ECE - Satellite Communication Quiz (or) MCQ

1 .

Which of the following bands cannot be used for satellite communication?

A) C

B) X

C) MF

D) Ku

Correct Answer : MF

Explanation : MF is a lower frequency band than Ku, C and X bands and does not lie in the microwave spectrum. Microwaves are used for satellite communication since the lower bands get reflected by the ionosphere.

2 .

What is the maximum theoretical data rate if a transponder is used for binary transmission and has a bandwidth of 36MHz?

A) 12Mpbs

B) 32Mpbs

C) 36Mpbs

D) 72Mpbs

Correct Answer : 72Mpbs

Explanation : For binary transmission, the maximum theoretical data rate or channel capacity C for a given bandwidth B is C = 2B = 2(36) =72Mpbs.

3 .

The first geostationary satellite launched in 1965 was called

A) ANIK

B) WESTAR

C) MOLNIYA

D) EARLY BIRD (Intelsat-I)

Correct Answer : EARLY BIRD (Intelsat-I)

4 .

Rotation of a geosynchronous satellite means its

A) wobbling

B) three-axis stabilization

C) drift from stationary position

D) three-dimensional stabilization

Correct Answer : wobbling

5 .

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) 1

B) 4

C) 10

D) 100

Correct Answer : 4

6 .

The noise temperature of sky is about __________ °K.

A) 30

B) 100

C) 270

D) 0

Correct Answer : 30

7 .

The different access methods which permit many satellite users to operate in parallel through a single transponder without interfering with each other as

A) Time Division Multiple Access (TDMA)

B) Code Division Multiple Access (CDMA)

C) Frequency Division Multiple Access (FDMA)

D) All of the above

Correct Answer : All of the above

8 .

Assuming earth to be a sphere of radius 6400 km and height of a geosynchronous satellite above Earth as 36000 km, the velocity of a geosynchronous satellite is __________ km/hr.

A) 11100

A)

B) 15000

B)

C) 28000

C)

D) 36000

D)

Correct Answer : 11100

9 .

Noise temperature of Sun is more than __________ °K.

A) 500

B) 1000

C) 5000

D) 100000

Correct Answer : 100000

10 .

The present total cost per watt of power generation in geosynchronous orbit is nearly Rs.

A) 100

B) 50

C) 20

D) 10

Correct Answer : 20

11 .

In the context of error detection in satellite transmission, ARQ stands for

A) Automatic Relay Request

B) Automatic Repeat Request

C) Accelerated Recovery Request

D) Automatic Radiation Quenching

Correct Answer : Automatic Repeat Request

12 .

To cover all inhabited regions of the Earth, the number of geosynchronous communication satellites required

A) 3

B) 4

C) 5

D) 10

Correct Answer : 3

13 .

The satellite that is used as a relay to extend communication distance is called as ______

A) Relay satellites

B) Repeater satellites

C) Communication satellites

D) Geosynchronous satellites

Correct Answer : Communication satellites

Explanation : Communication satellites are not originators of information to be transmitted. If a transmitting station cannot communicate directly with one or more receiving stations because of line-of-sight restrictions, a satellite can be used. The transmitting station sends the information to the satellite, which in turn re-transmits it to the receiving stations.

14 .

The transmitter-receiver combination in the satellite is known as a ______

A) Relay

B) Duplexer

C) Repeater

D) Transponder

Correct Answer : Transponder

Explanation : The transmitter-receiver combination in the satellite is known as a transponder. The basic functions of a transponder are amplification and frequency translation. The reason for frequency translation is that the transponder cannot transmit and receive on the same frequency.

15 .

Collects very weak signals from a broadcast satellite

A) LNA

B) TWT

C) Satellite dish

D) Helical antenna

Correct Answer : Satellite dish

16 .

Is a loss of power of a satellite downlink signal due to earth’s atmosphere.

A) Path loss

B) RFI

C) Radiation loss

D) Atmospheric loss

Correct Answer : Path loss

17 .

Considered as the unsolved problem in satellite system

A) Cost

B) Privacy

C) Access

D) Coverage

Correct Answer : Privacy

18 .

What is the reason for carrying multiple transponders in a satellite?

