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PHXII15:COMMUNICATION SYSTEMS

356854 AM is used for broadcasting because

1 It is more noise immune than other modulating systems

2 It requires less transmitting power compared with other systems

3 Its use avoids receiver complexity (or) It is simple to demodulate

4 No other modulation system can provide the necessary bandwidth, faithful transmission

PHXII15:COMMUNICATION SYSTEMS

356855 In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density $10^{11}$ per $m^{3}$

1

2 M H z

2

10 M H z

3

12 M H z

4

18 M H z

Explanation:

By using $f_{c} \approx 9 {(N_{max})}^{1 / 2} \Rightarrow f_{c} \approx 2 M H z$ .

PHXII15:COMMUNICATION SYSTEMS

356856 The ground wave eventually disappears, as one moves away from the transmitter, because of

1 Interference from the sky wave

2 Loss of line of signal condition

3 Maximum single - hop distance limitation

4 Difdfraction effect causing tilting of the wave

PHXII15:COMMUNICATION SYSTEMS

356857 Broadcasting antennas are generally

1 Omnidirectional type

2 Vertical type

3 Horizontal type

4 None of these

PHXII15:COMMUNICATION SYSTEMS

356854 AM is used for broadcasting because

1 It is more noise immune than other modulating systems

2 It requires less transmitting power compared with other systems

3 Its use avoids receiver complexity (or) It is simple to demodulate

4 No other modulation system can provide the necessary bandwidth, faithful transmission

PHXII15:COMMUNICATION SYSTEMS

356855 In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density $10^{11}$ per $m^{3}$

1

2 M H z

2

10 M H z

3

12 M H z

4

18 M H z

Explanation:

By using $f_{c} \approx 9 {(N_{max})}^{1 / 2} \Rightarrow f_{c} \approx 2 M H z$ .

PHXII15:COMMUNICATION SYSTEMS

356856 The ground wave eventually disappears, as one moves away from the transmitter, because of

1 Interference from the sky wave

2 Loss of line of signal condition

3 Maximum single - hop distance limitation

4 Difdfraction effect causing tilting of the wave

PHXII15:COMMUNICATION SYSTEMS

356857 Broadcasting antennas are generally

1 Omnidirectional type

2 Vertical type

3 Horizontal type

4 None of these

PHXII15:COMMUNICATION SYSTEMS

356854 AM is used for broadcasting because

1 It is more noise immune than other modulating systems

2 It requires less transmitting power compared with other systems

3 Its use avoids receiver complexity (or) It is simple to demodulate

4 No other modulation system can provide the necessary bandwidth, faithful transmission

PHXII15:COMMUNICATION SYSTEMS

356855 In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density $10^{11}$ per $m^{3}$

1

2 M H z

2

10 M H z

3

12 M H z

4

18 M H z

Explanation:

By using $f_{c} \approx 9 {(N_{max})}^{1 / 2} \Rightarrow f_{c} \approx 2 M H z$ .

PHXII15:COMMUNICATION SYSTEMS

356856 The ground wave eventually disappears, as one moves away from the transmitter, because of

1 Interference from the sky wave

2 Loss of line of signal condition

3 Maximum single - hop distance limitation

4 Difdfraction effect causing tilting of the wave

PHXII15:COMMUNICATION SYSTEMS

356857 Broadcasting antennas are generally

1 Omnidirectional type

2 Vertical type

3 Horizontal type

4 None of these

PHXII15:COMMUNICATION SYSTEMS

356854 AM is used for broadcasting because

1 It is more noise immune than other modulating systems

2 It requires less transmitting power compared with other systems

3 Its use avoids receiver complexity (or) It is simple to demodulate

4 No other modulation system can provide the necessary bandwidth, faithful transmission

PHXII15:COMMUNICATION SYSTEMS

356855 In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density $10^{11}$ per $m^{3}$

1

2 M H z

2

10 M H z

3

12 M H z

4

18 M H z

Explanation:

By using $f_{c} \approx 9 {(N_{max})}^{1 / 2} \Rightarrow f_{c} \approx 2 M H z$ .

PHXII15:COMMUNICATION SYSTEMS

356856 The ground wave eventually disappears, as one moves away from the transmitter, because of

1 Interference from the sky wave

2 Loss of line of signal condition

3 Maximum single - hop distance limitation

4 Difdfraction effect causing tilting of the wave

PHXII15:COMMUNICATION SYSTEMS

356857 Broadcasting antennas are generally

1 Omnidirectional type

2 Vertical type

3 Horizontal type

4 None of these