Modulation
PHXII15:COMMUNICATION SYSTEMS

356777 Modulation is used to

1 Reduce the bandwidth
2 To separate the transmission of different users
3 To ensure that intelligence may be transmitted to long distances
4 To allow the uses of practical antenna
PHXII15:COMMUNICATION SYSTEMS

356778 An AM wave is given by
\(V=1500[1+0.5 \sin 12560 t] \sin \left(5.26 \times 10^{5} t\right) .\)
The modulating frequency is

1 \(2.0kHz\)
2 \(1.0kHz\)
3 \(12.5kHz\)
4 \(50kHz\)
PHXII15:COMMUNICATION SYSTEMS

356779 A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to

1 Poor bandwidth selection of amplifiers
2 Poor selection of modulation index (selected \(0 < m < 1\) )
3 Loss of energy in transmission
4 Poor selection of carrier frequency
PHXII15:COMMUNICATION SYSTEMS

356780 If a number of sine waves with modulation indices \(\mathrm{n}_{1}, n_{2}, n_{3} \ldots \ldots . .\). Modulate a carrier wave, then total modulation index \((n)\) of the wave is

1 \(n_{1}+n_{2} \ldots .+2\left(n_{1}+n_{2} \ldots.\right)\)
2 \(\sqrt{n_{1}-n_{2}+n_{3} \ldots \ldots}\)
3 \(\sqrt{n_{1}^{2}+n_{2}^{2}+n_{3}^{2} \cdots}\)
4 None of these
PHXII15:COMMUNICATION SYSTEMS

356781 An AM wave is expressed as \(e=10(1+0.6 \cos 2000 \pi t) \cos 2 \times 10^{8} \pi t\) volts, the minimum and maximum values of modulated carrier wave are

1 \(10 \mathrm{~V}, 20 \mathrm{~V}\)
2 \(4 \mathrm{~V}, 8 \mathrm{~V}\)
3 \(16 \mathrm{~V}, 4 \mathrm{~V}\)
4 \(8 \mathrm{~V}, 20 \mathrm{~V}\)
PHXII15:COMMUNICATION SYSTEMS

356777 Modulation is used to

1 Reduce the bandwidth
2 To separate the transmission of different users
3 To ensure that intelligence may be transmitted to long distances
4 To allow the uses of practical antenna
PHXII15:COMMUNICATION SYSTEMS

356778 An AM wave is given by
\(V=1500[1+0.5 \sin 12560 t] \sin \left(5.26 \times 10^{5} t\right) .\)
The modulating frequency is

1 \(2.0kHz\)
2 \(1.0kHz\)
3 \(12.5kHz\)
4 \(50kHz\)
PHXII15:COMMUNICATION SYSTEMS

356779 A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to

1 Poor bandwidth selection of amplifiers
2 Poor selection of modulation index (selected \(0 < m < 1\) )
3 Loss of energy in transmission
4 Poor selection of carrier frequency
PHXII15:COMMUNICATION SYSTEMS

356780 If a number of sine waves with modulation indices \(\mathrm{n}_{1}, n_{2}, n_{3} \ldots \ldots . .\). Modulate a carrier wave, then total modulation index \((n)\) of the wave is

1 \(n_{1}+n_{2} \ldots .+2\left(n_{1}+n_{2} \ldots.\right)\)
2 \(\sqrt{n_{1}-n_{2}+n_{3} \ldots \ldots}\)
3 \(\sqrt{n_{1}^{2}+n_{2}^{2}+n_{3}^{2} \cdots}\)
4 None of these
PHXII15:COMMUNICATION SYSTEMS

356781 An AM wave is expressed as \(e=10(1+0.6 \cos 2000 \pi t) \cos 2 \times 10^{8} \pi t\) volts, the minimum and maximum values of modulated carrier wave are

1 \(10 \mathrm{~V}, 20 \mathrm{~V}\)
2 \(4 \mathrm{~V}, 8 \mathrm{~V}\)
3 \(16 \mathrm{~V}, 4 \mathrm{~V}\)
4 \(8 \mathrm{~V}, 20 \mathrm{~V}\)
PHXII15:COMMUNICATION SYSTEMS

356777 Modulation is used to

1 Reduce the bandwidth
2 To separate the transmission of different users
3 To ensure that intelligence may be transmitted to long distances
4 To allow the uses of practical antenna
PHXII15:COMMUNICATION SYSTEMS

356778 An AM wave is given by
\(V=1500[1+0.5 \sin 12560 t] \sin \left(5.26 \times 10^{5} t\right) .\)
The modulating frequency is

1 \(2.0kHz\)
2 \(1.0kHz\)
3 \(12.5kHz\)
4 \(50kHz\)
PHXII15:COMMUNICATION SYSTEMS

356779 A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to

1 Poor bandwidth selection of amplifiers
2 Poor selection of modulation index (selected \(0 < m < 1\) )
3 Loss of energy in transmission
4 Poor selection of carrier frequency
PHXII15:COMMUNICATION SYSTEMS

