WorksheetsSatellite Communication_ IAT-2_ part-A
Total questions: 30
Worksheet time: 30mins
Name
Class
Date
1.
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
2.
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
3.
The number of days when Earth’s shadow falls on a geosynchronous satellite is
a)
88
b)
277
c)
5
d)
10
4.
A helical antenna is used for satellite tracking because of …………..
a)
Circular polarization
b)
Maneuverability
c)
Beamwidth
d)
Gain
5.
VSAT was made available in ……..
a)
1979
b)
1981
c)
1983
d)
1977
6.
……………. collects very weak signals from a broadcast satellite
a)
Helical antenna
b)
Satellite dish
c)
LNA
d)
TWT
7.
. ………….is a loss of power of a satellite downlink signal due to earth’s atmosphere.
a)
Atmospheric loss
b)
Path loss
c)
Radiation loss
d)
RFI
8.
A satellite beam that covers almost 42.4% of the earth’s surface is called ……………
a)
Zone beam
b)
Hemispheric beam
c)
Spot beam
d)
Global beam
9.
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
10.
The angle subtended by earth at geostationary communication satellite is ………..
a)
17.34°
b)
51.4°
c)
120°
d)
60°
11.
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
12.
Radio broadcasting is a familiar example of …………….
a)
space multiplexing
b)
time multiplexing
c)
frequency multiplexing
d)
none of the above
13.
The quality of a space-link is measured in terms of the ………. ratio.
a)
C/N
b)
S/N
c)
G/T
d)
EIRP
14.
At present, the radio-frequency band mainly used by most satellites is ……….
a)
EHF
b)
UHF
c)
VHF
d)
SHF
15.
Orbital disturbances of a geosynchronous satellite are caused by the
a)
moon
b)
sun
c)
earth
d)
all of the above
16.
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
17.
What kind of battery panels are used in some advance satellites?
a)
Germanium based panels
b)
Silicon based panel
c)
Galium Phosphate solar panel array
d)
Galium Arsenide solar panel array
18.
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
19.
Power received from Sun per m2 surface area of a geosynchronous satellite in nearly…………. watt.
a)
100
b)
500
c)
2000
d)
1000
20.
What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band?
a)
3500 MHz
b)
4500 MHz
c)
2225 MHz
d)
2555 MHz
21.
The switching from one element to the other element in a typical mobile satellite array.
a)
Series
b)
Radial
c)
Matrix
d)
Shunt
22.
What circuit is responsible in activating and deactivating adjacent antenna elements in a mobile satellite array ?
a)
Radial divider
b)
Divider/combiner
c)
Radial combiner
d)
Radial multiplexer
23.
………… is defined as the use of orbiting satellites to receive, amplify and retransmit data to earth stations.
a)
Optical communication
b)
Digital communication
c)
Analog communication
d)
Satellite communication
24.
What is meant by GPRS ?
a)
General packet receiver service
b)
General packet radio service
c)
Global packet radio service
d)
none of these
25.
What is meant by EIRP?
a)
Equivalent Isotropic Radiated Power
b)
Energy Isotropic Radiated Power
c)
Equivalent Isotropic Resonance Power
d)
none of these
26.
The flux density required at the receiving antenna to produce saturation of TWTA is known as ……….
a)
Electric flux density
b)
Magnetic flux densit
c)
Saturation flux density
d)
Photon flux density
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
28.
The most effective anti jamming technique is ………..
a)
frequency hopping
b)
spread-spectrum modulation
c)
key leverage
d)
once-only key
29.
A communication satellite is a repeater between …………… and …………..
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
30.
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
100 %
