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Question
How is amplitude modulation achieved?
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Solution
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.

RELATED QUESTIONS
Explain the process of amplitude modulation.
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Answer the following question.
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A message signal of frequency 20 kHz and peak voltage 10 V is used to modulate a carrier of frequency 2 MHz and peak voltage of 15 V. Calculate the modulation index. Why the modulation index is generally kept less than one?
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In amplitude modulation ______.
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