356780 If a number of sine waves with modulation indices \(\mathrm{n}_{1}, n_{2}, n_{3} \ldots \ldots . .\). Modulate a carrier wave, then total modulation index \((n)\) of the wave is

1 \(n_{1}+n_{2} \ldots .+2\left(n_{1}+n_{2} \ldots.\right)\)
2 \(\sqrt{n_{1}-n_{2}+n_{3} \ldots \ldots}\)
3 \(\sqrt{n_{1}^{2}+n_{2}^{2}+n_{3}^{2} \cdots}\)
4 None of these
PHXII15:COMMUNICATION SYSTEMS

356781 An AM wave is expressed as \(e=10(1+0.6 \cos 2000 \pi t) \cos 2 \times 10^{8} \pi t\) volts, the minimum and maximum values of modulated carrier wave are

1 \(10 \mathrm{~V}, 20 \mathrm{~V}\)
2 \(4 \mathrm{~V}, 8 \mathrm{~V}\)
3 \(16 \mathrm{~V}, 4 \mathrm{~V}\)
4 \(8 \mathrm{~V}, 20 \mathrm{~V}\)
PHXII15:COMMUNICATION SYSTEMS

356777 Modulation is used to

1 Reduce the bandwidth
2 To separate the transmission of different users
3 To ensure that intelligence may be transmitted to long distances
4 To allow the uses of practical antenna
PHXII15:COMMUNICATION SYSTEMS

356778 An AM wave is given by
\(V=1500[1+0.5 \sin 12560 t] \sin \left(5.26 \times 10^{5} t\right) .\)
The modulating frequency is

1 \(2.0kHz\)
2 \(1.0kHz\)
3 \(12.5kHz\)
4 \(50kHz\)
PHXII15:COMMUNICATION SYSTEMS

356779 A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to

1 Poor bandwidth selection of amplifiers
2 Poor selection of modulation index (selected \(0 < m < 1\) )
3 Loss of energy in transmission
4 Poor selection of carrier frequency
PHXII15:COMMUNICATION SYSTEMS

356780 If a number of sine waves with modulation indices \(\mathrm{n}_{1}, n_{2}, n_{3} \ldots \ldots . .\). Modulate a carrier wave, then total modulation index \((n)\) of the wave is

1 \(n_{1}+n_{2} \ldots .+2\left(n_{1}+n_{2} \ldots.\right)\)
2 \(\sqrt{n_{1}-n_{2}+n_{3} \ldots \ldots}\)
3 \(\sqrt{n_{1}^{2}+n_{2}^{2}+n_{3}^{2} \cdots}\)
4 None of these
PHXII15:COMMUNICATION SYSTEMS

356781 An AM wave is expressed as \(e=10(1+0.6 \cos 2000 \pi t) \cos 2 \times 10^{8} \pi t\) volts, the minimum and maximum values of modulated carrier wave are

1 \(10 \mathrm{~V}, 20 \mathrm{~V}\)
2 \(4 \mathrm{~V}, 8 \mathrm{~V}\)
3 \(16 \mathrm{~V}, 4 \mathrm{~V}\)
4 \(8 \mathrm{~V}, 20 \mathrm{~V}\)
PHXII15:COMMUNICATION SYSTEMS

356777 Modulation is used to

1 Reduce the bandwidth
2 To separate the transmission of different users
3 To ensure that intelligence may be transmitted to long distances
4 To allow the uses of practical antenna
PHXII15:COMMUNICATION SYSTEMS

356778 An AM wave is given by
\(V=1500[1+0.5 \sin 12560 t] \sin \left(5.26 \times 10^{5} t\right) .\)
The modulating frequency is

1 \(2.0kHz\)
2 \(1.0kHz\)
3 \(12.5kHz\)
4 \(50kHz\)
PHXII15:COMMUNICATION SYSTEMS

356779 A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to

1 Poor bandwidth selection of amplifiers
2 Poor selection of modulation index (selected \(0 < m < 1\) )
3 Loss of energy in transmission
4 Poor selection of carrier frequency
PHXII15:COMMUNICATION SYSTEMS

356780 If a number of sine waves with modulation indices \(\mathrm{n}_{1}, n_{2}, n_{3} \ldots \ldots . .\). Modulate a carrier wave, then total modulation index \((n)\) of the wave is

1 \(n_{1}+n_{2} \ldots .+2\left(n_{1}+n_{2} \ldots.\right)\)
2 \(\sqrt{n_{1}-n_{2}+n_{3} \ldots \ldots}\)
3 \(\sqrt{n_{1}^{2}+n_{2}^{2}+n_{3}^{2} \cdots}\)
4 None of these
PHXII15:COMMUNICATION SYSTEMS

356781 An AM wave is expressed as \(e=10(1+0.6 \cos 2000 \pi t) \cos 2 \times 10^{8} \pi t\) volts, the minimum and maximum values of modulated carrier wave are

1 \(10 \mathrm{~V}, 20 \mathrm{~V}\)
2 \(4 \mathrm{~V}, 8 \mathrm{~V}\)
3 \(16 \mathrm{~V}, 4 \mathrm{~V}\)
4 \(8 \mathrm{~V}, 20 \mathrm{~V}\)