Satellite Communication MCQs : This section focuses on the "Satellite Communication". These Multiple Choice Questions (MCQs) should be practiced to improve the Satellite Communication skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
What is the reason for shifting from c band to ku band in satellite communication?
A. Lesser attenuation
B. Less power requirements
C. More bandwidth
D. Overcrowding
Question 2
Of the four INSAT-I satellites planned by India so for, only __________ has proved to be successful.
A. INSAT-IA
B. INSAT-IB
C. INSAT-IC
D. INSAT-ID
Question 3
The useful operational life of INSAT-IB (launched in 1983) is expected to end by
A. 1992-93
B. 1991-92
C. 1989-90
D. 1993-94
Question 4
The present total cost per watt of power generation in geosynchronous orbit is nearly Rs.
A. 20
B. 50
C. 100
D. 5
Question 5
Which one of the following statements regarding compandor is FALSE?
A. It compresses the higher-amplitude parts of a signal before modulation and expands them back to normal again after demodulation.
B. It gives preferential treatment to the weaker parts of the signal
C. For weaker signals it gives a poor ratio of signal strength to quantizing error
D. Weaker signals, traverse more quantum steps than they would do otherwise and so quantizing error is reduced.
Question 6
In communication satellites, the up-link normally operates at a higher frequency than the down-link because it
A. gives a narrow beam shining into space
B. results in lesser signal attenuation
C. gives better beam-shaping
D. is easier to polarize a high frequency beam
Question 7
A geosynchronous satellite
A. has the same period a that of the Earth
B. has a circular orbit
C. rotates in the equatorial plane
D. has all of the above
Question 8
Why are techniques like frequency reuse and spatial isolation carried out?
A. Reduce traffic load
B. More gain
C. High speed
D. Error detection
Question 9
The quality of a space-link is measured in terms of the __________ ratio.
A. C/N
B. S/N
C. G/T
D. EIRP
Question 10
Spatial-division multiple access (SDMA) depends on satellite location and not frequency.
A. True
B. False
Question 11
A communication satellite is a repeater between
A. a transmitting station and a receiving station
B. a transmitting station and many receiving station
C. many transmitting station and many receiving station
D. none
Question 12
A certain sound has 10000 times more energy than another sound. The number of times it would sound stronger to a listener is
A. 40
B. 10000
C. 100
D. 10
Question 13
Satellite launch sites are invariably located on Eastern seaboards to ensure that
A. launch takes place eastward
B. expenditure of propulsion fuel is reduced during plane changing
C. the satellite achieves circular orbit quickly
D. spent rocket motor and other launcher debris falls into the sea
Question 14
The geostationary communication satellite APPLE is parked in the equatorial orbit at
A. 102° E longitude over Sumatra
B. 90° E longitude over Bangladesh
C. 74° E longitude over India
D. 67° E longitude over Pakistan
Question 15
A 20 m antenna gives a certain uplink gain at frequencies of 4/6 GHz. For getting same gain in the 20/30 GHz band, antenna size required is metre.
A. 100
B. 4
C. 1
D. 10
Question 16
The satellite that is used as a relay to extend communication distance is called as __________
A. Relay satellites
B. Communication satellites
C. Repeater satellites
D. Geosynchronous satellites
Question 17
Radio broadcasting is a familiar example of
A. space multiplexing
B. time multiplexing
C. frequency multiplexing
D. none of the above
Question 18
In satellite communication, frequency modulation is used because satellite channel has
A. small bandwidth and negligible noise
B. large bandwidth and severe noise
C. maximum bandwidth and minimum noise
D. high modulation index
Question 19
A geostationary satellite is one which
A. hangs motionless in space about 36000 km about Earth
B. travels around the Earth in 24 hours
C. remains stationary above the Earth
D. appears stationary to everybody on Earth
Question 20
What is the maximum theoretical data rate if a transponder is used for binary transmission and has a bandwidth of 36MHz?
A. 32Mpbs
B. 72Mpbs
C. 36Mpbs
D. 12Mpbs
Question 21
Why are VHF, UHF, and microwave signals used in satellite communication?
A. More bandwidth
B. More spectrum space
C. Are not diffracted by the ionosphere
D. Economically viable
Question 22
In the case of a 70-MHz IF carrier for a transponder bandwidth of 36 MHz, energy must lie between MHz.
A. 34 and 106
B. 52 and 88
C. 106 and 142
D. 34 and 142
Question 23
Which of the following factor does NOT contribute to the drift of a geostationary satellite from its stationary position in space?
A. Pressure of solar radiations
B. Gravitational changes due to Sun and Moon
C. Oblateness of the Earth
D. Weight of the satellite
Question 24
Orbital disturbances of a geosynchronous satellite are caused by the
A. moon
B. sun
C. earth
D. all of the above
Question 25
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.
A. 0.1
B. 1
C. 2
D. 0.5
Question 26
As compared to 17.34° antenna, the total increase in the signal relayed by 4.5° antenna of INTELSAT-IV is
A. 14.85
B. 220
C. 78
D. 3.85
Question 27
For satellite communication, standard Earth stations have antenna diameters in the range of __________ metre.
