
In satellite communication, frequency modulation is used because satellite channel has ............. .
Small bandwidth and negligible noise
Large bandwidth and severe noise
Maximum bandwidth and minimum noise
High modulation index
In communication satellites, the up-link normally operates at a higher frequency than the down-link because it .......... .
gives a narrow beam shining into space
results in lesser signal attenuation
gives better beam-shaping
is easier to polarize a high frequency beam
For global communication, the number of satellites needed is ........... .
1
3
10
5
The noise temperature of sky is about __________ °K.
100
273
0
30
In the context of error detection in satellite transmission, ARQ stands for ……………
Automatic Repeat Request
Automatic Relay Request
Accelerated Recovery Request
Automatic Radiation Quenching
To cover all inhabited regions of the Earth, the number of geosynchronous communication satellites required ............... .
5
3
10
2
A satellite link uses different frequencies for receiving and transmitting in order to ……..
avoid interference from terrestrial microwave links
avoid interference between its powerful transmitted signal and weak in coming signal
minimise free-space losses
maximise antenna gain
The distance of a synchronous satellite from Earth’s surface is ………….. km.
300
10000
35900
5
The traffic-handling capacity of an Earth station on the uplink depends on ………… .
its EIRP
satellite antenna gain
noise associated with the satellite
all of the above
System satellites orbit the Earth once in …………. hrs.
24
12
1
6
The lowest frequency used in satellite communications is ……….. GHz.
0.8
3
18
30
For satellite transmission, analog signals may be converted into digital form with the help of …………….. .
modem
transponder
codec
compandor
In satellite communication, highly directional antennas are used to ......... .
direct the spot beam to a particular region of space on Earth
strengthen the beam to overcome the cosmic noise
make corrections in change of polarisation of the beam
select a particular channel in transmission and reception
A few minutes disturbance in space communications occurs twice a year during Sunblinding when __________ are in line.
Sun and satellite
Sun and Earth station
Satellite and Earth station
Sun, satellite and Earth station
Regarding TASI which one of the following statements is wrong?
It snatches the channel in his speech and may allocate it to another speaker needing it.
The same speaker is reassigned a channel almost instantly when he speaks again even when the circuit is heavily loaded.
It increases the overall utilization of the transmission channel.
Intercontinental callers sometimes confuse the effects of TASI with the effects of satellite delay
Presently, the worlds’s largest and most advanced multi-purpose communication satellite is …………… .
INSAT-2
Intelsat-V
INSAT-ID
Olympus-I
The echo heard by a telephone user on a satellite channel can be removed by using ........... .
a vocoder
a multiplexer
echo suppressor
digital techniques
Phase modulation is commonly-used for data transmission mainly because .............. .
phase can be varied from + 180° to 180°
it is resistant to the effects of noise
demodulation is very easy
it gives highest data rates that can be transmitted over a given channel