A) More gain

B) Redundancy

C) Better reception

D) More number of operating channel

Correct Answer : More number of operating channel

Explanation : To be economically feasible, a satellite must be capable of handling several channels. As a result, most satellites contain multiple transponders, each operating at a different frequency. Each transponder represents an individual communication channel.

19 .

Why are VHF, UHF, and microwave signals used in satellite communication?

A) More bandwidth

B) Economically viable

C) More spectrum space

D) Are not diffracted by the ionosphere

Correct Answer : Are not diffracted by the ionosphere

Explanation : VHF, UHF, and microwave signals penetrate the ionosphere with little or no attenuation and are not refracted to earth. Lower frequencies undergo total internal refraction and get reflected back to earth.

20 .

As the height of a satellite orbit gets lower, the speed of the satellite ___________.

A) Increases

B) Decreases

C) Remains the same

D) None of the above

Correct Answer : Increases

21 .

A satellite beam that covers almost 42.4% of the earths surface.

A) Spot beam

B) Zone beam

C) Global beam

D) Hemispheric beam

Correct Answer : Global beam

22 .

The discussing sharing of a communication satellite by many geographically dispersed Earth station, DAMA means

A) Digital Analog Master Antenna

B) Demand-Assigned Multiple Access

C) Dynamically-Assigned Multiple Access

D) Decibel Attenuated Microwave Access

Correct Answer : Demand-Assigned Multiple Access

23 .

The angle subtended by earth at geostationary communication satellite is

A) 17.34°

B) 51.4°

C) 60°

D) 120°

Correct Answer : 17.34°

24 .

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

A) 273

B) 243

C) 170

D) 123

Correct Answer : 123

25 .

India's first three-axis stabilised geostationary communication satellite is

A) Rohini

B) Apple

C) Bhaskara

D) Aryabhatta

Correct Answer : Apple

26 .

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

A)

B) 17.34 x 4.5

B)

C) (17.34/4.5)²

C)

D) (17.34/4.5)⁴

D)

Correct Answer : (17.34/4.5)²

27 .

A geosynchronous satellite

A) has a circular orbit

B) rotates in the equatorial plane

C) has the same period a that of the Earth

D) has all of the above

Correct Answer : has all of the above

28 .

A transponder is a satellite equipment which

A) retransmits the received signal

B) changes the frequency of the received signal

C) does all of the above-mentioned functions

D) receives a signal from Earth station and amplifies

Correct Answer : does all of the above-mentioned functions

29 .

In envelope detection of an AM waveform

A) Only two side bands are needed

B) Upper side band and part of carrier are needed

C) Both side bands and full-amplitude carrier are needed

D) One side band and full-ampiitude carrier are needed

Correct Answer : Both side bands and full-amplitude carrier are needed

30 .

Shannon's Law relates

A) noise power to bandwidth

B) antenna gain to frequency

C) transmission losses to noise

D) information-carrying capacity to S/N ratio

Correct Answer : noise power to bandwidth

31 .

What is the reason for shifting from c band to ku band in satellite communication?

A) More bandwidth

B) Overcrowding

C) Lesser attenuation

D) Less power requirements

Correct Answer : Overcrowding

Explanation : Most new communication satellites will operate in the Ku band. This upward shift in frequency is happening because the C band is overcrowded. Many communication satellites are in orbit now, most of them operating in the C band. However, there is some difficulty with interference because of the heavy usage. The only way this interference will be minimized is to shift all future satellite communication to higher frequencies.

32 .

Why are techniques like frequency reuse and spatial isolation carried out?

A) More gain

B) High speed

C) Error detection

D) Reduce traffic load

Correct Answer : Reduce traffic load

Explanation : at times there is more traffic than there are transponders to handle it. For that reason, numerous techniques have been developed to effectively increase the bandwidth and signal-carrying capacity of the satellite. Two of these techniques are known as frequency reuse and spatial isolation.

33 .

Most mobile satellite array uses ___________ in transforming 50 to 150 Ω impedance.

A) Stub

B) Balun

C) Microstrip tapers

D) Quarter-wavelength transformer

Correct Answer : Quarter-wavelength transformer

34 .

A satellite signal transmitted from a satellite transponder to earth's station.

