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प्रश्न
Write two advantages of frequency modulation over amplitude modulation.
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उत्तर
Following are the two advantages of frequency modulation over amplitude modulation:
1)Frequency modulation is more efficient than amplitude modulation because the amplitude of an FM wave is constant, irrespective of its modulation index. Thus, the transmitted power is constant. Also, all the transmitted power is useful in FM, whereas, in AM, most of the transmitted power goes waste in the transmitted carrier.
2) FM reception is quite immune to noise in comparison to AM reception, as noise is a form of amplitude variation in the transmitted signal. Thus, by using amplitude limiters in the FM receivers, we can almost eliminate the noise.
संबंधित प्रश्न
Explain any two factors that justify the need of modulating a low-frequency signal.
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.
What is meant by term ‘modulation’? Draw a block diagram of a simple modulator for obtaining an AM signal.
Why is frequency modulation preferred over amplitude modulation for transmission of music?
Define amplitude modulation in a communication system.
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?
On radiating (sending out) an AM modulated signal, the total radiated power is due to energy carried by ωc, ωc – ωm and ωc + ωm. Suggest ways to minimise cost of radiation without compromising on information.
