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प्रश्न
How is amplitude modulation achieved?
उत्तर
Amplitude modulation is the process of varying the amplitude of the carrier signal in accordance with the amplitude of the message signal.
Amplitude modulated signals can be produced by adding the carrier signal with the message signal and passing the resultant signal through a square law device (eg: FET). Then the signal from the square law device is passed through band pass filter to allow only the signals centered at carrier frequencies to pass. The output of the band pass filter is power amplified and transmitted by the antenna.
संबंधित प्रश्न
Draw a block diagram of a detector for AM signal and show, using necessary processes and the waveforms, how the original message signal is detected from the input AM wave.
A modulating signal is a square wave, as shown
The carrier wave is given by `c(t) = 2 sin (8pit) "volts"`
(i) Sketch the amplitude modulated waveform
(ii) What is the modulation index?
For an amplitude modulated wave, the maximum amplitude is found to be 10 V while the minimum amplitude is found to be 2 V. Determine the modulation index μ. What would be the value of μ if the minimum amplitude is zero volt?
The frequencies of two side bands in an AM wave are 640 kHz and 660 kHz respectively. Find the frequencies of carrier and modulating signal. What is the bandwidth required for amplitude modulation?
Explain any two factors which justify the need for modulating a low frequency base-band signal.
A message signal of frequency ωm is superposed on a carrier wave of frequency ωc to get an amplitude modulated wave (AM). The frequency of the AM wave will be ______.
The maximum amplitude of an A.M. wave is found to be 15 V while its minimum amplitude is found to be 3 V. What is the modulation index?
Why is a AM signal likely to be more noisy than a FM signal upon transmission through a channel?
An audio signal vm = 20sin2π(1500t) amplitude modulates a carrier vc = 80 sin 2π (100,000t). The value of percent modulation is ______.
An amplitude-modulated wave is represented by Cm(t) = 10(1 + 0.2 cos 12560t) × sin (111 × 104t) volts. The modulating frequency in kHz will be ______.