A) Uplink

B) Terrestrial

C) Downlink

D) Earthbound

Correct Answer : Downlink

35 .

VSAT was made available in

A) 1979

B) 1981

C) 1983

D) 1985

Correct Answer : 1979

36 .

What band does VSAT first operate?

A) L-band

B) C-band

C) X-band

D) Ku-band

Correct Answer : C-band

37 .

A helical antenna is used for satellite tracking because of

A) Gain

B) Beamwidth

C) Maneuverability

D) Circular polarization

Correct Answer : Circular polarization

38 .

To make antenna more directional, either its size must be increased or

A) its footprint must be increased

B) the number of its feed horns must be increased

C) the frequency of its transmission must be increased

D) its effective isotropic radiated power (EIRP) must be increased

Correct Answer : the frequency of its transmission must be increased

39 .

The number of days when Earth's shadow falls on a geosynchronous satellite is

A) 2

B) 10

C) 88

D) 277

Correct Answer : 88

40 .

India's first domestic geostationary satellite 1NSAT-IA was launched on 10th April 1982 from

A) UK

B) USA

C) USSR

D) None of the above

Correct Answer : USA

41 .

A modem is______

A) a form of commutator

B) a device for digitizing speech

C) a circuit used for suppressing microwave mterference

D) an electronic circuit which carries out modulation and demodulation of a carrier frequency

Correct Answer : an electronic circuit which carries out modulation and demodulation of a carrier frequency

42 .

In synchronous detection of an AM signal

A) Only one side band and part of carrier is suppressed

B) Carrier is completely suppressed

C) Both side hands are suppressed

D) One side band and full carrier is suppressed

Correct Answer : Only one side band and part of carrier is suppressed

43 .

Assuming a minimum angle of elevation of 5°, a geosynchronous satellite remains in line-of-sight for __________ percentage of Earth's surface.

A) 25

B) 30.3

C) 42.4

D) 50

Correct Answer : 25

44 .

A typical signal strength received from a geosynchronous communication satellite is of the order of a few

A) watts

B) picowatts

C) kilowatts

D) milliwatts

Correct Answer : picowatts

45 .

Satellite launch sites are invariably located on Eastern seaboards to ensure that

A) launch takes place eastward

B) the satellite achieves circular orbit quickly

C) spent rocket motor and other launcher debris falls into the sea

D) expenditure of propulsion fuel is reduced during plane changing

Correct Answer : spent rocket motor and other launcher debris falls into the sea

46 .

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

A)

B) 0.5

B)

C) 1.0

C)

D) 2.0

D)

Correct Answer : 0.1

47 .

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

Correct Answer : INSAT-IB

48 .

Radio broadcasting is a familiar example of

A) time multiplexing

B) space multiplexing

C) Both (A) and (B)

D) frequency multiplexing

Correct Answer : frequency multiplexing

49 .

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

A) one frequency is used as a back up for the other

B) the system operates at a mean frequency of 5 GHz

C) 4 GHz is the down-link and 6 GHz is the up-link frequency

D) 4 GHz is the up-link and 6 GHz is the down-link frequency

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

50 .

Which technique uses spot beam antennas to divide the area covered by the satellite into smaller segments?

A) Spatial isolation

B) Modulation

C) Multiplexing

D) Frequency reuse

Correct Answer : Spatial isolation

Explanation : By using narrow beam or spot beam antennas, the area on the earth covered by the satellite can be divided up into smaller segments. Earth stations in each segment may actually use the same frequency, but because of the very narrow beam widths of the antennas, there is no interference between adjacent segments.

51 .

Which technique uses two different antennas to reduce traffic on the same frequency?

A) Modulation

B) Multiplexing

C) Spatial isolation

D) Frequency reuse

Correct Answer : Frequency reuse

Explanation : In the frequency reuse technique two systems use the same frequency, although operating on exactly the same frequencies, they are isolated from each other by the use of special antenna techniques.

For example, a vertically polarized antenna will not respond to a horizontally polarized signal and vice versa. Or a left-hand circularly polarized (LHCP) antenna will not respond to a right-hand circularly polarized (RHCP) signal and vice versa.

52 .

