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WorksheetsEST 15
Total questions: 50
Worksheet time: 32mins
How far away is the radio horizon of an antenna 100 ft high?
14.14 mi
40 km
14.14 km
40 mi
What is the maximum line-of-sight distance between a paging antenna 250 ft high and a pager receiver 3.5 ft of the ground?
25 km
25 mi
70.73 km
70.73 mi
What is the path attenuation between transmitter and receiver at a frequency of 1.2 Ghz and a distance of 11,000 mi?
119 dB
115 dB
179 dB
174 dB
What is the uplink receiver frequency if the downlink transmitter is on channel 4 (3.84 Ghz)?
6.065 GHz
6.84 GHz
6.65 GHz
6.05 GHz
What is the maximum theoretical data rate of the above problem if one transponder is used for binary transmission?
36 Mbps
72 Mbps
18 Mbps
144 Mbps
What is the guardband between transponder channels in the commercial C-band for satellite communications?
6 MHz
36 MHz
4 MHz
2 MHz
What is the typical satellite transponder bandwidth?
24 MHz
500 MHz
36 MHz
48 MHz
What is the bandwidth available in the commercial C-band?
1000 MHz
36 MHz
250 MHz
500 MHz
Which of the following is the uplink frequency in C-band?
5.925 GHz
4.2 GHz
7.425 GHz
3.7 GHz
How many transponder channels are realized in the commercial C-band without frequency re-use?
24
12
36
48
Which band of frequencies used by military for its satellites and radar?
C band
X band
L band
P band
For navigation as well as marine and aeronautical communications and radar, ____ band is used.
L
K
S
J
What is the current frequency band given most attenuation for satellite communications?
Ku
C band
J
P
What satellite subsystem monitors onboard conditions such as temperature and battery voltage and transmits this data back to a ground station for analysis?
Communications subsystem
AKM
TTC
Transponder
Which of the following satellite subsystem provides stabilization in orbit and senses changes in orientation?
Attitude control subsystem
TTC
AKM
Transponder
What is the typical center frequency spacing between adjacent channels (transponders) in satellites?
36 MHz
40 MHz
500 MHz
4 MHz
Which of the following are uplinks in the Ku band?
14 to 14.5 GHz
11.7 to 12.2 GHz
14 to 15.5 GHz
11 to 11.5 GHz
What is considered as the most advanced satellite system developed for cellular telephones?
Iridium
Globalstar
ANIK
Molniya
What is the orbit of Motorola’s Iridium satellite system?
Polar
Equatorial
Inclined elliptical
Inclined equatorial
What band of frequencies do these satellites operate?
L band
Ka band
C band
Ku band
Iridium satellites can provide data communications of up ____ bps data rate.
1200
4800
2400
3840
What satellite system is also known as Navstar?
GPS
Iridium
Globalstar
Intelsat
What is the orbit height of a GPS satellite?
10,898 nmi
10,898 mi
10,898 km
10, 898 m
What is the orbital period of each satellite in the GPS constellation?
6 h
12 h
5 h
15 h
What term is normally associated with specifying the location of a celestial body in space?
Constellation
Galaxy
Satellite
Ephemeris
What is the angle of inclination of GPS system?
55˚
65˚
105˚
45˚
What material is most often used for the outer covering of coaxial cables?
PVC
Teflon
PE
Polystyrene
What is the dielectric constant of polyethylene (PE) insulator?
2.5
3.3
2.27
2.1
Polytetrafluoroethylene (PTFE) is also widely used insulator and is known as.
polystyrene
teflon
ceramic
bakelite
What is the characteristic impedance of a two-wire line with the following data: diameter = 0.023 in., spacing =0.5 in., insulation = PE.?
300 Ω
250 Ω
305 Ω
301 Ω
What is the characteristic impedance of a coaxial line with the following data: inner diameter = 0.2 in., center conductor diameter = 0.06 in., insulation = Teflon.
200 Ω
75 Ω
50 Ω
150 Ω
A pair of current-carrying conductors is not considered a transmission line unless it is at least ___ λ long at the signal frequency.
0.1
0.3
0.2
0.4
If the operating frequency is 450 MHz what length of a pair of conductors is considered to be a transmission line?
2.19 ft
2.19 m
0.219 ft
0.219 m
What is the physical length of the above transmission line at 3/8λ long?
0.82 m
0.82 ft
0.82 in
0.82 cm
Which of the following coaxial cable connectors is called the UHF connector?
PL-259
BNC
N-type connector
F connector
What connector is popular in attaching test instruments like oscilloscopes, frequency counters, spectrum analyzers, etc?
UHF connector
PL-259
BNC
SMA
Which coaxial cable connector is least expensive and is widely used for TV sets,VCRs and cable TV?
N-type connector
F-type connector
BNC
PL-259
Which coaxial connector is a more complex and expensive but do a better job in maintaining the electrical characteristics of the cable through the interconnections?
N-type connector
F-type connector
BNC
PL-259
The velocity factor in transmission lines vary from ___ to ___.
0.6 to 0.8
0.3 to 0.5
0.5 to 0.9
0.8 to 0.9
What is the typical velocity factor of coaxial cables?
0.6 to 0.8
0.3 to 0.5
0.5 to 0.9
0.4 to 0.6
What is the typical velocity factor of open-wire line?
0.9
0.8
0.5
0.7
What line has a typical velocity factor of about 0.8?
Shielded pair
Flexible coaxial
Twin-lead
Open-wire line
What is the velocity factor of coaxial cable with a characteristic impedance of 50 Ω and capacitance of 30 pF/ft and inductance of 75 nH/ft?
0.58
0.68
0.98
0.81
What is transit time (time delay) of a 50-ft length transmission line of the above problem?
50 ns
100 ns
75 ns
65 ns
What do you call a transmission line used specifically for the purpose of achieving delay?
Delay line
Flat line
Resonant line
Non-resonant line
What is the time delay introduced by a 75-ft coaxial cable with a dielectric constant of 2.3?
1.54 ns
11.5 ns
115.6 ns
1156 ns
Assume a frequency of 4 MHz, determine the phase shift offered by the line in the above problem.
108.5˚
106.5˚
115.5˚
166.5˚
Find the load impedance that must be used to terminate RG-62A/U to avoid reflections?
93 Ω
75 Ω
50 Ω
300 Ω
Find the equivalent inductance per foot of the above cable?
13.5 nF/ft
13.5 pF/ft
116.8 nH/ft
116.8 pF/ft
An RG-11/U foam coaxial cable has a maximum voltage standing wave of 52 V and a minimum voltage of 17 V. Find the value of the resistive load.
24.59Ω
Either A or C
228.75Ω
Neither A nor C