A. 27.5 to 30
B. 10 to 15
C. 30 to 50
D. 5 to 10
Question 28
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
A. 10 minutes on 5 consecutive days
B. 5 minutes on 10 consecutive days
C. 30 minutes for 5 consecutive days
D. one hour for 5 consecutive days
Question 29
The most effective anti jamming technique is
A. frequency hopping
B. spread-spectrum modulation
C. key leverage
D. once-only key
Question 30
A transponder is a satellite equipment which
A. receives a signal from Earth station and amplifies
B. changes the frequency of the received signal
C. retransmits the received signal
D. does all of the above-mentioned functions
Question 31
Noise temperature of Sun is more than __________ °K.
A. 1000
B. 5000
C. 100000
D. 500
Question 32
Which of the following bands cannot be used for satellite communication?
A. MF
B. Ku
C. X
D. C
Question 33
The ending part of the popular teleserial Mahabharat will be beamed to the viewers
A. WESTAT
B. INSAT-IC
C. ARABSAT
D. INSAT-ID
Question 34
The transmitter-receiver combination in the satellite is known as a _______
A. Relay
B. Repeater
C. Transponder
D. Duplexer
Question 35
At present, the radio-frequency band mainly used by most satellites is
A. EHF
B. UHF
C. VHF
D. SHF
Question 36
The angle subtended by earth at geostationary communication satellite is
A. 17.34°
B. 51.4°
C. 120°
D. 60°
Question 37
To make antenna more directional, either its size must be increased or
A. the number of its feed horns must be increased
B. the frequency of its transmission must be increased
C. its effective isotropic radiated power (EIRP) must be increased
D. its footprint must be increased
Question 38
In a stop-and-wait ARQ system, the transmitting terminal
A. waits for positive or negative acknowled-gement from the receiving terminal after sending a block
B. sends another block if positive acknowledge is received through ACK character
C. resends the previous block if negative acknowledgement is received through a NAK character
D. does not wait for acknowledgement after sending a block
Question 39
The discussing sharing of a communication satellite by many geographically dispersed Earth station, DAMA means
A. Demand-Assigned Multiple Access
B. Decibel Attenuated Microwave Access
C. Digital Analog Master Antenna
D. Dynamically-Assigned Multiple Access
Question 40
Which technique uses two different antennas to reduce traffic on the same frequency?
A. Spatial isolation
B. Frequency reuse
C. Multiplexing
D. Modulation
Question 41
What is the reason for carrying multiple transponders in a satellite?
A. More number of operating channel
B. Better reception
C. More gain
D. Redundancy
Question 42
The first geostationary satellite launched in 1965 was called
A. ANIK
B. EARLY BIRD (Intelsat-I)
C. WESTAR
D. MOLNIYA
Question 43
Rotation of a geosynchronous satellite means its
A. drift from stationary position
B. wobbling
C. three-axis stabilization
D. three-dimensional stabilization
Question 44
Which one of the following statements regarding DSI is wrong?
A. It is a digital form of TASI
B. Though it is more efficient than TASI, it is much slower
C. A speaker has to wait (it at all) for only a few milliseconds for reallocation of channel
D. It has increased the capacity of satellite channels by a factor of 2.2 or more with out degrading speech quality
Question 45
Which one of the following statement is correct?
A. Satellite spacing is not affected by the bandwidth of the transmitting earth station
B. Beamwidth is independent of antenna size and frequency band used
C. The width of a beam in space is inversely proportional to the width of the transmitting antenna
D. Use of high-frequency bands permits less number of satellites to share the orbit
Question 46
The INTELSAT-IV satellite launched in 1974 had two earth coverage antenna and two narrower-angle antennas subtending 4.5°. The signal from narrow-angle antenna was stronger than that from earth- coverage antenna by a factor of
A. 17.34/4.5
B. 17.34 x 4.5
C. (17.34/4.5)2
D. (17.34/4.5)4
Question 47
For global communication, the number of satellites needed is
A. 1
B. 3
C. 10
D. 5
Question 48
Power received from Sun per m2 surface area of a geosynchronous satellite in nearly __________ watt.
A. 100
B. 500
C. 2000
D. 1000
Question 49
Which technique uses spot beam antennas to divide the area covered by the satellite into smaller segments?
A. Spatial isolation
B. Frequency reuse
C. Multiplexing
D. Modulation
Question 50
While keeping the down-link frequency constant, the diameter of a satellite antenna is reduced by half. To offer the same EIRP over the increased coverage area, the RF output power has to be increases by a factor of
A. 2
B. 4
C. 8
D. 16
Question 51
India's first domestic geostationary satellite 1NSAT-IA was launched on 10th April 1982 from
A. USSR
B. USA
C. UK
D. UP
Question 52
The downlink frequency is lower than the uplink frequency.
A. True
B. False
Question 53
The number of days when Earth's shadow falls on a geosynchronous satellite is
A. 88
B. 277
C. 5
D. 10