Spatial-division multiple access (SDMA) depends on satellite location and not frequency.

A) True

B) False

C) Can Not Say

D) None of the above

Correct Answer : True

Explanation : Spatial-division multiple access uses spatial isolation technique. Earth stations in each segment may actually use the same frequency, but because of the very narrow beam widths of the antennas, there is no interference between adjacent segments.

This technique is referred to a spatial-division multiple access (SDMA) in that access to the satellite depends on location and not frequency.

53 .

The downlink frequency is lower than the uplink frequency.

A) True

B) False

C) Can Not Say

D) None of the above

Correct Answer : True

Explanation : The original signal being transmitted from the earth station to the satellite is called the uplink, and the re-transmitted signal from the satellite to the receiving stations is called the downlink.

Usually, the downlink frequency is lower than the uplink frequency. A typical uplink frequency is 6 GHz, and a common downlink frequency is 4 GHz.

54 .

Satellite engine uses____

A) Solar jet

B) Liquid fuel

C) Jet propulsion

D) Ion propulsion system

Correct Answer : Ion propulsion system

55 .

The earth area covered by a satellite radio beam.

A) Zone

B) Footprint

C) Bandwidth

D) Beamwidth

Correct Answer : Footprint

56 .

What kind of battery used by older satellites?

A) Lithium

B) Leclanche

C) Hydrogen

D) Magnesium

Correct Answer : Hydrogen

57 .

The bandwidth of C-band satellite frequency band in U.S.

A) 500 MHz

B) 500 GHz

C) 1000 MHz

D) 1000 GHz

Correct Answer : 500 MHz

58 .

The location of AsiaSat 1.

A) 105.5° East

B) 115.5° East

C) 151.5° East

D) 170.5° East

Correct Answer : 105.5° East

59 .

The most common device used as an LNA is

A) IMPATT

B) Zener diode

C) Shockley diode

D) Tunnel diode

Correct Answer : Tunnel diode

60 .

Repeaters inside communications satellites are known as

A) TWT

B) Transponders

C) Trancievers

D) Transducers

Correct Answer : Transponders

61 .

As compared to 17.34° antenna, the total increase in the signal relayed by 4.5° antenna of INTELSAT-IV is

A) 3.85

B) 14.85

C) 78

D) 220

Correct Answer : 220

62 .

Which one of the following statements regarding compandor is FALSE?

A) It gives preferential treatment to the weaker parts of the signal

B) Weaker signals, traverse more quantum steps than they would do otherwise and so quantizing error is reduced.

C) For weaker signals it gives a poor ratio of signal strength to quantizing error

D) It compresses the higher-amplitude parts of a signal before modulation and expands them back to normal again after demodulation.

Correct Answer : For weaker signals it gives a poor ratio of signal strength to quantizing error

63 .

Which one of the following statements regarding DSI is wrong?

A) Though it is more efficient than TASI, it is much slower

B) It is a digital form of TASI

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

Correct Answer : Though it is more efficient than TASI, it is much slower

64 .

APPLE was into orbit on 19 th June 1981 by European Space Agency (ESA) from

A) Bangalore in South India

B) Cape Canaveral in Florida

C) Kourou in French Guyana

D) Canarvon in Western Australia

Correct Answer : Kourou in French Guyana

65 .

A telephone user while talking to a person via a satellite has to wait for reply for about __________ millisecond.

A) 470

B) 540

C) 270

D) 100

Correct Answer : 540

66 .

Which of the following statement regarding link loss for a satellite is wrong?

A) For fixed antenna, it is inversely proportional to f2

B) Loss in down-link is negligible as compared to that in uplink

C) For a given satellite operating at a given frequency, it is inversely proportional to

D) For fixed frequency, it is inversely proportional to the product of the antenna aperture areas

Correct Answer : Loss in down-link is negligible as compared to that in uplink

67 .

Space communication links are being increasingly moved into Ka-band (200-30 GHz) because it

A) permits the use of smaller antenna

B) does not suffer from rain attenuation

C) does not suffer from atmospheric at tenuation

D) offers a much wider available bandwidth

Correct Answer : offers a much wider available bandwidth

68 .

The quality of a space-link is measured in terms of the __________ ratio.

