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प्रश्न
What is the function of a bandpass filter used in a modulator for obtaining AM signal?
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उत्तर
The output produced by the square-law device is passed to the bandpass filter which rejects the dc and the sinusoids of frequencies wm, 2wm, and 2wc and retains the frequencies wc, wc – wm, and wc + wm. The output of the bandpass filter is an AM wave.
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संबंधित प्रश्न
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Explain the terms : Transmitter in communication system
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Modulator
Write the functions of the following in communication systems:
Transducer
Write the functions of the following in communication systems:
Receiver
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Distinguish between point to point and broadcast modes of communication. Give an example of each.
A basic communication system consists of ______.
- transmitter.
- information source.
- user of information.
- channel.
- receiver.
Choose the correct sequence in which these are arranged in a basic communication system:
Audio sine waves of 3 kHz frequency are used to amplitude modulate a carrier signal of 1.5 MHz. Which of the following statements are true?
- The sideband frequencies are 1506 kHz and 1494 kHz.
- The bandwidth required for amplitude modulation is 6 kHz.
- The bandwidth required for amplitude modulation is 3 MHz.
- The side band frequencies are 1503 kHz and 1497 kHz.
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