A) C/N

B) G/T

C) S/N

D) EIRP

Correct Answer : C/N

69 .

The useful operational life of INSAT-IB (launched in 1983) is expected to end by

A) 1989-90

B) 1991-92

C) 1992-93

D) 1993-94

Correct Answer : 1989-90

70 .

At present, the radio-frequency band mainly used by most satellites is

A) EHF

B) UHF

C) SHF

D) VHF

Correct Answer : SHF

71 .

Orbital disturbances of a geosynchronous satellite are caused by the

A) sun

B) earth

C) moon

D) All of the above

Correct Answer : All of the above

72 .

Depending on the technique used, digitized television requires a bit rate between __________ millions.

A) 2

B) 25 and 60

C) 30 and 82.5

D) 40 and 92.5

Correct Answer : 40 and 92.5

73 .

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

A) loss of power

B) battery power provision

C) eclipse period

D) mass of station-keeping fuel

Correct Answer : battery power provision

74 .

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

A) sun-synchronous polar

B) polar

C) equatorial

D) geostationary

Correct Answer : sun-synchronous polar

75 .

In selecting a satellite system, the First determining factor is its

A) EIRP

B) antenna size

C) coverage a sea

D) antenna gain

Correct Answer : coverage a sea

76 .

Phase modulation is commonly-used for data transmission mainly because

A) it is resistant to the effects of noise

B) demodulation is very easy

C) phase can be varied from + 180° to 180°

D) it gives highest data rates that can be transmitted over a given channel

Correct Answer : it is resistant to the effects of noise

77 .

What kind of battery panels are used in some advance satellites

A) Silicon based panel

B) Galium Arsenide solar panel array

C) Germanium based panels

D) Galium Phosphate solar panel array

Correct Answer : Galium Arsenide solar panel array

78 .

A satellite batter has more power but lighter.

A) Leclanche

B) Lithium

C) Hydrogen

D) Magnesium

Correct Answer : Lithium

79 .

The radiation patterns of earth coverage antennas have a beamwidth of approximately

A) 5°

B) 17°

C) 21°

D) 35°

Correct Answer : 17°

80 .

What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band?

A) 2225 MHz

B) 2555 MHz

C) 3500 MHz

D) 4500 MHz

Correct Answer : 2225 MHz

81 .

The switching from one element to the other element in a typical mobile satellite array.

A) Series

B) Radial

C) Shunt

D) Matrix

Correct Answer : Shunt

82 .

In a stop-and-wait ARQ system, the transmitting terminal

A) does not wait for acknowledgement 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) waits for positive or negative acknowled-gement from the receiving terminal after sending a block

Correct Answer : does not wait for acknowledgement after sending a block

83 .

A certain sound has 10000 times more energy than another sound. The number of times it would sound stronger to a listener is

A) 10

B) 40

C) 100

D) 1000

Correct Answer : 40

84 .

Power received from Sun per m² surface area of a geosynchronous satellite in nearly __________ watt.

A) 100

B) 500

C) 1000

D) 2000

Correct Answer : 1000

85 .

A geostationary satellite is one which

A) remains stationary above the Earth

B) travels around the Earth in 24 hours

C) hangs motionless in space about 36000 km about Earth

D) appears stationary to everybody on Earth

Correct Answer : appears stationary to everybody on Earth

86 .

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 of the above

Correct Answer : many transmitting station and many receiving station

87 .

For satellite communication, standard Earth stations have antenna diameters in the range of __________ metre.

A) 27.5 to 30

B) 5 to 10

C) 10 to 15

D) 30 to 50

Correct Answer : 27.5 to 30

88 .

The most effective anti jamming technique is

A) key leverage

B) spread-spectrum modulation

C) once-only key

D) frequency hopping

Correct Answer : spread-spectrum modulation

89 .

The ending part of the popular teleserial Mahabharat will be beamed to the viewers

A) WESTAT

B) INSAT-IC

C) INSAT-ID

D) ARABSAT

Correct Answer : ARABSAT

90 .

The degradation of satellite solar cells with time is mainly due to

A) collection of meteoric dust

B) increase in resistivity of silicon

C) their bombardment by electrons

D) gradual leakage of charge carriers from the semiconductor material

Correct Answer : their bombardment by electrons

91 .

A satellite link uses different frequencies for receiving and transmitting in order to

A) maximise antenna gain

B) minimise free-space losses

C) avoid interference from terrestrial microwave links

D) avoid interference between its powerful transmitted signal and weak in coming signal

Correct Answer : avoid interference between its powerful transmitted signal and weak in coming signal

92 .

The echo heard by a telephone user on a satellite channel can be removed by using

A) echo suppressor

B) a vocoder

C) a multiplexer

D) digital techniques

Correct Answer : echo suppressor

93 .

The 1150 kg geosynchronous satellite INSAT-IA parked 36000 km above India had greatly improved India's

A) intelligence gathering capacity

B) domestic communications

C) meteorological capability

D) Both (B) and (C)

Correct Answer : Both (B) and (C)

94 .

Presently, the worlds's largest and most advanced multi-purpose communication satellite is

A) INSAT-2

B) Olympus-I

C) INSAT-ID

D) Intelsat-V

Correct Answer : Olympus-I

95 .

What circuit is responsible in activating and deactivating adjacent antenna elements in a mobile satellite array?

A) Divider/combiner

B) Radial combiner

C) Radial divider

D) Radial multiplexer

Correct Answer : Radial divider

96 .

The frequency of Ku band for satellite communications.

A) 4 - 8 GHz

B) 8 - 12 GHz

C) 12 - 18 GHz

D) 26 - 40 GHz

Correct Answer : 12 - 18 GHz

97 .

Point on the satellite obits closest to the earth.

A) Perigee

B) Zenith

C) Apogee

D) Prograde

Correct Answer : Perigee

98 .

A method of multiple accessing where a given RF channel bandwidth is divided inot smaller frequency band.

A) TDMA

B) CDMA

C) ANIK-D

D) FDMA

Correct Answer : FDMA

99 .

INTELSAT stands for

A) Intel Satellite

B) International Satellite

C) International Telephone Satellite

D) International Telecommunications Satellite

Correct Answer : International Telecommunications Satellite

100 .

A satellite cross-link means

A) Satellite-to-earth link

B) Satellite-to-satellite link

C) Earth-to-satellite link

D) None of the above

Correct Answer : Satellite-to-satellite link

101 .

A colour television signal having bandwidth of 4.6 MHz is digitised using 10 bits sample. The digital bit rate used for its transmission with PCM would be __________ kilobits/second.

A) 230

A)

B) 920

B)

C) 23000

C)

D) 92000

D)

Correct Answer : 92000

102 .

Master control facility (MCF) for INSAT-2 series satellites is located at

A) Leh

B) Madras

C) Hassan

D) New Delhi

Correct Answer : Hassan

103 .

The distance of a synchronous satellite from Earth's surface is __________ km.

A) 5

B) 300

C) 10000

D) 35900

Correct Answer : 35900

104 .

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) 5 minutes on 10 consecutive days

B) 10 minutes on 5 consecutive days

C) 30 minutes for 5 consecutive days

D) one hour for 5 consecutive days

Correct Answer : 10 minutes on 5 consecutive days

105 .

In satellite communication, frequency modulation is used because satellite channel has

A) large bandwidth and severe noise

B) high modulation index

C) small bandwidth and negligible noise

D) maximum bandwidth and minimum noise

Correct Answer : large bandwidth and severe noise

106 .

In communication satellites, the up-link normally operates at a higher frequency than the down-link because it

A) gives better beam-shaping

B) results in lesser signal attenuation

C) gives a narrow beam shining into space

D) is easier to polarize a high frequency beam

Correct Answer : gives a narrow beam shining into space

107 .

Which of the following factor does NOT contribute to the drift of a geostationary satellite from its stationary position in space?

A) Oblateness of the Earth

B) Pressure of solar radiations

C) Weight of the satellite

D) Gravitational changes due to Sun and Moon

Correct Answer : Weight of the satellite

108 .

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) 34 and 142

D) 106 and 142

Correct Answer : 52 and 88

109 .

For global communication, the number of satellites needed is

A) 1

B) 3

C) 5

D) 10

Correct Answer : 3

110 .

Geosynchronous communication satellites travel around the earth in circular orbits with a forward speed of about __________ km/h.

A) 36000

B) 33070

C) 22800

D) 11200

Correct Answer : 11200

111 .

Low-orbit satellites are not used for communications because they

A) heat up and melt

B) produce sonic booms

C) do not provide 24 hour/ day contact to the users on Earth

D) None of the above

Correct Answer : heat up and melt

112 .

The average noise temperature of Earth, as viewed from space, is _______°K.

A) 500

B) 303

C) 254

D) 100

Correct Answer : 254

113 .

In satellite communication, highly directional antennas are used to

A) strengthen the beam to overcome the cosmic noise

B) direct the spot beam to a particular region of space on Earth

C) make corrections in change of polarisation of the beam

D) select a particular channel in transmission and reception

Correct Answer : direct the spot beam to a particular region of space on Earth

114 .

After the death of INSAT-IB, the mainstay of the entire Indian satellite network for some time to come would be

A) ARABSAT

B) INSAT-2

C) INSAT-ID

D) INSTELSAT-V

Correct Answer : ARABSAT

115 .

The maximum signal propagation time of a geosynchronous satellite transmission is about __________ millisecond.

A) 135

B) 270

C) 540

D) 1080

Correct Answer : 270

116 .

The life time of a geosynchronous communication

A) 50

B) 40

C) 20

D) 10

Correct Answer : 10

117 .

For satellite transmission, analog signals may be converted into digital form with the help of

A) modem

B) codec

C) compandor

D) transponder

Correct Answer : codec

118 .

The traffic-handling capacity of an Earth station on the uplink depends on

A) its EIRP

B) satellite antenna gain

C) noise associated with the satellite

D) All of the above

Correct Answer : All of the above

119 .

A few minutes disturbance in space communications occurs twice a year during Sunblinding when __________ are in line.

A) Sun and satellite

B) Sun and Earth station

C) Satellite and Earth station

D) Sun, satellite and Earth station

Correct Answer : Sun, satellite and Earth station

120 .

Geosynchronous satellites are always launched in the equatorial plane because it is the only plane which provides

A) global communication

B) 24-hour orbit

C) stationary satellite

D) zero-gravity environs

Correct Answer : global communication

121 .

System satellites orbit the Earth once in

A) 1 hours

B) 12 hours

C) 24 hours

D) 48 hours

Correct Answer : 24 hours

122 .

The lowest frequency used in satellite communications is __________ GHz.

A) 0.8

B) 3

C) 18

D) 30

Correct Answer : 0.8

123 .

The smallest beam of a satellite antenna radiation pattern

A) Zone beam

B) Spot beam

C) Global beam

D) Hemispheric beam

Correct Answer : Spot beam

124 .

Which of the following is the first commercial satellite?

A) Courier

B) Explorer

C) Early Bird

D) Telstar

Correct Answer : Telstar

125 .

___________ is a satellite that rotates around the earth in a low-altitude elliptical or circular pattern.

A) Prograde satellite

B) Retrograde satellite

C) Nonsynchronous satellite

D) Geosynchronous satellite

Correct Answer : Nonsynchronous satellite

126 .

The first Philippine Mabuhay satellite has how many channels?

A) 24

B) 30

C) 48

D) 50

Correct Answer : 30

127 .

Which of the following is the first active satellite?

A) Sputnik I

B) Echo I

C) Telstar I

D) Early Bird

Correct Answer : Sputnik I

128 .

A mobile satellite array has usually how many elements?

A) 6

B) 12

C) 14

D) 80

Correct Answer : 14

129 .

The owner of AsiaSat 2 is

A) Japan Satellite System (JSAT)

B) Singapore Satellite Commision

C) Asia Satellite Telecommunications Company (ASTC)

D) China Great Wall Industry Corporation

Correct Answer : China Great Wall Industry Corporation

130 .

What height must a satellite be placed above the surface of the earth in order for its rotation to be equal to earth's rotation?

A) 22,426.4 miles

B) 23,426.4 miles

C) 26,426.4 miles

D) 27,426.4 miles

Correct Answer : 22,426.4 miles

ECE : Satellite Communication MCQs with Answers